Docker

Quick notes

Commands

  • docker images
  • docker run -it ubuntu <shell>
    • -v <host_dir>/<container_dir>
    • -p
    • --rm, automatically aremove the container when it exists
  • docker exec -it <container_name> bash
  • docker history <image>
  • 自下而上构建镜像层的缓存，<...>: Already existes
  • docker ps
    • -a for all

UID

id, return user identity

  • When we use file in host machine as volumem it’s important to set the SAME UID.
  • Another way is mount your /etc/group and /etc/passwd to your container.
    • This method is post in the cooments under the post referenced above.

Alpine commands

Install packages only for building

apk add --no-cache --virtual .build-dependencies <packages>
apk del .build-dependencies

Add new user

RUN addgroup -S app && adduser -S -g app app

or

adduser -D -u 1000 [username]

Clear dangling data

Dangling data includes:

  • containers stopped
  • volumes without containers
  • images with no containers
  • -a for unused data
# Command to run all prunes:
docker system prune

# Remove unused images
docker image prune

# Remove stopped containers.
docker container prune

# Remove unused volumes
docker volume prune

# Remove unused networks
docker network prune

docker rmi <image_name>, remove image

Volume