Docker is a software available since 2013 that among other features performs operating-system-level virtualization also known ascontainerization

Docker offer the following features:

• Package an application and its dependencies in a virtual container that can run on any Linux server (docker images)
• Pull or pushdocker images to acontainer repository/container registry (docker pull^[1],docker push). By default docker hub but you can specify any other registry.

You can read official Docker documentation about installing Docker on your system:https://docs.docker.com/install/.

On macOS you can follow official documentationhttps://docs.docker.com/docker-for-mac/install/ which requires to create and account to download installer. You can also try:brew cask install docker or try to followhttps://pilsniak.com/how-to-install-docker-on-mac-os-using-brew/ instructions:

brew install dockerdocker-compose docker-machine(to install docker and docker-compose)

brew cask install virtualbox

docker-machine create --driver virtualbox default

docker-machine ls

docker-machine env default

eval $(docker-machine env default)

docker run hello-world (will pull hello-world image and run it on docker)

On Ubuntu:snap install docker

Following binaries will be installed:docker-init,docker-proxy,docker anddockerd

Once installed the Dockerdaemon, called"dockerd" should be running. You can also rundocker run hello-world to verify docker correct installation.

• Ubuntu:/etc/docker/daemon.json

• https://docs.docker.com/engine/release-notes/
• https://github.com/docker/docker-ce/releases

Use:docker version^[2] to check your version.You can download Docker CE source code from GitHub^[3].

You can read official docker command line documentation inhttps://docs.docker.com/engine/reference/commandline/docker/. Before being able to run docker commands you will have to install Docker on your machine.

Some typical task using containers:

• Verify correct installation:docker run hello-world

You will see some message similar to this one:

Unable to find image 'hello-world:latest' locallylatest: Pulling from library/hello-worldca4f61b1923c: Pull completeDigest: sha256:97ce6fa4b6cdc0790cda65fe7290b74cfebd9fa0c9b8c38e979330d547d22ce1Status: Downloaded newer image for hello-world:latestHello from Docker!This message shows that your installation appears to be working correctly.To generate this message, Docker took the following steps: 1. The Docker client contacted the Docker daemon. 2. The Docker daemon pulled the "hello-world" image from the Docker Hub.    (amd64) 3. The Docker daemon created a new container from that image which runs the    executable that produces the output you are currently reading. 4. 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 bashShare images, automate workflows, and more with a free Docker ID: https://cloud.docker.com/For more examples and ideas, visit: https://docs.docker.com/engine/userguide/

• Create a new docker image base onalpine linux distribution and login into the new container:docker run -it alpine sh
• Create a new docker image:docker build
  • Create a new docker image by creating a new text file with instructions, usually calledDockerfile^[4]:docker build -f /path/to/a/Dockerfile .
• Create a container:docker create
• Generate a mediawiki:1.27 image:docker build --tag mediawiki:1.27 . (you can use -t or --tag)
• Execute or run a container based on mediawiki:1.27 image:docker run --name wikiFGA -p 0.0.0.0:9090:80 -d mediawiki:1.27

• Start an existing container:docker start CONTAINER_ID OR CONTAINER_NAME. See alsodocker run and differences^[5].
• Stop an running container:docker stop container_id

• Show only running containers:
  • docker container ls^[6] ordocker ps^[7]. (docker container ls) introduced in 2017 inDocker 1.13^[8] (There is no difference between both commands)^[9]

• Show containers (running or not):
  • docker ps -a:https://docs.docker.com/engine/reference/commandline/ps/
  • docker container ls -a. See alsodocker-compose ps

• Login/Connect into a running container:
  • docker exec[10] -it <my_container_name> bash
  • docker exec -it <my_container_name> sh

• Start stopped containers:docker start $(docker ps -a -q -f status=exited)
• Restart all containers:docker restart $(docker ps -aq) previouslydocker restart $(docker ps -q)-a all -q quiet^[11]

• Start configuration behavior and restart policy^[12]

See also:docker compose anddocker stack

• List created images:docker images^[13],docker image ls (both commands seems to perform the same action, note it is image instead of images)

Images are stored indocker info | grep "Docker Root Dir"^[14]

• docker image rm^[15]. See also:docker rm CONTAINER

• docker network ls
• docker network inspect
• Deprecated:docker --link^[16]

