Docker setup

Get bits working in lightweight containers

Overview

VMs on MacOS vs. Docker
Docker for Mac
- Recap
Alternatives to Docker
Linux installer boots
Setup Shell Script
- GPG SecureApt
Install Docker on MacOS
- Manual Docker for Mac
- Clean up the installer
- Open Docker client app
- Previously
Install Docker on Windows 10+
- Install in Amazon EC2 clouds
- Install local Windows 10
- Chocolatey
- Manual install
- Default folders
Alpine Linux
Install Docker in CentOS
- Install Docker on Windows 10
After install, Menu, Verify
- Full Docker Info
- Container Registries
- Setup Docker Hub
- List and remove image
- Setup Credential Store
- Log into Docker Hub
- Troubleshoot Docker daemon start
- Modules installed
Set Maximum File Descriptors
Run from Docker Hub
- Docker Help
- Docker terminal inside the container
- Docker pull
- Dockviz
- Base DockerHub Search
- Windows Insider Images
- Ubuntu search
  - Quay.io private Dockerfiles
Run Dockerfile from GitHub
- Run from my GitHub
- Other Dockerfiles from GitHub
- Run Latest Nginx from Docker Hub
MySQL
Dependencies in Docker
- MySQL security
Run custom reference
Ubuntu inside Mac
- List Docker Containers
- Manage Images Downloaded
- Configre Docker client
- Remove images
- No Error Report
- Start using old boot2docker
Stop
docker-machine install
- Create Docker machine
Docker Compose
Kubernetes
- Monitoring
Docker Swarm
Debug within container
More on DevOps

The object of this tutorial is a succinct yet deep step-by-step instructions to setup of Docker on MacOS, CentOS Linux, and Windows.

VMs on MacOS vs. Docker

This is a more complex diagram than others so that interrelationships can be illustrated. TODO: Video to gradually reveal this.

docker flowchart v04-650x312-97kb
Click this for a pop-up containing a larger sized image.

Prior to Docker, a developer working on a Mac Pro can, in addition to native apps for Mac, also run Microsoft Visual Studio for Windows in a full install of Windows 10 by running them within a VMware Fusion or Vagrant hypervisor that manages Virtual Memory instances. See https://www.upguard.com/articles/docker-vs-vagrant

Each additional VM (virtual machine) instance would take several more Gigabytes of disk space and memory because operating system files are duplicated inside each VM instance.

By contrast, Docker’s containers take a more lightweight approach. Docker aims to cleanly separate applications that need the same shared operating system read-only files.

Docker for Mac

The Docker for Mac installer is downloaded from Docker’s website. It makes use of hypervisor software that doesn’t need Oracle’s Virtualbox previously needed.

Docker for Mac makes use of a Hyperkit hypervisor which runs Docker images such as NGINX.

Later Macs have Intel’s hardware support for MMU (memory management unit) EPT (Extended Page Tables) virtualization.

Docker images are obtained from Docker Hub on-line or a more private and trusted image repository. Many images are visible searches within Docker Hub.

That same container image can run on another platform unchanged, typically a GNU/Linux kernel such as Debian running on a commodity server within AWS EC2 cloud. Docker is designed with cloud computing providers in mind.

The Docker Engine takes care of loading images and running them. It is installed from the package manager over the internet.

Docker is lighter weight because it provides the read-only portion of a Linux operating system to be shared among several images. Each image has its own bin and lib folders.

Docker is also lightweight and thus more scalable because each image intends to run and watch one single process. SSH ports are not opened into images.

A data volume outside the image is referenced to read private keys.

Additional data volumes (such as InfluxDB) are shared for logging with an additional image. It receives stats collected by the cAdvisor image (from Google) and structures data for display in a Grafana dashboard.

Images that go into container repositories are created by a build command in Docker for Mac and Windows. The build is based on source code for an app in GitHub having a Dockerfile and .dockerignore file.

Docker for Mac was released in 2016 as a native app that keeps itself updated, so no Homebrew for it as with previous versions. This new version makes use of 64-bit processor in a 2010 or newer Mac, which has Intel’s hardware support for virtualization. The operating system is MacOS Yosemite version 10.10 or newer, such as El Capitan 10.11 or Sierra 10.12.

Docker for Mac uses underlying software not in prior versions, so NO obsoleted docker-machine commands that load and manage images depend on the installation of Virtualbox by the deprecated Docker Toolbox.

Recap

docker flowchart v04-650x312-97kb
Click this for a pop-up containing a larger sized image.

To recap, Docker containers are created using docker images, built by parsing a Dockerfile containing Docker commands.

“By using containers, resources can be isolated, services restricted, and processes provisioned to have a private view of the operating system with their own process ID space, file system structure, and network interfaces. Multiple containers can share the same kernel, but each container can be constrained to only use a defined amount of resources such as CPU, memory and I/O.” – Wikipedia

Each container runs as an isolated process on a shared kernel. The isolation mechanisms that keeps resources (CPU, memory, filesystem, network, etc.) of each process isolated from others is a Linux kernel feature CGroups (abbreviated from “Control Groups”) developed within Google.

During PyCon on Friday, March 15, 2013. Solomon Hykes, the founder of Docker, gave a lightning talk on “The future of Linux Containers, delivered”.

Alternatives to Docker

boycottdocker.org raises some technical concerns about Docker.

Alternatives to Docker:

CoreOS developed appc with a rkt (pronounced “rocket”) implementation in their Open Containers Initiative (OCI). The runC OS for spawning and running containers is built using Go v1.6+. CoreOS offers a Container Linux distribution, an upstream variant of Red Hat Enterprise Linux from projectatomic.io Atomic Host collection of distributions.

open-source LinuxKit originated from Docker, inc. as a tool for building minimal custom operating systems, to host the Docker platform.
Canonical of Ubuntu has their LXD
Over the years, Kelsey Hightower - has updated his Kubernetes the hard way to use (instead of Docker) CRI-O, containerd, and gvisor. Other options include clearcontainers and katacontainers.
Red Hat created quay.io container registry to compete with DockerHub. But the “other shoe has dropped” when RHEL Enterprise Linux 8 Beta introduces a new Container Tools module which consists of the podman-docker.noarch package to emulate Docker CLI. Other bits include Buildah to build OCI images and Skopeo to copy images.

Linux installer boots

PROTIP: Docker was initially developed to run under different flavors of GNU/Linux, not FreeBSD.

Ubuntu
CentOS
BSDLinux
Debian

docker-filesystems-multilayer 650x534-211kb

Different operating systems use different file-system software for union-mount. For example, Debian uses bootfs. Wikipedia notes aufs (Advanced multi-layered Unification File System) was rejected for merging into mainline Linux. Its code was criticized for being “dense, unreadable, and uncommented”. Instead, OverlayFS was merged into the Linux kernel.

btrfs (B-tree File System) is intended to address the lack of pooling, snapshots, checksums, and integral multi-device spanning in Linux file systems.

Docker Engine-Community only target Docker for AWS and Docker for Azure. Docker Enterprise uses Docker certified infrastructure tooling, using Terraform and Ansible to target VMware, Azure, and AWS implementations.

Setup Shell Script

The contribution of this article is a shell script that automates the install of Wordpress by following the manual steps described below:

https://github.com/wilsonmar/DevSecOps/blob/master/Docker/docker-setup.sh

The “boilerplate” sections at the top of the script is based on my bash coding tutorial.

The script has the following:

To remove all: sudo docker container prune
sudo docker rm

GPG SecureApt

Some scripts, especially those to install unvetted packages, public key it associates with the cryptographic signature it generates for each file so that you can verify whether files have been tampered with or bits lost during transit. Use of GPG (GNU Privacy Guard) or PGP (Pretty Good Privacy) is stronger than MD5 hashes.

With Ansible, see this.

Download Docker’s signature into your Debian local key vault:

# Add Docker's public GPG key :
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
 # OK is the expected response.

The script captures the fingerprint in the response.

To verify the key downloaded, search for the last 8 characters of the signature’s fingerprint (such as “0EBFCD88” below) to ensure it’s same as what the publisher generated:
```
sudo apt-key fingerprint 0EBFCD88
```

Add the stable repository:

sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"

Update the apt package index again according to official site.
```
sudo apt-get update
```
Install the latest version of Docker CE
```
sudo apt-get install docker-ce
```
If a packager does not offer one, skip validation of the signature by specifying RedHat’s yum has –nogpgcheck or Debian’s dpkg –no-debsig. Alternately, edit GPGCHECK=1 to 0. rpm (for MySQL)
We can check the version of the Docker:
```
sudo docker -v
```
Run the hello world image to see whether it is installed successfully:
```
sudo docker run hello-world
```
The response should be “Hello from Docker!”.

https://docs.docker.com/install/linux/docker-ce/ubuntu/

Install Docker on MacOS

PROTIP: The version of Linux that comes with Mac isn’t completely compatible with Linux. So an extra layer is needed to emulate a Docker host. That’s Boot2Docker.

If you’ve previously installed Boot2Docker or Docker for Mac, uninstall it by deleting it within your Applications folder.

https://docs.docker.com/docker-for-mac is the official docs.

Versions of Mac before Yosemite would need to use the now deprecated Docker Toolbox, which is no longer used. It depended on Virtualbox. If Virtualbox version 5.1.2 is installed, it can be left installed. Docs here says VirtualBox prior to version 4.3.30 must NOT be installed (it is incompatible with Docker for Mac).

Alternately, if you have are still running OS X 10.8 Mountain Lion or earlier, install https://www.docker.com/products/docker-toolbox
In Finder, within Applications, remove the Docker app and Docker folder.
Install the Stable version of Homebrew:
```
brew install --cask docker && docker ps
```
If one was already installed, it is replaced:
```
 ==> Downloading https://download.docker.com/mac/stable/19611/Docker.dmg
==> Verifying checksum for Cask docker
==> Installing Cask docker
==> Moving App 'Docker.app' to '/Users/wilsonmar/Applications/Docker.app'.
🍺  docker was successfully installed!
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
```
Skip to Open Docker client app later in this doc.

