Documentation for Docker

26.09.21

CLI v Desktop

I think I’ll be using the Docker CLI interface. The docker documentation nudges me toward the Desktop products, but I’m not sure I need that. I have used the CLI interface in the past, and that seems to be the most intuitive for development, for me.

Heres a comparison from geeks for geeks # Docker CLI vs Docker Desktop

Why do something in a difficult way when it can be done easier? Is a question I struggle with when deciding these things. If the desktop application is more powerful, why struggle with CLI? Because I am protestant?

Installed Docker engine using APT: https://docs.docker.com/engine/install/ubuntu/

  • no problems

CLI getting started

####### Important commands: After installation, verify that Docker is running:

 sudo systemctl status docker

If Docker is not running, start it manually:

 sudo systemctl start docker

Detaching from a container once it is running:

Once attached to a container, users detach from it and leave it running using the using CTRL-p CTRL-q key sequence. This detach key sequence is customizable using the detachKeys property. […]

Viewing containers:

karri@karri-ThinkPad-P1-Gen-3:~$ sudo docker ps -a
CONTAINER ID   IMAGE         COMMAND    CREATED         STATUS                     PORTS     NAMES
07c17d6c157b   ubuntu        "bash"     5 minutes ago   Up 5 minutes                         thirsty_shaw
d7c356190a1f   hello-world   "/hello"   5 minutes ago   Exited (0) 5 minutes ago             wonderful_herschel

Stopping a container after it has started running and user has detached from it:

karri@karri-ThinkPad-P1-Gen-3:~$ sudo docker container stop thirsty_shaw
thirsty_shaw
karri@karri-ThinkPad-P1-Gen-3:~$ sudo docker ps -a
CONTAINER ID   IMAGE         COMMAND    CREATED         STATUS                       PORTS     NAMES
07c17d6c157b   ubuntu        "bash"     7 minutes ago   Exited (137) 4 seconds ago             thirsty_shaw
d7c356190a1f   hello-world   "/hello"   7 minutes ago   Exited (0) 7 minutes ago               wonderful_herschel

26.09.30

A container is a running image

Running multiple parts of a application as containers can be done efficiently with docker compose, using a compose.yaml file.

  • This way the different parts of the application can be held separate as their own modules, and calls to the application api can be managed by a proxy

After starting an application instance that has multiple containers, you can stop and remove them by:

karri@karri-ThinkPad-P1-Gen-3:~/getting-started-todo-app$ sudo docker rm --force todo
karri@karri-ThinkPad-P1-Gen-3:~/getting-started-todo-app$ l
backend/  client/  compose.yaml  Dockerfile  LICENSE  README.md
karri@karri-ThinkPad-P1-Gen-3:~/getting-started-todo-app$ sudo docker compose down --volumes
[+] down 6/6
 ✔ Container getting-started-todo-app-client-1     Removed                                                                                      0.6s
 ✔ Container getting-started-todo-app-proxy-1      Removed                                                                                      4.8s
 ✔ Container getting-started-todo-app-mysql-1      Removed                                                                                      0.6s
 ✔ Container getting-started-todo-app-phpmyadmin-1 Removed                                                                                      1.2s
 ✔ Volume getting-started-todo-app_todo-mysql-data Removed                                                                                      0.0s
 ✔ Network getting-started-todo-app_default        Removed

the compose down command will remove the containers, but keep the images and volumes. the –volumes flag deletes objects in persistent storage, like contents of DBs

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