Docker

TL;DR

# Show locally available images.
docker images -a

# Search for images.
docker search boinc

# Pull images.
docker pull alpine:3.14
docker pull boinc/client:latest

# Login to registries.
docker login
docker login -u username -p password

# Create containers.
docker create -h alpine-test --name alpine-test alpine

# Start containers.
docker start alpine-test
docker start bdbe3f45

# Create and start containers.
docker run hello-world
docker run -ti --rm alpine cat /etc/apk/repositories
docker run -d --name boinc --network=host --pid=host -v "boinc:/var/lib/boinc" \
  -e BOINC_GUI_RPC_PASSWORD="123" -e BOINC_CMD_LINE_OPTIONS="--allow_remote_gui_rpc" \
  boinc/client

# Gracefully stop containers.
docker stop alpine-test
docker stop bdbe3f45

# Kill containers.
docker kill alpine-test

# Restart containers.
docker restart alpine-test
docker restart bdbe3f45

# Show containers' status.
docker ps
docker ps --all

# Execute commands inside *running* containers.
docker exec app_web_1 tail logs/development.log
docker exec -ti alpine-test sh

# Show containers' output.
docker log alpine-test

# List processes running inside containers.
docker top alpine-test

# Show information on containers.
docker inspect alpine-test

# Build a docker image.
docker build -t private/alpine:3.14 .

# Tag images.
docker tag alpine:3.14 private/alpine:3.14

# Push images.
docker push private/alpine:3.14

# Export images to tarballs.
docker save alpine:3.14 -o alpine.tar
docker save hello-world > hw.tar

# Load images from tarballs.
docker load -i hw.tar

# Delete containers.
docker rm alpine-test
docker rm -f 87b27

# Cleanup.
docker logout
docker rmi alpine
docker image prune -a
docker system prune -a

Daemon configuration

The docker daemon is configured using the /etc/docker/daemon.json file:

{
    "default-runtime": "runc",
    "dns": ['8.8.8.8', '1.1.1.1']
}

Containers configuration

Docker mounts specific system files in all containers to forward its settings:

6a95fabde222$ mount
…
/dev/disk/by-uuid/1bb…eb5 on /etc/resolv.conf type btrfs (rw,…)
/dev/disk/by-uuid/1bb…eb5 on /etc/hostname type btrfs (rw,…)
/dev/disk/by-uuid/1bb…eb5 on /etc/hosts type btrfs (rw,…)
…

Those files come from the volume the docker container is using for its root, and are modified on the container's startup with the information from the CLI, the daemon itself and, when missing, the host.

Gotchas

Containers created with no specified name will be assigned one automatically:

$ docker create hello-world
8eaaae8c0c720ac220abac763ad4b477d807be4522d58e334337b1b74a14d0bd

$ docker create --name alpine alpine
63b1a0a3e557094eba7f18424fd50d49b36cacbc21f1df60b918b375b857f809

$ docker ps -a
CONTAINER ID   IMAGE         COMMAND    CREATED          STATUS    PORTS   NAMES
63b1a0a3e557   alpine        "/bin/sh"  24 seconds ago   Created           alpine
8eaaae8c0c72   hello-world   "/hello"   21 seconds ago   Created           sleepy_brown

When referring to a container or image using their ID, you just need to use as many characters you need to uniquely specify a single one of them:

$ docker ps -a
CONTAINER ID   IMAGE         COMMAND    CREATED          STATUS    PORTS   NAMES
63b1a0a3e557   alpine        "/bin/sh"  34 seconds ago   Created           alpine
8eaaae8c0c72   hello-world   "/hello"   31 seconds ago   Created           sleepy_brown

$ docker start 8
8

$ docker ps -a
CONTAINER ID   IMAGE         COMMAND    CREATED          STATUS                      PORTS   NAMES
63b1a0a3e557   alpine        "/bin/sh"  48 seconds ago   Created                             alpine
8eaaae8c0c72   hello-world   "/hello"   45 seconds ago   Exited (0) 10 seconds ago           sleepy_brown

4.0 KiB Raw Blame History

Docker

TL;DR

Daemon configuration

Containers configuration

Gotchas

Sources

4.0 KiB

Raw Blame History