Alternately:

Manual Docker for Mac

Docker for Mac was added 2016 for installing Docker on Mac OSX. It uses the HyperKit VM (“xhyve”, pronounced “x-hive”) to virtualize the Docker Engine environment. That technology requires OS X 10.10.3 Yosemite or newer.

Go to the page where you download the “Docker Community Edition (CE) Desktop for Mac” at:
https://store.docker.com/editions/community/docker-ce-desktop-mac
Scroll down to “Get Docker CE for Mac (stable)”.
Click “Get Docker for Mac” to download Docker.dmg to your Downloads folder.
In the browser or Finder, navigate to you Download folder to double-click the Docker.dmg file

PROTIP: Change the file name if you’re keeping back versions.

Date of file	Version	Download	Unzipped
Oct 17, 2017	Docker.dmg	133.6 MB	129.9 MB
Aug 27, 2017	Docker.dmg	129.9 MB	129.9 MB
Oct 17, 2016	Docker.dmg	111.0 MB	208.1 MB
July 19, 2016	Docker.dmg	114.0 MB	225.1 MB
July 19, 2016	Docker.dmg	107.0 MB	225.1 MB
June 17, 2016	1.12.0-rc2-beta16	113.5 MB	224.1 MB

If you prefer, navigate in Finder to your Downloads folder to find the Docker.dmg file.
Double-click on Docker.dmg to open it.
In the pop-up, drag and drop the “Docker.app” whale onto the Applications folder.
Click Replace the previous version with the new one, if applicable.
If the “Docker needs privileged access” pop-up appears, click OK and type it in, then dismiss the pop-up.
Click outside the drop-down to dismiss it.

Clean up the installer
Exit the “Drag and Drop” pop-up.
Delete the Docker.dmg file within Finder (to reclaim disk space).
In the Applications folder, under the Devices section on the left, press the eject icon to the right of Docker.

Open Docker client app
In the Applications folder, click on the Docker.app.

PROTIP: The Docker command line stores its configuration files in a hidden directory .docker within your $HOME directory (cd ~).
Click “Open” if the pop-up appears.
Click “Next” at the “Welcome to Docker for Mac!”.
Click “OK” to the “Docker needs privileged access” pop-up.
Provide your password when asked.
Click the whale icon at the top of your Mac for this menu:
PROTIP: If you are not a frequent user, click Preferences (or press command + comma) to un-check “Automatically start Docker when you log in” to avoid using up memory.
Skip to verify Docker install below.

Previously

VIDEO

Obsolete instructions to install using Homebrew cask:

Linux kernel-specific features for the Docker daemon.

Alternately, Docker 0.8 or newer can be run on Macs thanks to a specially developed, lightweight VirtualBox VM.

To start this, use the “quickstart terminal” which fires up Virtualbox.

Install Docker on Windows 10+

My recommendation is to install using Chocolately so you don’t have to click through the https://docs.docker.com/docker-for-windows official installer.

choco install docker-desktop

https://community.chocolatey.org/packages/docker-desktop

Install in Amazon EC2 clouds

Native Windows images have been running within AWS EC2 clouds.

But since Docker images containing Windows OS can run on other machines (such as MacOS and Linux), their use would reduce testing and admin. effort.

The marketing page about run Windows within AWS EC2 is
https://docs.docker.com/machine/examples/aws/

Create an Amazon user account (after using IAM to create it using an Admin account used for billing).
Login to the Console at
https://console.aws.amazon.com/console/home

Using the Amazone CLI:
Create ~/.aws/credentials file based on keys copied during user creation in AWS IAM, such as:
```
[default]
aws_access_key_id = AKID1234567890
aws_secret_access_key = MY-SECRET-KEY
```
This is so you don’t need to specify the keys in the command line:
--amazonec2-access-key AKI******* --amazonec2-secret-key 8T93C*******
In AWS, create an EC2 instance named “aws-sandbox”
```
docker-machine create --driver amazonec2 --amazonec2-region us-west-1 aws-sandbox
 --volumes-from ?
```
“amazonec2” is the driver name for Amazon EC2. Alternatives are
“digitalocean” (with --digitalocean-access-token=) and
“azure” (with --azure-subscription-id).

--volumes-from is how data volumes are associated (for sharing).

*

Install local Windows 10

CAUTION: A 64-bit Windows machine is necessary to run Docker. Not 32-bit.

Enable Microsoft Hyper-V necessary to run Docker for Windows.

CAUTION: This renders ususable Oracle Virtual Box VMs running Docker Toolbox.
Upgrade Windows 10 to at least the “Anniversary Update” 1607 (KB3194798) released October 11, 2016 or more recent.

See the video.

In Settings > Updates & Security > Windows Update > Update & Security > Check for Updates > Update.

Chocolatey
The easiest approach is to use Docker on Chocolately.org
```
choco install -y docker
```
Ignore the installer “docker-machine”. It’s for an older version of Docker.
Skip to verify Docker install.

Manual install

Alternately, at https://docs.docker.com/docker-for-windows,
Click “Get Docker for Windows (stable)” (not the more volatile Beta).
This downloads InstallDocker.msi (105 MB), typically to your account’s Downloads folder.
Right-click file InstallDocker.msi to run (not just Save) the installer as Administrator.
Follow the install wizard to accept the license, authorize the installer, and proceed with the install.
Authorize Docker.app with your system password when prompted, since privileged access is needed to install networking components, links to the Docker apps, and manage the Hyper-V VMs.
Click Finish on the setup complete dialog to launch Docker.

Modules are installed.
Skip to verify Docker install.

Default folders

The default NGINX configuration root directory
- /usr/share/nginx/html is the root directory
- /etc/nginx contains configuration files
To remap configuration files to a different location, specify that first:
```
-v /var/nginx/conf:/etc/nginx:ro
```

Alpine Linux

Within Docker for Mac, the Docker engine runs in an Alpine Linux distribution on top of a Mac xhyve (pronounced “x-hive”) Virtual Machine.

Alpine comes with Docker for Mac, but for additional information, see:

https://alpinelinux.org

File Date	Download	Type	Size MB
2016-09-28	alpine-virt-3.4.4-x86_64.iso	Virtual	39 MB
2016-09-28	alpine-3.4.4-x86_64.iso	Standard	85 MB
2016-09-28	alpine-extended-3.4.4-x86_64.iso	Extended	311 MB

BTW, The Alpine Linux distribution (distro) is so small that there is an edition of it for the Raspberry Pi.

Install Docker in CentOS

There are two methods for installing Docker on CentOS 7:

Installing Docker on an existing installation of the operating system.
Spin up a server with Docker Machine which auto-installs Docker.

NOTE: Docker Cloud supercedes Docker Machine.

See https://docs.docker.com/machine/reference/ls/

The Docker installation package available in the official CentOS 7 repository may not be the latest version.

To get the latest and greatest version, install Docker from the official Docker repository.

First, update the package database:

sudo yum check-update

The response:

Failed to set locale, defaulting to C
Loaded plug-ins: fastestmirror
Loading mirror speeds from cached hostfile
        * base: mirror.n5tech.com
        * extras: mirror.pac-12.org
        * updates: mirror.math.princeton.edu

Add the official Docker repository, download the latest version of Docker, and install it:

curl -fsSL https://get.docker.com/ | sh

The response:

+ sh -c 'sleep 3; yum -y -q install docker-engine'
Failed to set locale, defaulting to C
warning: /var/cache/yum/x86_64/7/docker-main-repo/packages/docker-engine-selinux-1.11.2-1.el7.centos.noarch.rpm: Header V4 RSA/SHA512 Signature, key ID 2c52609d: NOKEY
Public key for docker-engine-selinux-1.11.2-1.el7.centos.noarch.rpm is not installed
Importing GPG key 0x2C52609D:
 Userid     : "Docker Release Tool (releasedocker) <docker@docker.com>"
 Fingerprint: 5811 8e89 f3a9 1289 7c07 0adb f762 2157 2c52 609d
 From       : https://yum.dockerproject.org/gpg
setsebool:  SELinux is disabled.
libsemanage.semanage_exec_prog: Child process /sbin/setfiles did not exit cleanly.
libsemanage.semanage_install_active: setfiles returned error code -1.
libsemanage.semanage_exec_prog: Child process /sbin/setfiles did not exit cleanly.
libsemanage.semanage_install_active: setfiles returned error code -1.
/usr/sbin/semodule:  Failed!
 
If you would like to use Docker as a non-root user, you should now consider
adding your user to the "docker" group with something like:
 
  sudo usermod -aG docker your-user
 
Remember that you will have to log out and back in for this to take effect!

With installation complete, start the Docker daemon:
```
sudo systemctl start docker
```
No response is returned.

NOTE: By default, docker commands require root privileges. So commands need to be prefixed with Linux sudo.

