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Version: 8.9.x

Docker Vademecum

Why Docker​

The purpose of Docker is to make it easier to create, deploy and run applications using containers. Containers allow the developer to package an application with all the necessary parts (libraries and other related resources) and deliver it as a single package.

In this way, thanks to Container, the developer is certain that the application will run on any Linux machine regardless of any customization of the settings of that same machine, settings for which that machine may differ from the one that was used for write the application or to test the code.

Installation​

Linux​

We offer 3 different alternatives to install docker:

  1. Tutorial for those who have never used Docker
  2. Generic script provided by docker: curl -sSL https://get.docker.com/ | sh
  3. For those who want to follow the specific instructions on their operating system

MacOS​

Follow the following steps:

  1. Download and Install Docker Community Edition
  2. Once installed click on the icon and start the app: docker run hello-world

Basic Commands - Life Cycle​

  • docker create creates a container but does not start it.
  • docker rename allows you to rename the container.
  • docker run creates and starts a container in one operation.
  • docker rm deletes a container.
  • docker update updates the resource limits of a container.

Start and Stop​

  • docker start starts a container so that it is running.
  • docker stop stops a running container.
  • docker restart stops and starts a container.
  • docker pause pauses a working container," freezing it "instead.
  • docker unpause will reactivate a running container.
  • docker wait blocks until the container stops.
  • docker kill sends a SIGKILL to a running container.
  • docker attach will connect to a working container.

Information​

  • docker ps shows the working containers.
  • docker logs gets the logs from the container.
  • docker inspect gets all the information about a container (including the IP address).
  • docker events gets events from the container.
  • docker port shows the public port of the container.
  • docker top shows the processes running in the container.
  • docker stats shows statistics on the use of container resources.
  • docker diff shows the modified files in the container's FS.
  • docker ps -a shows the working and stopped containers.
  • docker stats --all shows the list of running containers.

Import / Export​

  • docker cp copies files or folders between a container and the local filesystem.
  • docker export transforms the container filesystem into the tarball archive stream in STDOUT.

Docker images​

The images are container templates. At this link more information.

  • docker images shows all images.
  • docker import creates an image from a tarball.
  • docker build creates an image from Dockerfile.
  • docker commit creates an image from a container, temporarily interrupting it if it is running.
  • docker rmi removes an image.
  • docker load loads an image from a tar archive like STDIN, including images and tags (starting at 0.7).
  • docker save saves an image in a tar archive stream on STDOUT with all levels, tags and parent versions (starting at 0.7).
  • docker history shows the history of the image.
  • docker tag tags an image with a name (local or registry).

To this Link more useful tips