There are a number of logical constructs in docker. Images which are built from a Dockerfile contain an OS and all the libraries and configs needed to run some program. Containers are created from an image and represent an actual running (or stopped) version of an application. Volumes are used by containers for persistent storage. There are also docker-compose.yml files which are used to tie together a bunch of these containers and volumes into a single service. These are very useful if you have a bunch of micro-services.

kubernetes

For managing groups of computers "nodes" running docker containers.

huge power usage

https://www.beatworm.co.uk/blog/thinkpad/docker-ate-my-battery

As a result I tend to keep docker disabled on void linux. To re-enable it:

sudo ln -s /etc/sv/containerd /var/service/
sudo ln -s /etc/sv/docker /var/service/

images

building

This builds and locally installs your image. docker build .

-t 'name:tag' - Name and optionally tag the image.

list locally installed images

docker images

remove installed image

docker rmi name

remove all images

docker rmi -f $(docker images -aq)

run (create and start)

This creates a "container" from your image and starts it up. If you don't name the container it gets a random automatic one. docker run name:tag

-d - Detach and run container in the background.

-p 8080:80 - Allow access on a certain port. This maps 8080 on the local machine to 80 in the container.

--name - Name the container rather than using docker's auto generated names.

containers

By default docker containers are restriced with limited system resources and their own network which cannot by default interact with the host system. Ensure you permit anything needed.

create (container from image)

Alternatively to run you can create a container from an image without also starting it. docker create

remove installed container

docker rm name

remove all containers

docker rm -vf $(docker ps -aq)

start or stop containers

docker start name
docker stop name

list running images/containers

docker ps

-a - All. Include non-running containers in the list.

logs

Print out the logs from a container without attaching to it. docker logs name

-f - Follow the logs. Continue printing output.

compose (stacks)

Compose reads a docker-compose.yml file and builds any missing images, then creates and starts any containers needed with the config options (such as opened ports). This is a simple and rather limited container orchestration tool, like kubernetes. It's useful for smaller deployments where kubernetes would add unnecessary complexity.

docker compose up -d

volumes

Used for persistent storage.

override hosts

--add-host hostname:ip

launch options for the container

Believe it or you can add launch options for the container at the end of a docker run command:

docker run -d -p 8000:8000 -p 9443:9443 --name portainer --restart=always --add-host api.portainer.io:127.0.0.1  -v /var/run/docker.sock:/var/run/docker.sock -v portainer_data:/data portainerci/portainer-ee:2.20 --license-expire-absolute --log-level=DEBUG