Verify it’s running:

sudo systemctl status docker -l

The response:

The output should be similar to the following, showing that the service is active and running:

● docker.service - Docker Application Container Engine
Loaded: loaded (/usr/lib/systemd/system/docker.service; disabled; vendor preset: disabled)
Active: active (running) since Wed 2016-07-27 22:37:40 UTC; 1min 10s ago
  Docs: https://docs.docker.com
 Main PID: 3158 (docker)
Memory: 16.3M
CGroup: /system.slice/docker.service
        ├─3158 /usr/bin/docker daemon -H fd://
        └─3161 docker-containerd -l /var/run/docker/libcontainerd/docker-containerd.sock --runtime docker-runc --start-timeout 2m
 
Jul 27 22:37:40 centos-512mb-sfo2-01 docker[3158]: time="2016-07-27T22:37:40.656780521Z" level=warning msg="Running modprobe bridge br_netfilter failed with message: modprobe: WARNING: Module br_netfilter not found.\ninsmod /lib/modules/3.10.0-327.22.2.el7.x86_64/kernel/net/llc/llc.ko \ninsmod /lib/modules/3.10.0-327.22.2.el7.x86_64/kernel/net/802/stp.ko \ninsmod /lib/modules/3.10.0-327.22.2.el7.x86_64/kernel/net/bridge/bridge.ko \n, error: exit status 1"
Jul 27 22:37:40 centos-512mb-sfo2-01 docker[3158]: time="2016-07-27T22:37:40.673905283Z" level=info msg="Firewalld running: false"
Jul 27 22:37:40 centos-512mb-sfo2-01 docker[3158]: time="2016-07-27T22:37:40.749552123Z" level=info msg="Default bridge (docker0) is assigned with an IP address 172.17.0.0/16. Daemon option --bip can be used to set a preferred IP address"
Jul 27 22:37:40 centos-512mb-sfo2-01 docker[3158]: time="2016-07-27T22:37:40.812028054Z" level=warning msg="mountpoint for pids not found"
Jul 27 22:37:40 centos-512mb-sfo2-01 docker[3158]: time="2016-07-27T22:37:40.812680271Z" level=info msg="Loading containers: start."
Jul 27 22:37:40 centos-512mb-sfo2-01 docker[3158]: time="2016-07-27T22:37:40.812815226Z" level=info msg="Loading containers: done."
Jul 27 22:37:40 centos-512mb-sfo2-01 docker[3158]: time="2016-07-27T22:37:40.812841211Z" level=info msg="Daemon has completed initialization"
Jul 27 22:37:40 centos-512mb-sfo2-01 docker[3158]: time="2016-07-27T22:37:40.812872955Z" level=info msg="Docker daemon" commit=b9f10c9 graphdriver=devicemapper version=1.11.2
Jul 27 22:37:40 centos-512mb-sfo2-01 docker[3158]: time="2016-07-27T22:37:40.850984219Z" level=info msg="API listen on /var/run/docker.sock"
Jul 27 22:37:40 centos-512mb-sfo2-01 systemd[1]: Started Docker Application Container Engine.

Configure to git it to start at every server reboot:
```
sudo systemctl enable docker
```
NOTE: This only needs to be done once per instance.

The response:

Created symlink from /etc/systemd/system/multi-user.target.wants/docker.service to /usr/lib/systemd/system/docker.service.
Skip to verify Docker install.

Install Docker on Windows 10

Upgrade your Windows 10 to the Anniversary Edition update or later.
Download “Docker for Windows”

https://www.docker.com/docker-windows

NOTE: Do not download the Beta (as of September 2016) https://download.docker.com/win/beta/InstallDocker.msi as mentioned in https://stefanscherer.github.io/run-linux-and-windows-containers-on-windows-10/ and https://blog.docker.com/2016/09/build-your-first-docker-windows-server-container/
https://docs.docker.com/docker-for-windows/
Skip to verify Docker install below.
Spin up a standard AWS Linux 2 EC2 instance.


sudo yum update -y
sudo amazon-linux-extras install docker
sudo service docker start

Add the ec2-user to the docker group so you can execute Docker commands without using sudo:
```
sudo usermod -a -G docker ec2-user
```
Log out and log back into your EC2 instance so ec2-user can assume the new permissions.
Verify the ec2-user can run Docker commands without sudo:
```
docker info
```
Skip to verify Docker install below.

These instructions apply to Docker running within all operating systems.

Open a Terminal shell window.

After Docker installation, the same Docker commands are applicable on all operating systems:

PROTIP: Some Docker commands work without the Docker daemon running.

List all docker command options:

docker

The response:

Usage:   docker COMMAND
 
A self-sufficient runtime for containers
 
Options:
 
  --config=~/.docker              Location of client config files
  -D, --debug                     Enable debug mode
  -H, --host=[]                   Daemon socket(s) to connect to
  -h, --help                      Print usage
  -l, --log-level=info            Set the logging level
  --tls                           Use TLS; implied by --tlsverify
  --tlscacert=~/.docker/ca.pem    Trust certs signed only by this CA
  --tlscert=~/.docker/cert.pem    Path to TLS certificate file
  --tlskey=~/.docker/key.pem      Path to TLS key file
  --tlsverify                     Use TLS and verify the remote
  -v, --version                   Print version information and quit
 
Commands:
 attach    Attach to a running container
 build     Build an image from a Dockerfile
 commit    Create a new image from a container's changes
 cp        Copy files/folders between a container and the local filesystem
 create    Create a new container
 deploy    Create and update a stack from a Distributed Application Bundle (DAB)
 diff      Inspect changes on a container's filesystem
 events    Get real time events from the server
 exec      Run a command in a running container
 export    Export a container's filesystem as a tar archive
 history   Show the history of an image
 images    List images
 import    Import the contents from a tarball to create a filesystem image
 info      Display system-wide information
 inspect   Return low-level information on a container, image or task
 kill      Kill one or more running container
 load      Load an image from a tar archive or STDIN
 login     Log in to a Docker registry.
 logout    Log out from a Docker registry.
 logs      Fetch the logs of a container
 network   Manage Docker networks
 node      Manage Docker Swarm nodes
 pause     Pause all processes within one or more containers
 plugin    Manage Docker plugins
 port      List port mappings or a specific mapping for the container
 ps        List containers
 pull      Pull an image or a repository from a registry
 push      Push an image or a repository to a registry
 rename    Rename a container
 restart   Restart a container
 rm        Remove one or more containers
 rmi       Remove one or more images
 run       Run a command in a new container
 save      Save one or more images to a tar archive (streamed to STDOUT by default)
 search    Search the Docker Hub for images
 service   Manage Docker services
 stack     Manage Docker stacks
 start     Start one or more stopped containers
 stats     Display a live stream of container(s) resource usage statistics
 stop      Stop one or more running containers
 swarm     Manage Docker Swarm
 tag       Tag an image into a repository
 top       Display the running processes of a container
 unpause   Unpause all processes within one or more containers
 update    Update configuration of one or more containers
 version   Show the Docker version information
 volume    Manage Docker volumes
 wait      Block until a container stops, then print its exit code
 
Run 'docker COMMAND --help' for more information on a command.

Get Docker version property using either the short or long form of parameter:
```
docker \-\-version
```
The response:
```
Docker version 17.09.0-ce, build afdb6d4
```
The “experimental” in previous versions has been removed.

Obtain the version number using a sub-command:

docker version

Sample response on the Mac:

Client:
 Version:      17.09.0-ce
 API version:  1.32
 Go version:   go1.8.3
 Git commit:   afdb6d4
 Built:        Tue Sep 26 22:40:09 2017
 OS/Arch:      darwin/amd64
 
Server:
 Version:      17.09.0-ce
 API version:  1.32 (minimum version 1.12)
 Go version:   go1.8.3
 Git commit:   afdb6d4
 Built:        Tue Sep 26 22:45:38 2017
 OS/Arch:      linux/amd64
 Experimental: true

Sample response on Centos:

Client:
 Version:      1.11.2
 API version:  1.23
 Go version:   go1.5.4
 Git commit:   b9f10c9
 Built:        Wed Jun  1 21:23:11 2016
 OS/Arch:      linux/amd64
 
Server:
 Version:      1.11.2
 API version:  1.23
 Go version:   go1.5.4
 Git commit:   b9f10c9
 Built:        Wed Jun  1 21:23:11 2016
 OS/Arch:      linux/amd64

Sample response on Windows:

Client:
Version:      1.12.0
API version:  1.24
Go version:   go1.6.3
Git commit:   8eab29e
Built:        Thu Jul 28 21:04:48 2016
OS/Arch:      windows/amd64
Experimental: true
 
Server:
Version:      1.12.0
API version:  1.24
Go version:   go1.6.3
Git commit:   8eab29e
Built:        Thu Jul 28 21:04:48 2016
OS/Arch:      linux/amd64
Experimental: true

PROTIP: A Windows Server Docker image runs within a Linux Docker instance on a Windows 10 machine. Strange but true because Docker makes use of Linux drivers.

Full Docker Info

PROTIP: The most detailed status is obtained using the info sub-command, which requires the docker daemon to be running.

docker info

An example of command output for docker info on Windows:

Containers: 0
 Running: 0
 Paused: 0
 Stopped: 0
Images: 0
Server Version: 17.09.0-ce
Storage Driver: overlay2
 Backing Filesystem: extfs
 Supports d_type: true
 Native Overlay Diff: true
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins:
 Volume: local
 Network: bridge host ipvlan macvlan null overlay
 Log: awslogs fluentd gcplogs gelf journald json-file logentries splunk syslog
Swarm: inactive
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version: 06b9cb35161009dcb7123345749fef02f7cea8e0
runc version: 3f2f8b84a77f73d38244dd690525642a72156c64
init version: 949e6fa
Security Options:
 seccomp
  Profile: default
Kernel Version: 4.9.49-moby
Operating System: Alpine Linux v3.5
OSType: linux
Architecture: x86_64
CPUs: 4
Total Memory: 1.952GiB
Name: moby
ID: JCZB:QL6G:SWXG:GURD:53OL:57EY:WNDW:QDHX:GDPD:H3G7:PGU7:45HU
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): true
 File Descriptors: 18
 Goroutines: 29
 System Time: 2017-10-17T22:22:38.984450422Z
 EventsListeners: 1
No Proxy: *.local, 169.254/16
Registry: https://index.docker.io/v1/
Experimental: true
Insecure Registries:
 127.0.0.0/8
Live Restore Enabled: false

Container Registries

Amazon ECR (EC2 Container Registry) is designed to serve requests within AWS, at lower latency than external registries. ECR does not yet support vulnerability scanning.
GCR (Google Container Registry)
ACR (Azure Container Registry) supports all kinds of containers, including Mesosphere. Azure manages network latency by leveraging its vast cloud computing network so that the closest clusters are used. Good for use with Azure Kubernetes Service (AKS).
GitLab a container registry?
JFrog Artifactory

G2 in 2019 gave these crowd-sourced ratings:
dockerhub-competitors-613x540-21197

Not in their analysis are:

quay.io container registry Red Hat (now IBM) created to compete with DockerHub by providing enterprise features such as vulnerability scanning. Its RHEL Enterprise Linux 8 Beta introduces a new Container Tools module to replace Docker.

