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[2] Advance Docker

Before you haven't learned the Docker, please check the basic instruction first.

How to push an image to Docker Hub​

Sometimes we will make a customized docker image whatever it is built from dockerfile or from a new commit. We can push to our dockerhub for sharing and reuse on different devices.

  1. Let's go to Dockerhub and login.

  2. If you do not have a repository for this project, let's create a new one. Click "Create Repository".

    Basically you will see the similar page as below.

    Then we can see a new repository on the dockerhub and it will show the hint to tell you how can you push an image to this repository.

  3. Log into the DockerHub first on our terminal. 

    docker login -u (your account)

  4. Change the tag of your image. We can use docker images to check all images first.

    $ docker images
    REPOSITORY                                           TAG                                IMAGE ID            CREATED             SIZE
    ubuntu                                               20.04                              3bc6e9f30f51        10 days ago         72.8MB

    So if I wanna push the ubuntu image to my example DockerHub repository, then I need to change the tag name.

    $ docker tag ubuntu:20.04 chiehpower/example:20.04

    $ docker images
    REPOSITORY                                           TAG                                IMAGE ID            CREATED             SIZE
    chiehpower/example                                   20.04                              3bc6e9f30f51        10 days ago         72.8MB
    ubuntu                                               20.04                              3bc6e9f30f51        10 days ago         72.8MB

  5. And then we can push this image to our dockerhub.

    $ docker push chiehpower/example:20.04

    The push refers to repository [docker.io/chiehpower/example]
    c3f11d77a5de: Pushed
    20.04: digest: sha256:a06ae92523384c2cd182dcfe7f8b2bf09075062e937d56537d0db0375ad221 size: 529

  6. Check the image on our repository of Dockerhub.

    Done~

Other docker commands​

docker save​

Export an image to a file.

docker save (REPOSITORY):(TAG) > (File name).tar.gz

docker load​

Load an image from a file.

docker load < (File name).tar.gz

docker volume​

docker volume create (container name)

Reference

Clean docker image​

We can use this command to clean the images that we did not use it anymore such as <images>:<None>. 

docker image prune -f

However, it will not delete unless images.

Dockerfile​

Please directly check my slide.

To fix the source problem:

Platform: amd64

sed -i -e 's/archive.ubuntu.com/free.nchc.org.tw/' /etc/apt/sources.list

Platform: arm

sudo sed -i'' 's/ports\.ubuntu\.com\/ubuntu-ports/free\.nchc\.org\.tw\/ubuntu-ports/' /etc/apt/sources.list

docker-compose​

Resource limit​

deploy:
  resources:
    limits:
      # cpus: '0.10'
      memory: 200000M
    reservations:
      memory: 180000M
      devices:
      - driver: nvidia
        device_ids: ["GPU-b051e1e7-7531-b420-8827-892b063833d2"]
        capabilities: [gpu]

Volume​

You can set the host path for volume mounting: container path (:container) or additional access mode (host:container:ro) ro is read-only mode.

For example:

volumes:
 - /var/lib/mysql:/var/lib/mysql
 - /configs/mysql:/etc/configs/:ro

Achieve to docker-in-docker​

docker run -ti -v /var/run/docker.sock:/var/run/docker.sock docker

"Real" docker-in-docker

docker run --privileged -d docker:dind

Storage​

info

I changed the storing image and container location of Docker.

/etc/docker/daemon.json 
{
    "runtimes": {
        "nvidia": {
            "path": "nvidia-container-runtime",
            "runtimeArgs": []
         }
    },
    "graph": "/home/user/Docker",
    "storage-driver": "overlay2",
    "insecure-registries":["0.0.0.0:5555"]
}

We can use this command to check your all docker size.

$ sudo du -h ~/Docker --max-depth 1                                                                       
4.0K    /home/user/Docker/runtimes
72K /home/user/Docker/buildkit
4.0K    /home/user/Docker/trust
20K /home/user/Docker/builder
20K /home/user/Docker/plugins
70G /home/user/Docker/containers
39G /home/user/Docker/volumes
53M /home/user/Docker/image
32G /home/user/Docker/overlay2
4.0K    /home/user/Docker/tmp
268K    /home/user/Docker/network
4.0K    /home/user/Docker/swarm
140G    /home/user/Docker

If you create a new container, it will accumulate the space in this /home/user/Docker/overlay2 folder.

Also, we can use this command to release useless docker image and container.

docker system prune -a

X11​

If you wanna pop up a windows inside a Docker container, you need to give a env and mount the .X11-unit.

For example:

docker run -it -d --gpus all \ 
            --privileged \
            --name chieh \
            --net=host \
            --user=root:root \
            --env=DISPLAY \
            -v /tmp/.X11-unix:/tmp/.X11-unix:rw \ 
            chieh-docker-image:latest

Also, type the command on host:

sudo xhost +