• Limit containerCPU usage to 0.5 cpus: docker run -it --cpus=".5" docker_image /bin/bash
• Limit memory requires your kernel to have functionality activated, you can check it executingdocker info. Seehttps://docs.docker.com/install/linux/linux-postinstall/ anddocker-compose resource limitation example:DevOps/Docker/docker compose/Version 3 resouces

You will be using mainly the following commandsdocker login,docker logout,docker pull anddocker push. Docker registry allow to configure notifications.^[17]. Docker has a public repository called Docker Hub and cloud providers offer repositories services such as AWS Elastic Container Registry (ECR).

• docker versionhttps://docs.docker.com/engine/reference/commandline/version/
• docker infohttps://docs.docker.com/engine/reference/commandline/info/
• docker stats
• docker system infohttps://docs.docker.com/v17.12/edge/engine/reference/commandline/system_info/
• docker system eventshttps://docs.docker.com/v17.12/edge/engine/reference/commandline/system_events/
• docker system df
• docker top [CONTAINER_NAME or CONTAINER_ID]https://docs.docker.com/engine/reference/commandline/top/
• docker inspect CONTAINER_ID|IMAGE_ID^[18]https://docs.docker.com/engine/reference/commandline/inspect/ also available for: container, image, volume, network, node, service, or task
• docker images,docker images -q
• docker image inspect^[19]
• docker image ls ordocker image ls --no-trunc

• docker run[20] IMAGE|IMAGE_ID:https://docs.docker.com/engine/reference/run/
• docker start CONTAINER_ID|CONTAINER_NAME:https://docs.docker.com/engine/reference/commandline/start/
• docker stop CONTAINER_ID|CONTAINER_NAME:https://docs.docker.com/engine/reference/commandline/stop/
• docker restart CONTAINER_ID|CONTAINER_NAME:https://docs.docker.com/engine/reference/commandline/restart/

• systemd-cgtop

• docker swarm^[21]
• docker nodes

• docker system prune -a remove unused and dangling images. Therefore any images being used in a container, whether they have been exited or currently running, will NOT be affected.^[22]

• docker volume:https://docs.docker.com/engine/reference/commandline/volume/
• docker volume ls:https://docs.docker.com/engine/reference/commandline/volume_ls/
• docker inspect -f 'Template:.Mounts' CONTAINER_NAME^[23]
• docker volumes prune

Docker support logging to format or different platforms, such as, json-file, syslog, journald, gelf, fluentd, awslogs, splunk, etwlogs, gcplogs and logentries.^[24]

• Configuration is done at docker container start time with commanddocker run -it --log-drive LOG_METHOD CONTAINER_ID
• Check method configured in a running container:
  • docker inspect -f 'Template:.HostConfig.LogConfig.Type' CONTAINER_ID
  • docker inspect -f 'Template:.HostConfig.LogConfig' CONTAINER_ID
• Viewlogs

docker logs CONTAINER_NAME_OR_ID (Docker Community Engine only support: local, json-file andjournald)

docker logs CONTAINER_NAME_OR_ID 2>&1 | grep "STRING_TO_SEARCH" (You will need to redirect outputs to be able to grep output)^[25]

Seehttps://docs.docker.com/config/containers/logging/ for more information

• docker tag^[26]

1. Read docker blog:https://blog.docker.com/
2. ReadDocker Engine release notes (2017) andDocker CE orDocker EE releases.
3. Understand the difference between an image and a container, Docker Images vs. Containers:https://stackoverflow.com/a/26960888
4. Understand the difference betweendocker start anddocker run:https://stackoverflow.com/questions/34782678/difference-between-running-and-starting-a-docker-container. See alsorunC
5. Read Stackoverflow questions related to docker:https://stackoverflow.com/questions/tagged/docker?tab=Votes

• Docker
• Docker Hub official Docker container imageregistry
• docker compose
• Jenkins X
• Cloud computing/Amazon Web Services/Elastic Container Service (ECS)
• AWS Elastic Container Registry (ECR)
• EKS,Kubernetes andPods
• DevOps/Container:runC
• Binary repository manager:DevOps/JFrog Artifactory
• containerd
• KVM,multipass

• DevOps