Setup Docker Hub

https://hub.docker.com
If you don’t have a Docker account already, Sign-up for an account and click the “Confirm your email” button in the email with subject “Please confirm email for your Docker ID‏”.
Link Docker Hub to your GitHub account. Click on your photo at the upper right. Select Settings, “Linked Accounts & Services”.

If you’re already linked, an “Unlink” appears. Proceeding as if there isn’t.
CAUTION: Selecting “Public and Private” means Docker can see ALL your private repositories.

PROTIP: Open a another set of GitHub and Docker accounts based on another email account to work only with public-facing repos for this exercise.
At the top menu, pull down the Create menu to select “Create Automated Build”. Click the Github button.

NOTE: The above is covered by a segment in this Pluralsight video.
Click on the repo.
Type in a short description and click Create.
Under the “Docker Pull Command” at the right pane, for example:
```
docker pull wilsonmar/99bottles-jmeter
```
Notice that, to Dockerhub, “target” isn’t a URL but an account name.

Copy and paste the command above.

The response if you’re in the right folder for Docker:

Using default tag: latest
Pulling repository docker.io/wilsonmar/99bottles-jmeter
Tag latest not found in repository docker.io/wilsonmar/99bottles-jmeter

List and remove image

List images pulled:

docker images -a -q

A sample response:

REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
jenkins/jenkins     latest              9ec0e1781a1b        41 hours ago        815MB
nginx               latest              1e5ab59102ce        8 days ago          108MB

Remove all images pulled, to save disk space:
```
docker rmi $(docker images -a -q)
```
Remove a list of dangling images:
```
docker rmi $(docker images -f dangling=true -q)
```
Setup Credential Store

https://github.com/docker/docker-credential-helpers/releases
Click the latest “osxkeychain”:

docker-credential-osxkeychain-v0.6.0-amd64.tar.gz
In Finder, double-click to expand the file
Move to within a $PATH:
```
cd ~/Downloads
mv docker-credential-osxkeychain /usr/local/bin
chmod 555 /usr/local/bin/docker-credential-osxkeychain
```
CAUTION: The credential helper is used whenever it is discovered on $PATH, not only if config.json “credsStore” value declares it.
Open Apple’s Keychain Access.app within Applications Utilities.
Store your Docker credentials:
```
docker-credential-osxkeychain store
```
Log into Docker Hub

https://cloud.google.com/container-registry/docs/advanced-authentication

https://github.com/docker/cli/blob/master/docs/reference/commandline/login.md
Login using your Docker:

The response:
```
WARNING! Using --password via the CLI is insecure. Use --password-stdin.
```
PROTIP: Using STDIN prevents the password from ending up in the shell’s history and log files.
PROTIP: At your home folder create a .secrets file containing set statements:
```
cd 
echo set >.secrets
```

Edit the text file to contain the username and password you setup at https://hub.docker.com/ for example:


export DOCKER_USERNAME=wilsonmar
export DOCKER_PASSWORD=12345abcde7890jl;k
echo $DOCKER_USERNAME
echo "$DOCKER_PASSWORD" | docker login -u "$DOCKER_USERNAME" --password-stdin -e none

Run the file:
```
source .secrets
```
You should see your user name reflected.

Alternately, supply the authentication information in the command (replacing ** with your own):
```
docker login -u "$DOCKER_USERNAME" -p "$DOCKER_PASSWORD"
```
(The –email flag was required by Docker older that 1.11)

PROTIP: TODO: Advanced users create a .dockercfg file.

The successful response is:
```
WARNING: login credentials saved in C:\Users\...\\.docker\config.json
```
When Docker is installed, it creates a .docker folder at your account root folder. It contains files daemon.json and ~/.docker/config.json:
```
{
  "auths" : {
 "https://index.docker.io/v1/" : {
      "auth": "YW11cmRhY2E6c3VwZXJzZWNyZXRwYXNzd29yZA==",
      "email": "amurdaca@redhat.com"
  }
  },
  "credsStore" : "osxkeychain"
}
```
On Linux, the credsStore is populated with the string secretservice.

PROTIP: Other auths can be added.

After a successful Docker login, Docker stores a base64 encoded string from the concatenation of the username, a colon, and the password and associates this string to the registry the user is logging into file ...\myuser.docker\config.json

The trouble with this is that it’s encrypted. The base64 string can be converted back to clear ASCII text:
```
echo YW11cmRhY2E6c3VwZXJzZWNyZXRwYXNzd29yZA== | base64 -d -
```

The authentication information is removed upon:

docker logout

The response is about cat ~/.docker/config.json

Removing login credentials for https://index.docker.io/v1/

which would avoid the following error later:

docker: Error response from daemon: Get https://registry-1.docker.io/v2/library/hello-world/manifests/latest: unauthorized: incorrect username or password.

However, if you are not setup correctly, you’ll see:

Warning: failed to get default registry endpoint from daemon (Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?). Using system default: https://index.docker.io/v1/
Login with your Docker ID to push and pull images from Docker Hub. If you don't have a Docker ID, head over to https://hub.docker.com to create one.

Error response from daemon: Get https://registry-1.docker.io/v2/: unauthorized: incorrect username or password

Troubleshoot Docker daemon start

If you also see this message:

Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

Use Linux operating system commands to see whether it starts up. On Linux:

/etc/systemd/system/docker.service
```
systemctl status docker.service
```
For detail:
```
journalctl -u docker.service
```
On ubuntu server, restart:

sudo shutdown -r now

$ systemctl daemon-reload

$ sudo service docker restart

$ sudo service docker status (should see active (running))

To start:
```
systemctl start docker
```

Modules installed

Installing Docker gives you not just the Docker service (daemon) but also the docker command line utility, or the Docker client.

Regardless of the OS, the installation provides:

Docker Machine
Docker CLI client
Docker Engine
Docker Compose
Docker Swarm

See the list of supported drivers at
https://docs.docker.com/machine/drivers
PROTIP: There’s a different version of each Docker module:
```
docker-compose \-\-version
```
A sample response:
```
docker-compose version 1.14.0, build c7bdf9e
```
PROTIP: There’s a different version of each Docker module:
```
docker-machine \-\-version
```
A sample response:
```
docker-machine version 0.12.0, build 45c69ad
```

Set Maximum File Descriptors

The vm_max_map_count kernel setting needs to be set to at least 262144 for production use. Depending on your platform:

On Linux:

Edit file /etc/sysctl.conf

grep vm.max_map_count /etc/sysctl.conf
 vm.max_map_count=262144

The above sets permanently.

To apply the setting on a live system type:

sysctl -w vm.max_map_count=262144

OSX with Docker for Mac

The vm_max_map_count setting must be set within the xhyve virtual machine:

screen ~/Library/Containers/com.docker.docker/Data/com.docker.driver.amd64-linux/tty

sysctl -w vm.max_map_count=262144

MacOS with Docker Toolbox:

The vm_max_map_count setting must be set via docker-machine:

docker-machine ssh

   sudo sysctl -w vm.max_map_count=262144

Run from Docker Hub

PROTIP: Similar to Python, most people run commands within a Docker machine (which is the whole point of installing Docker).

From https://docs.docker.com/v1.8/introduction/understanding-docker/

docker-flow-505x264-37904

This section describes how to run a Docker image.

You need to be logged into Docker Hub.

To verify whether you can access a simple image:

docker run hello-world


Like Maven Central, 
a Docker run command automatically pulls from the public Docker Repository, 
such as:


https://hub.docker.com/_/hello-world

It's defined at

https://github.com/docker-library/hello-world

with docs at

https://github.com/docker-library/docs/tree/master/hello-world

If the image is not available locally, it is pulled from Dockerhub:

Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
c04b14da8d14: Pull complete 
Digest: sha256:0256e8a36e2070f7bf2d0b0763dbabdd67798512411de4cdcf9431a1feb60fd9
Status: Downloaded newer image for hello-world:latest


The expected response is:

Hello from Docker!
This message shows that your installation appears to be working correctly.
 
To generate this message, Docker took the following steps:

The Docker client contacted the Docker daemon.
The Docker daemon pulled the “hello-world” image from the Docker Hub.
The Docker daemon created a new container from that image which runs the executable that produces the output you are currently reading.
The Docker daemon streamed that output to the Docker client, which sent it to your terminal. To try something more ambitious, you can run an Ubuntu container with: $ docker run -it ubuntu bash Share images, automate workflows, and more with a free Docker Hub account: https://hub.docker.com

</pre>

Run the container just downloaded in a Mac:

docker run -it ubuntu bash

PROTIP: Mac uses Ubuntu commands.

The response:

Unable to find image 'ubuntu:latest' locally
latest: Pulling from library/ubuntu
43db9dbdcb30: Pull complete 
2dc64e8f8d4f: Pull complete 
670a583e1b50: Pull complete 
183b0bfcd10e: Pull complete 
Digest: sha256:c6674c44c6439673bf56536c1a15916639c47ea04c3d6296c5df938add67b54b
Status: Downloaded newer image for ubuntu:latest
root@27eb89b0dc54:

Wait for “Pull complete” for all the dependencies.

