Notes to Self

Alex Sokolsky's Notes on Computers and Programming

Docker Cheat Sheet



sudo apt update
sudo apt install apt-transport-https ca-certificates curl gnupg lsb-release -y
curl -fsSL | \
   sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg

Identify the Ubuntu codename on which my Mint is based:

root@latitude7490:/tmp# cat /etc/os-release |grep -i ubuntu
ID_LIKE="ubuntu debian"

In the following replace jammy with the relevant Ubuntu codename:

echo "deb [arch=amd64 signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] jammy stable" \
  | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null


sudo apt update
sudo apt-get install docker-ce docker-ce-cli


Verify the install with docker run:

> docker --version
Docker version 20.10.21, build baeda1f

> sudo docker run hello-world

Hello 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.
 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 bash

Share images, automate workflows, and more with a free Docker ID:

For more examples and ideas, visit:


The location for client configuration files is determined by DOCKER_CONFIG environment variable, seems to default to $HOME/.docker. More on docker environment variables.

Configuration files include:



Show (standard) networks:

root@suprox:~# docker network ls
6eef1bc6ffc5   bridge    bridge    local
35dbeb62ddb4   host      host      local
e023fada21bd   none      null      local
root@suprox:~# docker network inspect host
        "Name": "host",
        "Id": "35dbeb62ddb42ebca3f5e2eae576921229b1279b496c387b78ef2c4ced5c70d8",
        "Created": "2023-02-10T18:31:29.131467146-08:00",
        "Scope": "local",
        "Driver": "host",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": []
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        "ConfigOnly": false,
        "Containers": {},
        "Options": {},
        "Labels": {}

Inspect the bridge network to see which containers are connected to it:

root@suprox:~# docker network inspect bridge
        "Name": "bridge",
        "Id": "6eef1bc6ffc530537c94652428cc80a295102845a84eb9ab18e40e8b6d666ee2",
        "Created": "2023-02-10T18:31:29.14533915-08:00",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": [
                    "Subnet": ""
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        "ConfigOnly": false,
        "Containers": {
            "3dca544da1ce64d8c5a970b38a8ab340e958b86ee36bc2ee4aa0b44035ec21d0": {
                "Name": "mjpg-streamer",
                "EndpointID": "b1b45b71ba4df575fcbd35650902860691e6f9dbcc82d608e8f4b992322cbe42",
                "MacAddress": "02:42:ac:11:00:03",
                "IPv4Address": "",
                "IPv6Address": ""
            "bf42b1b5a4f78204a307323c514e22c402950f695e1d51e8c5df0c407dc66f98": {
                "Name": "portainer",
                "EndpointID": "617ed40e256b0a96dfbb5a74853dad400bc048797c11070735d4bb2b76787987",
                "MacAddress": "02:42:ac:11:00:02",
                "IPv4Address": "",
                "IPv6Address": ""
        "Options": {
            "": "true",
            "": "true",
            "": "true",
            "": "",
            "": "docker0",
            "": "1500"
        "Labels": {}

List images

docker image ls

better yet:

docker images --digests

More on docker image.

List containers

docker container. List running:

docker container ls

Can also use docker ps.

List all containers, not only running, do not truncate output:

docker container ls -a --no-trunc

List IDs only:

docker container ls -q

Kill all containers

Force delete all containers:

docker container rm -f $(docker container ls -aq)

Inspect the container

Inspecting container produces JSON:

sudo docker inspect _container_id_

Extract container environment and sort it.

sudo docker inspect _container_id_ | jq ".[0].Config.Env|sort[]"

Display the account (username/group) used by the container:

sudo docker inspect _container_id_ | jq ".[].Config.User"

Get a Shell in a Container

docker container exec -itu root _container_id_or_name_ /bin/bash
Option Description    
-i, --interactive interactive, keep STDIN open even if not attached    
-t, --tty allocate a pseudo-TTY    
-u, --user username username or UID, format: <name uid>[:<group gid>]

Container logs

Default location: /var/lib/docker/containers/<container_id>/<container_id>-json.log. logging drivers can change that.

docker logs docs


docker logs <container_id>

To tail (or to follow) the log:

docker logs <container_id> -f


root@suprox:~# docker stats mjpg-streamer portainer
CONTAINER ID   NAME            CPU %     MEM USAGE / LIMIT     MEM %     NET I/O           BLOCK I/O     PIDS
3dca544da1ce   mjpg-streamer   0.11%     1.75MiB / 31.26GiB    0.01%     7.12MB / 1.48GB   0B / 0B       4
bf42b1b5a4f7   portainer       0.00%     12.59MiB / 31.26GiB   0.04%     3.29MB / 8.37MB   0B / 25.4MB   7

Build it

Create Dockerfile. Then use command docker build to build and tag the image:

docker build -t my_stuff .

Run it

Run an image in a container using docker run. If you need to provide input for stdin, use -i option:

cat secrets.txt | docker run --pull=always -i my_stuff
Command Description
docker run <image> Create and run a new container
docker run -p 8080:80 <image> Publish container port 80 to host port 8080
docker run -d <image> Run a container in the background
docker run -v <host>:<container> <image> Mount a host directory to a container
docker ps List currently running containers
docker ps --all List all containers (running or stopped)
docker logs <container_name> Fetch the logs of a container
docker logs -f <container_name> Fetch and follow the logs of a container
docker stop <container_name> Stop a running container
docker start <container_name> Start a stopped container
docker rm <container_name> Remove a container

Executing commands in a container

Command|Description ——-|———– docker exec <container_name> <command>|Execute a command in a running container docker exec -it <container_name> bash|Open a shell in a running container

Image commands

Command|Description ——-|———– docker build -t <image> .|Build a new image from the Dockerfile in the current directory and tag it docker images|List local images docker rmi <image>|Remove an image

Container registry commands

Command Description
docker login Login to Docker Hub
docker login <server> Login to another container registry
docker logout Logout of Docker Hub
docker logout <server> Logout of another container registry
docker push <image> Upload an image to a registry
docker pull <image> Download an image from a registry
docker search <image> Search Docker Hub for images

System commands

Command Description
docker system df Show Docker disk usage
docker system prune Remove unused data
docker system prune -a Remove all unused dat