mbentley/docker-in-docker repository overview

⁠mbentley/docker-in-docker

⁠Table of Contents

• Image Tags⁠
• Build images (optional)⁠
• Prerequisites⁠
• Single engine⁠
• Swarm mode cluster⁠

⁠Image Tags

For a complete list of published images, see the list of tags on Docker Hub⁠. For each major release, the specific Docker Enterprise bugfix versions are also available and can be found via Docker Hub.

• ce, latest (Dockerfile.ce⁠)
• ce-systemd (Dockerfile.ce-systemd⁠)
• ce-systemd-ssh (Dockerfile.ce-systemd-ssh⁠)

⁠Build images (optional)

Expand for more details

The images are published to Docker Hub so you do not need to build them unless you want to.

Note: the images build on each other. The ce tag is its own build and has no other dependencies other than ubuntu:20.04. The ce-systemd tag builds from ce. The ce-systemd-ssh tag builds from ce-systemd. So if you want to build ce-systemd-ssh, you should first build ce, then ce-systemd, and finally ce-systemd-ssh. This process is to re-use layers. I also recommend using docker build buildx as just docker build fails to re-use some layers that have no changed.

• Docker CE (stable)

  docker buildx build \
    --pull \
    --progress plain \
    --build-arg DOCKER_VER="$(wget -q -O - https://api.github.com/repos/moby/moby/releases/latest | jq -r .tag_name)" \
    --build-arg BUILDX_VER="$(wget -q -O - https://api.github.com/repos/docker/buildx/releases | jq -r 'map(select(.prerelease)) | first | .tag_name')" \
    -f Dockerfile.ce \
    -t mbentley/docker-in-docker:ce \
    .
  

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• Docker CE (with systemd)

  docker buildx build \
    -f Dockerfile.ce-systemd \
    -t mbentley/docker-in-docker:ce-systemd \
    .
  

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• Docker CE (with systemd + ssh)

  docker buildx build \
    -f Dockerfile.ce-systemd-ssh \
    -t mbentley/docker-in-docker:ce-systemd-ssh \
    .
  

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⁠Prerequisites

• Docker for Mac installed
• Must have the following ports available on your host:
  • 1000 - TCP connection to a single Docker engine (or whatever you specify)
  • 1001, 1002, 1003 - TCP connection to Docker engines for Swarm mode (or whatever you specify)

⁠Single engine

1. Start engine

   docker run -d \
     --init \
     --name docker \
     --hostname docker \
     --restart unless-stopped \
     --privileged \
     -p 127.0.0.1:1000:2375 \
     -v /lib/modules:/lib/modules:ro \
     -v docker-root:/root \
     -v docker-etc-docker:/etc/docker \
     -v docker-var-lib-docker:/var/lib/docker \
     -v docker-etc-cni:/etc/cni \
     -v docker-opt-cni:/opt/cni \
     -v docker-usr-libexec-kubernetes:/usr/libexec/kubernetes \
     -v docker-var-lib-kubelet:/var/lib/kubelet \
     -v docker-var-log:/var/log \
     --tmpfs /run \
     -e MOUNT_PROPAGATION="/" \
     mbentley/docker-in-docker \
     dockerd -s overlay2 -H unix:///var/run/docker.sock -H tcp://0.0.0.0:2375
   

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2. Communicate with that engine

   docker -H tcp://localhost:1000 info
   

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3. Check version

   docker -H tcp://localhost:1000 version
   

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4. Destroy the Engine

   docker kill docker
   docker rm docker
   docker volume rm docker
   

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⁠Swarm mode cluster

1. Create 3 engines

   for ENGINE_NUM in {1..3}
   do
     docker run -d \
       --init \
       --name docker${ENGINE_NUM} \
       --hostname docker${ENGINE_NUM} \
       --restart unless-stopped \
       --privileged \
       -p 127.0.0.1:100${ENGINE_NUM}:2375 \
       -v /lib/modules:/lib/modules:ro \
       -v docker${ENGINE_NUM}-root:/root \
       -v docker${ENGINE_NUM}-var-lib-docker:/var/lib/docker \
       -v docker${ENGINE_NUM}-etc-docker:/etc/docker \
       -v docker${ENGINE_NUM}-etc-cni:/etc/cni \
       -v docker${ENGINE_NUM}-opt-cni:/opt/cni \
       -v docker${ENGINE_NUM}-usr-libexec-kubernetes:/usr/libexec/kubernetes \
       -v docker${ENGINE_NUM}-var-lib-kubelet:/var/lib/kubelet \
       -v docker${ENGINE_NUM}-var-log:/var/log \
       --tmpfs /run \
       -e MOUNT_PROPAGATION="/" \
       mbentley/docker-in-docker \
       dockerd -s overlay2 -H unix:///var/run/docker.sock -H tcp://0.0.0.0:2375
   done
   

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2. Create a new Swarm

   docker -H tcp://localhost:1001 swarm init
   

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3. Get the worker join token and command

   TOKEN=$(docker -H tcp://localhost:1001 swarm join-token worker -q)
   JOIN_COMMAND="swarm join --token ${TOKEN} $(docker container inspect --format='{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' docker1):2377"
   

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4. Join engine 2

   docker -H tcp://localhost:1002 ${JOIN_COMMAND}
   

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5. Join engine 3

   docker -H tcp://localhost:1003 ${JOIN_COMMAND}
   

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6. Check status

   docker -H tcp://localhost:1001 node ls
   

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7. Destroy Swarm cluster

   docker kill docker1 docker2 docker3
   docker rm docker1 docker2 docker3
   docker volume rm docker1 docker2 docker3
   

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