Alternately, on a CentOS machine:

docker run -it centos bash

The response:

Unable to find image 'centos:latest' locally
latest: Pulling from library/centos
8c3d77a518cb: Pull complete 
Digest: sha256:7b754086d2c7d74ac39dc0a2545d7b06d4266f873d502feb5b3e8bfca27c5dd8
Status: Downloaded newer image for centos:latest

WARNING: The terminal prompt has changed because you are now inside the container.

Docker Help

-it means iteractive and TTY, which provides you the terminal prompt.

Get a list of all the docker run command parameters:

docker run \-\-help

Usage:   docker run [OPTIONS] IMAGE [COMMAND] [ARG...]
 
Run a command in a new container
 
Options:
   --add-host list                  Add a custom host-to-IP mapping (host:ip)
  -a, --attach list                    Attach to STDIN, STDOUT or STDERR
   --blkio-weight uint16            Block IO (relative weight), between 10 and 1000, or 0 to
                                    disable (default 0)
   --blkio-weight-device list       Block IO weight (relative device weight) (default [])
   --cap-add list                   Add Linux capabilities
   --cap-drop list                  Drop Linux capabilities
   --cgroup-parent string           Optional parent cgroup for the container
   --cidfile string                 Write the container ID to the file
   --cpu-count int                  CPU count (Windows only)
   --cpu-percent int                CPU percent (Windows only)
   --cpu-period int                 Limit CPU CFS (Completely Fair Scheduler) period
   --cpu-quota int                  Limit CPU CFS (Completely Fair Scheduler) quota
   --cpu-rt-period int              Limit CPU real-time period in microseconds
   --cpu-rt-runtime int             Limit CPU real-time runtime in microseconds
  -c, --cpu-shares int                 CPU shares (relative weight)
   --cpus decimal                   Number of CPUs
   --cpuset-cpus string             CPUs in which to allow execution (0-3, 0,1)
   --cpuset-mems string             MEMs in which to allow execution (0-3, 0,1)
  -d, --detach                         Run container in background and print container ID
   --detach-keys string             Override the key sequence for detaching a container
   --device list                    Add a host device to the container
   --device-cgroup-rule list        Add a rule to the cgroup allowed devices list
   --device-read-bps list           Limit read rate (bytes per second) from a device (default [])
   --device-read-iops list          Limit read rate (IO per second) from a device (default [])
   --device-write-bps list          Limit write rate (bytes per second) to a device (default [])
   --device-write-iops list         Limit write rate (IO per second) to a device (default [])
   --disable-content-trust          Skip image verification (default true)
   --dns list                       Set custom DNS servers
   --dns-option list                Set DNS options
   --dns-search list                Set custom DNS search domains
   --entrypoint string              Overwrite the default ENTRYPOINT of the image
  -e, --env list                       Set environment variables
   --env-file list                  Read in a file of environment variables
   --expose list                    Expose a port or a range of ports
   --group-add list                 Add additional groups to join
   --health-cmd string              Command to run to check health
   --health-interval duration       Time between running the check (ms|s|m|h) (default 0s)
   --health-retries int             Consecutive failures needed to report unhealthy
   --health-start-period duration   Start period for the container to initialize before starting
                                    health-retries countdown (ms|s|m|h) (default 0s)
   --health-timeout duration        Maximum time to allow one check to run (ms|s|m|h) (default 0s)
   --help                           Print usage
  -h, --hostname string                Container host name
   --init                           Run an init inside the container that forwards signals and
                                    reaps processes
  -i, --interactive                    Keep STDIN open even if not attached
   --io-maxbandwidth bytes          Maximum IO bandwidth limit for the system drive (Windows only)
   --io-maxiops uint                Maximum IOps limit for the system drive (Windows only)
   --ip string                      IPv4 address (e.g., 172.30.100.104)
   --ip6 string                     IPv6 address (e.g., 2001:db8::33)
   --ipc string                     IPC namespace to use
   --isolation string               Container isolation technology
   --kernel-memory bytes            Kernel memory limit
  -l, --label list                     Set meta data on a container
   --label-file list                Read in a line delimited file of labels
   --link list                      Add link to another container
   --link-local-ip list             Container IPv4/IPv6 link-local addresses
   --log-driver string              Logging driver for the container
   --log-opt list                   Log driver options
   --mac-address string             Container MAC address (e.g., 92:d0:c6:0a:29:33)
  -m, --memory bytes                   Memory limit
   --memory-reservation bytes       Memory soft limit
   --memory-swap bytes              Swap limit equal to memory plus swap: '-1' to enable unlimited swap
   --memory-swappiness int          Tune container memory swappiness (0 to 100) (default -1)
   --mount mount                    Attach a filesystem mount to the container
   --name string                    Assign a name to the container
   --network string                 Connect a container to a network (default "default")
   --network-alias list             Add network-scoped alias for the container
   --no-healthcheck                 Disable any container-specified HEALTHCHECK
   --oom-kill-disable               Disable OOM Killer
   --oom-score-adj int              Tune host's OOM preferences (-1000 to 1000)
   --pid string                     PID namespace to use
   --pids-limit int                 Tune container pids limit (set -1 for unlimited)
   --privileged                     Give extended privileges to this container
  -p, --publish list                   Publish a container's port(s) to the host
  -P, --publish-all                    Publish all exposed ports to random ports
   --read-only                      Mount the container's root filesystem as read only
   --restart string                 Restart policy to apply when a container exits (default "no")
   --rm                             Automatically remove the container when it exits
   --runtime string                 Runtime to use for this container
   --security-opt list              Security Options
   --shm-size bytes                 Size of /dev/shm
   --sig-proxy                      Proxy received signals to the process (default true)
   --stop-signal string             Signal to stop a container (default "SIGTERM")
   --stop-timeout int               Timeout (in seconds) to stop a container
   --storage-opt list               Storage driver options for the container
   --sysctl map                     Sysctl options (default map[])
   --tmpfs list                     Mount a tmpfs directory
  -t, --tty                            Allocate a pseudo-TTY
   --ulimit ulimit                  Ulimit options (default [])
  -u, --user string                    Username or UID (format: <name|uid>[:<group|gid>])
   --userns string                  User namespace to use
   --uts string                     UTS namespace to use
  -v, --volume list                    Bind mount a volume
   --volume-driver string           Optional volume driver for the container
   --volumes-from list              Mount volumes from the specified container(s)
  -w, --workdir string                 Working directory inside the container

Docker terminal inside the container

Make sure the Docker process can run by getting a Terminal inside the container:

docker exec -it test ps aux

Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

docker: Cannot connect to the Docker daemon. Is the docker daemon running on this host?.
See 'docker run --help'.

BLAH: If you are running this within a corporate firewall, you may need to obtain permissions and/or specify client network settings.

Docker pull

To bring the Dockerfile local without running it also:

docker pull library/hello-world

A sample response:

Using default tag: latest
latest: Pulling from library/hello-world
b04784fba78d: Pull complete 
Digest: sha256:f3b3b28a45160805bb16542c9531888519430e9e6d6ffc09d72261b0d26ff74f
Status: Downloaded newer image for hello-world:latest

List images downloaded locally:
```
docker images
```
The response:
```
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
centos              latest              50dae1ee8677        8 days ago          196.7 MB
hello-world         latest              c54a2cc56cbb        3 weeks ago         1.848 kB
node                0.10.44-slim        f73347dab179        12 weeks ago        192.6 MB
```
The “centos” image contains CentOS with no apps installed.

The “node” image contains CenOS with Node installed, but no custom Node apps.

PROTIP: You won’t find Docker images on your local folder. See Where are docker images stored?

See https://www.digitalocean.com/community/tutorials/how-to-install-and-use-docker-on-centos-7
Turn your Wi-Fi off.
Run it again from your local cache using the default “library” user, so the command is equivalent to:
```
docker run library/hello-world
```

Dockviz

PROTIP: Consider a third-party tool to display visualizations of image data: dockviz presents Docker image and container information in graphic form to help you understand what’s going on inside the system.

ImageLayers.io is an Adobe Flash site that shows how each command in Dockerfile contributes to the final Docker image, and discover which layers are shared by multiple images. It presents an ImageLayers badge about the size of an image, and how many layers it is composed of.

Base DockerHub Search

See the Officially supported repositories at:
https://hub.docker.com/explore

They include:

operating systems (ubuntu, centos)
database server base (redis, mongo, mysql, postgres, elasticsearch)
app server base (node, nginx, httpd)
blog app server base (wordpress, alpine)

Windows Insider Images

Before pulling Microsoft’s images from https://hub.docker.com/u/microsoft/ note they are designed to be used from “Windows Insider program” Windows Server or Windows 10 Container hosts. They are of “beta” quality.

docker pull microsoft/windowsservercore-insider

Ubuntu search

Search for Ubuntu images on the free and public repository at
https://hub.docker.com

docker search ubuntu

The response (27 Jul 2016):

NAME                              DESCRIPTION                                     STARS     OFFICIAL   AUTOMATED
ubuntu                            Ubuntu is a Debian-based Linux operating s...   4343      [OK]       
ubuntu-upstart                    Upstart is an event-based replacement for ...   65        [OK]       
rastasheep/ubuntu-sshd            Dockerized SSH service, built on top of of...   30                   [OK]
torusware/speedus-ubuntu          Always updated official Ubuntu docker imag...   26                   [OK]
ubuntu-debootstrap                debootstrap --variant=minbase --components...   25        [OK]       
nickistre/ubuntu-lamp             LAMP server on Ubuntu                           8                    [OK]
nuagebec/ubuntu                   Simple always updated Ubuntu docker images...   6                    [OK]
nickistre/ubuntu-lamp-wordpress   LAMP on Ubuntu with wp-cli installed            6                    [OK]
nimmis/ubuntu                     This is a docker images different LTS vers...   5                    [OK]
maxexcloo/ubuntu                  Docker base image built on Ubuntu with Sup...   2                    [OK]
admiringworm/ubuntu               Base ubuntu images based on the official u...   1                    [OK]
darksheer/ubuntu                  Base Ubuntu Image -- Updated hourly             1                    [OK]
jordi/ubuntu                      Ubunt
u Base Image                               1                    [OK]
esycat/ubuntu                     Ubuntu LTS                                      0                    [OK]
datenbetrieb/ubuntu               custom flavor of the official ubuntu base ...   0                    [OK]
life360/ubuntu                    Ubuntu is a Debian-based Linux operating s...   0                    [OK]
konstruktoid/ubuntu               Ubuntu base image                               0                    [OK]
widerplan/ubuntu                  Our basic Ubuntu images.                        0                    [OK]
croscon/ubuntu                    Crosconized Ubuntu                              0                    [OK]
teamrock/ubuntu                   TeamRock's Ubuntu image configured with AW...   0                    [OK]
ustclug/ubuntu                    ubuntu image for docker with USTC mirror        0                    [OK]
smartentry/ubuntu                 ubuntu with smartentry                          0                    [OK]
dorapro/ubuntu                    ubuntu image                                    0                    [OK]
lynxtp/ubuntu                     https://github.com/lynxtp/docker-ubuntu         0                    [OK]
webhippie/ubuntu                  Docker images for ubuntu                        0                    [OK]

Widen the Terminal window so lines don’t wrap.

Search for centos images on the free and public repository at
https://hub.docker.com

docker search centos

The response (27 Jul 2016):

NAME                          DESCRIPTION                                     STARS     OFFICIAL   AUTOMATED
centos                        The official build of CentOS.                   2475      [OK]       
jdeathe/centos-ssh            CentOS-6 6.8 x86_64 / CentOS-7 7.2.1511 x8...   26                   [OK]
nimmis/java-centos            This is docker images of CentOS 7 with dif...   13                   [OK]
million12/centos-supervisor   Base CentOS-7 with supervisord launcher, h...   12                   [OK]
consol/centos-xfce-vnc        Centos container with "headless" VNC sessi...   10                   [OK]
torusware/speedus-centos      Always updated official CentOS docker imag...   8                    [OK]
nickistre/centos-lamp         LAMP on centos setup                            4                    [OK]
centos/mariadb55-centos7                                                      3                    [OK]
nathonfowlie/centos-jre       Latest CentOS image with the JRE pre-insta...   3                    [OK]
consol/sakuli-centos-xfce     Sakuli end-2-end testing and monitoring co...   2                    [OK]
timhughes/centos              Centos with systemd installed and running       1                    [OK]
darksheer/centos              Base Centos Image -- Updated hourly             1                    [OK]
blacklabelops/centos          CentOS Base Image! Built and Updates Daily!     1                    [OK]
ericuni/centos                centos dev                                      0                    [OK]
kz8s/centos                   Official CentOS plus epel-release               0                    [OK]
grossws/centos                CentOS 6 and 7 base images with gosu and l...   0                    [OK]
harisekhon/centos-scala       Scala + CentOS (OpenJDK tags 2.10-jre7 - 2...   0                    [OK]
grayzone/centos               auto build for centos.                          0                    [OK]
aguamala/centos               CentOS base image                               0                    [OK]
dmglab/centos                 CentOS with some extras - This is for the ...   0                    [OK]
jsmigel/centos-epel           Docker base image of CentOS w/ EPEL installed   0                    [OK]
januswel/centos               yum update-ed CentOS image                      0                    [OK]
ustclug/centos                 USTC centos                                    0                    [OK]
smartentry/centos             CentOS with smartentry                          0                    [OK]
repositoryjp/centos           Docker Image for CentOS.                        0                    [OK]

Quay.io private Dockerfiles

https://github.com/codemy/dockerfile contains Docker images containing mysql and elasticsearch hosted at the quay.io private repository.

BTW, a “quay” (pronounced “kee”) is a wharf where boats dock.

Sign in at https://quay.io/signin using your GitHub or Google credentials. pricing begin from $12/month for security scanning and geo-replication redundancy.

Run Dockerfile from GitHub

Run from my GitHub

In a Terminal, navigate to where you can add a repo.
Get it and navigate into the repo:
```
git clone https://github.com/wilsonmar/Dockerfiles && cd Dockerfiles
```
PROTIP: I recommend putting the Dockerfile for an app within that app’s repository rather than in a separate one.

List the contents of the repo:

ls -al

cd hello-world;docker run hello-world

Turn your Wi-Fi back on because the rest of this tutorial assumes it.

Other Dockerfiles from GitHub

Many have posted their collection of Dockerfiles publicly to GitHub:
- https://github.com/veggiemonk/awesome-docker#dockerfile has an annotated list of public repositories containing Dockerfile
- https://github.com/jessfraz/dockerfiles also live on dockerhub under jess. Because you cannot use notary with autobuilds on dockerhub I also build these continuously on a private registry at r.j3ss.co for public download. (You’re welcome.)
- https://github.com/yaronr/dockerfile
- https://github.com/vimagick/dockerfiles has over 500 stars.
- https://github.com/veggiemonk/awesome-docker has over 7.9K stars.
- https://github.com/kstaken/dockerfile-examples has a build step for salt, couchdb, rethinkdb
- https://github.com/jbergknoff/Dockerfile contains a Dockerfile for mysql, postgreSQL, redis, node, youtube-dl
- https://stefanscherer.github.io/is-there-a-windows-docker-image-for/ Nano servers containing Windows with .Net, ASP.NET, NodeJs, Python, Go,

Run Latest Nginx from Docker Hub

Run the latest version image pulled for nginx:
```
docker run -i -t nginx:latest /bin/bash
```
-i means interactive: Keep STDIN open even if not attached

-t means tty: Allocate a pseudo-TTY (command line)

Alternately:

Run an NGINX web server detached:
```
docker run -d -p 8080:80 nginx
```
-d specifies running in detached mode so the container continues to run in background until stopped, but does not respond to commands run on the command line.

-p means publish list: Publish a container’s port(s) to the host to set port mappings manually.

PROTIP: Even though we are using the MySQL default port, if we don’t tell docker explicitly we want to map it, it will block access through that port (because containers are isolated until you tell them you want access).

The “8000:80” means we’ll use http://localhost:8080.

The correct response is a hash, the container’s ID, such as:
```
254d5641eee4ef4882fe2d803068c9b6dd4477836406833a3cc71a0f7a31d36c
```

To see if that machine responds:

curl $(docker-machine ip default):8080


A common error message is like this:

curl: (7) Failed to connect to 192.168.99.100 port 8000: Connection refused


Fix the above by making sure you're specifying the correct port (8000 vs 80).


### List Docker processes

List the history of processes:

docker ps -a

Widen to see a response such as this, with random NAMES automatically assigned by Docker:

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS                    PORTS                         NAMES
0b7f9b9eb35a        hello-world         "/hello"                 4 hours ago         Exited (0) 4 hours ago                                  eager_lamarr
ago                                  compassionate_leakey
aa2ccdb153cc        nginx               "nginx -g 'daemon ..."   5 hours ago         Up 5 hours                0.0.0.0:80->80/tcp, 443/tcp   webserver

NOTE: The hello-world script contains an exit statement, so it automatically stopped on its own. However, other scripts, such as web services, do not exit on their own.

Get the history of space for an image:
```
docker history hello-world
```
To get the JSON associated with a 12-character container ID:
```
docker inspect 0b7f9b9eb35a



### Stop 
```
Stop running containers based on list:
```
docker stop $(docker ps -a -q)
```
The response is a list of container IDs like this:
```
254d5641eee4
dad20a229af5
62aa89bb8170
```
Remove the list of all containers listed:
```
docker rm $(docker ps -a -q)
```
See https://www.digitalocean.com/community/tutorials/how-to-remove-docker-images-containers-and-volumes

MySQL

DOC

To prevent attacks using default passwords, MySQL now requires its password to be changed when instantiated:

docker run --name db -d \
   -e MYSQL_ROOT_PASSWORD=123 \
   -p 3306:3306 mysql:latest

Connect to the image:
```
docker exec -it db /bin/bash
```
The prompt changes to include the Container ID:
```
root@39342b61defb:/# 
```

Run a process:

mysql -uroot -p123

The prompt changes to SQL after some information:

mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.7.20 MySQL Community Server (GPL)
 
Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
 
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
 
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
 
mysql>

Dependencies in Docker

When an application starts, it’s a problem if its dependencies are not available:

Load configuration settings from a JSON encoded config file
Access a working data directory
Establish a connection to an external mysql database

Traditionally, the approach is to ensure the database is started before starting the applications that depend on it by using Puppet, Chef, Ansible, or other configuration management tool.

“This is nothing more then a band-aid covering up the larger problem.” Kelsey Hightower says and recommends having app code handle the dependency problem. His sample in Go:

https://github.com/kelseyhightower/12-fractured-apps/blob/master/v3/main.go

TODO: Put startup-related code in a library for re-use.

load configuration files if it exists, but fall back to sane defaults.
Read environment variables to override configuration settings.
Manage working directories inside the application. If they are missing create them.
Retry the database connection, using some sort of backoff, and log errors along the way so alerts can be sent out.

This “defensive programming” code is the “optimistic” approach. It’s usually a transient problem. At some point the database will come online.

MySQL security

Docker does have different security requirements which can seem to be a hindrance.

Security can be integrated but it does require knowledge of the Linux container environment.

https://blog.docker.com/2013/08/containers-docker-how-secure-are-they/

Run custom reference

This blog shows this command to run image named “mynginx1”:
```
docker run \-\-name mynginx1 -P -d nginx \
fcd1fb01b14557c7c9d991238f2558ae2704d129cf9fb97bb4fadf673a58580d
```
“-P” (capital P) tells Docker to map the Ports exposed by the NGINX image – ports 80 and 443 – to ports on the Docker host randomly selected from the range between 49153 and 65535 each time the container is started or restarted. This is to avoid conflicts on standard ports 80 and 443 if we later create multiple NGINX containers on the same Docker host. The docker ps command under PORTS would show something like this:

0.0.0.0:49166->443/tcp, 0.0.0.0:49167->80/tcp

Ubuntu inside Mac

To run the latest Ubuntu box inside your Mac:
```
docker run -it --rm --publish 3000:3000 ubuntu bash
```
”–publish” forwards port 3000 on the host from port 3000 in the container.

“bash” is the command issued in the container when it becomes active. Alternately, “ruby /app/hello_world.rb” would invoke a ruby program.

Alternately, run version 14.04 of Ubuntu:
```
docker run --net=host \
-ti ubuntu:14.04 bash
```
After downloads, you should see a bash prompt such as:
```
root@ee355a835ff8:/# 
```
Get version information using a Linux command (which doesn’t work on MacOS):
```
cat /etc/lsb-release
```
The response:
```
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=16.04
DISTRIB_CODENAME=xenial
DISTRIB_DESCRIPTION="Ubuntu 16.04.1 LTS"
```
NOTE: You can’t run docker commands on this prompt because you’re inside.
Press Control+C or type exit:
```
exit
```
List Docker Containers

List Docker containers and their identifiers:

docker ps -a

PROTIP: In Linux the ps command is for processes. In a way, that’s what Docker containers are, a process.

-a shows inactive as well as the default active listing. (Kinda counter-intuitive)

Widen your screen to avoid wrapping:

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS                      PORTS                                           NAMES
2289fc019878        nginxdemos/hello    "nginx -g 'daemon off"   32 minutes ago      Up 32 minutes               0.0.0.0:32769->80/tcp, 0.0.0.0:32768->443/tcp   trusting_euler
75ae035ab68b        hello-world         "/hello"                 39 minutes ago      Exited (0) 39 minutes ago                                                   serene_sammet

PROTIP: Customize the layout by specifying a memory variable containing format template using tabs and line breaks.

\nID\t\{\{.ID}}\nIMAGE\t\{\{.Image}}\nCOMMAND\t\{\{.Command}}\nCREATED\t\{\{.RunningFor\}\}\nSTATUS\t\{\{.Status}}\n

docker ps -a --format $FORMAT

Manage Images Downloaded

To list Docker images downloaded:

docker images

REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
nginxdemos/hello    latest              0ec165d1eb3a        12 hours ago        54.24 MB
ubuntu              latest              f753707788c5        4 weeks ago         127.2 MB
hello-world         latest              c54a2cc56cbb        4 months ago        1.848 kB

List Docker machines:

docker-machine ls

Example response:

NAME      ACTIVE   DRIVER       STATE     URL                         SWARM   DOCKER    ERRORS
default   -        virtualbox   Running   tcp://192.168.99.100:2376           v1.12.3

See https://docs.docker.com/machine/get-started/

Connect your shell to the new machine (per https://docs.docker.com/machine/reference/env/):
```
eval "$(docker-machine env default)"
```
No response is displayed because the “eval” command above runs the output of the command:
```
docker-machine env default
```

Configre Docker client

# export DOCKER_TLS_VERIFY="1" specifies authentication of the Docker daemon 
# the client attempts to communicate with:
export DOCKER_TLS_VERIFY="1"
 
# export DOCKER_HOST informs the client of the socket location to use when 
# communicating with the Docker daemon:
export DOCKER_HOST="tcp://192.168.99.100:2376"
 
# export DOCKER_CERT_PATH specifies the location of key and certificates the 
# client uses for TLS-enabled communication:
export DOCKER_CERT_PATH="/Users/mac/.docker/machine/machines/default"
 
export DOCKER_MACHINE_NAME="default"
# Run this command to configure your shell: 
# eval $(docker-machine env)

PROTIP: On a Mac, the docker-machine VM is called “default”, existing in directory
/Users/<username>/.docker/machine/machines/default/

Verify the environment variables are set:
```
env | grep DOCKER
```
In the tls folder, edit the file CA-CSR.json that defines the algorithm (rsa), the size of bits (4096), and names of the OU hierarchy used to generate the cert:
```
cfssl gencert -initca ca-csr.json | cfssljson -bare ca -
```

File daemon-csr.json defines the CN (Common Name) and hosts as well used to generate the cert:

cfssl gencert -ca=ca.pem -ca-key=ca-key.pem \
   -config=ca-config.json -profile=daemon daemon-csr.json \
   | cfssljson -bare daemon -

Verify the daemon-key.pem and daemon.pem files were generated:
```
ls -l daemon*.pem
```
Use regex to specify all files to make readable:
```
chmod -v 0400 {ca,daemon}*.pem
```

Copy the file to where they are referenced:

sudo mkdir /etc/docker/tls
sudo cp {daemon*,ca}.pem /etc/docker/tls
rm -f daemon*.pem

After use, to unset environment variables:

eval $(docker-machine env -u)

which runs:

unset DOCKER_TLS_VERIFY
unset DOCKER_HOST
unset DOCKER_CERT_PATH
unset DOCKER_MACHINE_NAME
# Run this command to configure your shell: 
# eval $(docker-machine env -u)

Remove images

To remove an individual Docker image listed above (to free up disk space):
```
docker rmi hello-world
```
A common error response if you have not first

Error response from daemon: conflict: unable to remove repository reference “hello-world” (must force) - container 75ae035ab68b is using its referenced image c54a2cc56cbb

To stop all running docker containers:

docker stop $(docker ps -a -q)


The response is a list of CONTAINER ID's stopped, such as:

aa2ccdb153cc

To save disk space, remove containers identified in a list of container IDs obtained:
```
docker rm $(docker ps -a -q)
```
You may see this error message:
```
Error response from daemon: You cannot remove a running container aa2ccdb153cc54070e6e2ef24e004b40e3e78555b0bca77badd143c3d984bb1c. Stop the container before attempting removal or force remove
```
See https://docs.docker.com/docker-for-windows

Inside the container we will create a simple ‘Hello World’ script.none
```
powershell.exe Add-Content C:\helloworld.ps1 'Write-Host "Hello World"'
```
No Error Report

PROTIP: Whenever an attempt to provision a Dockerized host using Docker Machine fails, or Docker Machine crashes, some diagnostic information is sent automatically to a Docker account on Bugsnag.
Disable this reporting by creating an empty file called no-error-report under your installations .docker/machine directory:
```
touch ~/.docker/machine/no-error-report
```
Start using old boot2docker
Start again, you don’t need to specify “default”:
```
docker-machine start default
```

Connect:

docker-machine ssh

You should see a whale in ASCII art:

                        ##         .
               ## ## ##        ==
            ## ## ## ## ##    ===
        /"""""""""""""""""\___/ ===
   ~~~ {~~ ~~~~ ~~~ ~~~~ ~~~ ~ /  ===- ~~~
        \______ o           __/
          \    \         __/
           \____\_______/
 _                 _   ____     _            _
| |__   ___   ___ | |_|___ \ __| | ___   ___| | _____ _ __
| '_ \ / _ \ / _ \| __| __) / _` |/ _ \ / __| |/ / _ \ '__|
| |_) | (_) | (_) | |_ / __/ (_| | (_) | (__|   <  __/ |
|_.__/ \___/ \___/ \__|_____\__,_|\___/ \___|_|\_\___|_|
Boot2Docker version 1.12.3, build HEAD : 7fc7575 - Thu Oct 27 17:23:17 UTC 2016
Docker version 1.12.3, build 6b644ec

NOTE: Docker deprecated the Boot2Docker command line in favor of Docker Machine.

https://docs.docker.com/machine/migrate-to-machine/

Now do whatever you need to do here.

Stop
Hard stop the default machine:
```
docker-machine stop default
```
PROTIP: Those who use this a often create aliases to limit typing. For example, “dmon” for the above command.

docker-machine install

Docker Machine provisions Docker on virtual machines that reside on local or on a cloud provider.

NOTE: Docker Machine makes it easy to provision and manage multiple Docker hosts remotely from your personal computer.

Type the command by itself for a list of sub-commands:

docker-machine

The response shows the sub-commands and options available:

Usage: docker-machine [OPTIONS] COMMAND [arg...]
 
Create and manage machines running Docker.
 
Version: 0.8.2, build e18a919
 
Author:
  Docker Machine Contributors - <https://github.com/docker/machine>
 
Options:
  --debug, -D           Enable debug mode
  --storage-path, -s "/Users/mac/.docker/machine" Configures storage path [$MACHINE_STORAGE_PATH]
  --tls-ca-cert           CA to verify remotes against [$MACHINE_TLS_CA_CERT]
  --tls-ca-key            Private key to generate certificates [$MACHINE_TLS_CA_KEY]
  --tls-client-cert           Client cert to use for TLS [$MACHINE_TLS_CLIENT_CERT]
  --tls-client-key          Private key used in client TLS auth [$MACHINE_TLS_CLIENT_KEY]
  --github-api-token          Token to use for requests to the Github API [$MACHINE_GITHUB_API_TOKEN]
  --native-ssh            Use the native (Go-based) SSH implementation. [$MACHINE_NATIVE_SSH]
  --bugsnag-api-token           BugSnag API token for crash reporting [$MACHINE_BUGSNAG_API_TOKEN]
  --help, -h            show help
  --version, -v           print the version
   
Commands:
  active    Print which machine is active
  config    Print the connection config for machine
  create    Create a machine
  env     Display the commands to set up the environment for the Docker client
  inspect   Inspect information about a machine
  ip      Get the IP address of a machine
  kill      Kill a machine
  ls      List machines
  provision   Re-provision existing machines
  regenerate-certs  Regenerate TLS Certificates for a machine
  restart   Restart a machine
  rm      Remove a machine
  ssh     Log into or run a command on a machine with SSH.
  scp     Copy files between machines
  start     Start a machine
  status    Get the status of a machine
  stop      Stop a machine
  upgrade   Upgrade a machine to the latest version of Docker
  url     Get the URL of a machine
  version   Show the Docker Machine version or a machine docker version
  help      Shows a list of commands or help for one command
   
Run 'docker-machine COMMAND --help' for more information on a command.

Widen the Terminal window so lines don’t wrap.

Create a Docker machine on the Digital Ocean cloud:

docker-machine create -d digitialocean \
--digitalocean-access-token=secret

List Docker machine instances:

docker-machine ls

The response is a heading above lines, if any:

NAME   ACTIVE   DRIVER   STATE   URL   SWARM   DOCKER   ERRORS

List Docker machine Internet Protocol addresses:
```
docker-machine ip
```
The response:
```
192.168.99.100
```
Create Docker machine

Using your Mac’s Finder, look in your Applications folder for a Docker folder. In there is a Docker Quickstart Terminal.

You can also invoke it by typing on the Mac’s Search box.

It creates a window containing:

Creating CA: /Users/mac/.docker/machine/certs/ca.pem
Creating client certificate: /Users/mac/.docker/machine/certs/cert.pem
Running pre-create checks...
(default) Default Boot2Docker ISO is out-of-date, downloading the latest release...
(default) Latest release for github.com/boot2docker/boot2docker is v1.12.3
(default) Downloading /Users/mac/.docker/machine/cache/boot2docker.iso from https://github.com/boot2docker/boot2docker/releases/download/v1.12.3/boot2docker.iso...
Creating machine...
(default) Copying /Users/mac/.docker/machine/cache/boot2docker.iso to /Users/mac/.docker/machine/machines/default/boot2docker.iso...
(default) Creating VirtualBox VM...
(default) Creating SSH key...
(default) Starting the VM...
(default) Check network to re-create if needed...
(default) Found a new host-only adapter: "vboxnet1"
(default) Waiting for an IP...
 
                     ##         .
               ## ## ##        ==
            ## ## ## ## ##    ===
        /"""""""""""""""""\___/ ===
   ~~~ {~~ ~~~~ ~~~ ~~~~ ~~~ ~ /  ===- ~~~
        \______ o           __/
          \    \         __/
           \____\_______/
 
docker is configured to use the default machine with IP 192.168.99.100
For help getting started, check out the docs at https://docs.docker.com
 
bash: print: command not found

Create a Docker machine named node1 in the local Virtualbox, in debug mode:
```
docker-machine create -d virtualbox node1
```
Alternately, if you are running docker-machine on windows, you should use Hyper-V :
```
docker-machine create \-\-driver hyperv vm
```

Docker Compose

See https://docs.docker.com/compose/install/.

Compose file version 3 reference lists the correspondance between Compose file format and Docker Engine release.

Describe you stack in a docker-compose.yml. Example:

web:
   build .
   command: python app.py
ports:
 - "5000:5000"
volumes:
 - .:/code
links:
 - redis:redis
redis:
  image : redis

NOTE: Another example docker-compose.yml here

Type the command by itself for a list of sub-commands:

docker-compose

The response:

Define and run multi-container applications with Docker.
 
Usage:
  docker-compose [-f <arg>...] [options] [COMMAND] [ARGS...]
  docker-compose -h|--help
 
Options:
  -f, --file FILE             Specify an alternate compose file (default: docker-compose.yml)
  -p, --project-name NAME     Specify an alternate project name (default: directory name)
  --verbose                   Show more output
  -v, --version               Print version and exit
  -H, --host HOST             Daemon socket to connect to
 
  --tls                       Use TLS; implied by --tlsverify
  --tlscacert CA_PATH         Trust certs signed only by this CA
  --tlscert CLIENT_CERT_PATH  Path to TLS certificate file
  --tlskey TLS_KEY_PATH       Path to TLS key file
  --tlsverify                 Use TLS and verify the remote
  --skip-hostname-check       Don't check the daemon's hostname against the name specified
                           in the client certificate (for example if your docker host
                           is an IP address)
 
Commands:
  build              Build or rebuild services
  bundle             Generate a Docker bundle from the Compose file
  config             Validate and view the compose file
  create             Create services
  down               Stop and remove containers, networks, images, and volumes
  events             Receive real time events from containers
  exec               Execute a command in a running container
  help               Get help on a command
  kill               Kill containers
  logs               View output from containers
  pause              Pause services
  port               Print the public port for a port binding
  ps                 List containers
  pull               Pulls service images
  push               Push service images
  restart            Restart services
  rm                 Remove stopped containers
  run                Run a one-off command
  scale              Set number of containers for a service
  start              Start services
  stop               Stop services
  unpause            Unpause services
  up                 Create and start containers
  version            Show the Docker-Compose version information

https://docs.docker.com/compose/reference provides more detail.

Docker compose creates multiple containers with a single command:
```
docker-compose up --x-smart-recreate
```
The above command refers to Dockerfile and compose.yml files.

To start containers in the background and leaves them running:
```
docker-compose up -d
```
The above aggregates the output of each container (essentially running docker-compose logs -f).

Kubernetes

TOOL: Kompose is a convenience tool to go from local Docker development to managing your application with Kubernetes. Transformation of the Docker Compose format to Kubernetes resources manifest may not be exact, but it helps tremendously when first deploying an application on Kubernetes. Install on Windows machines:

choco install kubernetes-kompose

Monitoring

There are several alternatives to collects stats for monitoring dashboard:

opencensus.io vendor-agnostic distributes tracing to Zipkin, Yeager, Google Stackdriver Trace, etc.

AppDynamics Docker monitoring

Use https://github.com/google/cadvisor (Container Advisor) to analyzes resource usage and performance characteristics of running Docker containers. It keeps (in background) resource isolation parameters, historical resource usage, histograms of complete historical resource usage, and network statistics. Stats of NVIDIA GPU are also supported.

Might want to change the port number when you run the command:

sudo docker run \
  --volume=/:/rootfs:ro \
  --volume=/var/run:/var/run:ro \
  --volume=/sys:/sys:ro \
  --volume=/var/lib/docker/:/var/lib/docker:ro \
  --volume=/dev/disk/:/dev/disk:ro \
  --publish=8080:8080 \
  --detach=true \
  --name=cadvisor \
  google/cadvisor:latest

This describes setting up cAdvisor can write to InfluxDB time-series database for display by Grafana.

Get the IP address of the running Docker instance:

DOCKER_HOST=$(docker-machine ip $(docker-machine active))
curl -v http://$DOCKER_HOST  # visit in your browser.

Docker Swarm

Docker Swarm creates and manages clustered (pool of) Docker servers. It scales containers by dispersing containers across multiple hosts.

Be at a folder.
Download the wordpress-swarm.yml

Initializing Docker Swarm launches a container that is used as the Swarm Manager master which communicates with all nodes in a Swarm cluster.

docker swarm init

The response:*

Swarm initialized: current node (x3t9fal0if4a84mn7o5y1o6mf) is now a manager.
 
To add a worker to this swarm, run the following command:
 
 docker swarm join --token SWMTKN-1-0l1x7cjd605n2m1uo3w2il86kngdb2q0otzzhf2du2idshr0xw-0otui67aoq7r7tf7h3meqk6g1 192.168.65.3:2377
 
To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions.

Do it:

docker stack deploy -c wordpress-stack.yml  mywordpress

response:

Creating network mywordpress_default
Creating service mywordpress_wordpress
Creating service mywordpress_db

Get IP address of the host (“192.168.0.195”):

ip a

en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
 ether 8c:85:90:2b:ad:e9
 inet6 fe80::10e1:325e:a565:1a27/64 secured scopeid 0x8
 inet 192.168.0.195/24 brd 192.168.0.255 en0

Open the website:
```
http://192.168.0.195:80
```
If you get “Error establishing a database connection”

docker run swarm create

See https://docs.docker.com/swarm

docker run -d swarm join --addr=node_ip:2375 token://cluster_id

docker run -d -p swarm_port:2375 swarm manage token://cluster_id

See http://autopilotpattern.io

Debug within container

To reach the CLI console inside a Docker container, substitute example values in:
```
ssh -tt -i myKey user@remoteHost \
docker exec -it myContainer /bin/bash
```
myKey is the path to the private key.

user is the username for use by SSH.

remoteHost is the IP address of the Docker instance.

myContainer is the Docker Container ID listed by docker ps

More on DevOps

This is one of a series on DevOps:

Wilson Mar

Docker setup

VMs on MacOS vs. Docker

Docker for Mac

Recap

Alternatives to Docker

Linux installer boots

Setup Shell Script

GPG SecureApt

Install Docker on MacOS

Manual Docker for Mac

Clean up the installer

Open Docker client app

Previously

Install Docker on Windows 10+

Install in Amazon EC2 clouds

Install local Windows 10

Chocolatey

Manual install

Default folders

Alpine Linux

Install Docker in CentOS

Install Docker on Windows 10

After install, Menu, Verify

Full Docker Info

Container Registries

Setup Docker Hub

List and remove image

Setup Credential Store

Log into Docker Hub

Troubleshoot Docker daemon start

Modules installed

Set Maximum File Descriptors

Run from Docker Hub

Docker Help

Docker terminal inside the container

Docker pull

Dockviz

Base DockerHub Search

Windows Insider Images

Ubuntu search

Quay.io private Dockerfiles

Run Dockerfile from GitHub

Run from my GitHub

Other Dockerfiles from GitHub

Run Latest Nginx from Docker Hub

MySQL

Dependencies in Docker

MySQL security

Run custom reference

Ubuntu inside Mac

List Docker Containers

Manage Images Downloaded

Configre Docker client

Remove images

No Error Report

Start using old boot2docker

Stop

docker-machine install

Create Docker machine

Docker Compose

Kubernetes

Monitoring

Docker Swarm

Debug within container

More on DevOps

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