docker pull

docker images, docker image ls

docker image ls warehouse name/image name

docker image rm

docker system df

docker image ls -f dangling=true

The old and new images have the same name. After using the docker pull or docker build command, the old image name is cancelled, and the warehouse name and label are both <none>.

Images that other upper-layer images depend on are labeled <none>. Use docker image ls -a to view images including middle-layer images. The middle layer image should not be deleted. When the upper layer image is deleted, the middle layer image will be deleted.

An image has multiple tags. Untagged is the tag used to cancel the image. Deleted is triggered when all tags in the image are Untagged.

The deletion of the image is from the upper layer to the base layer. When the current layer is dependent on other images, the deletion behavior will not be triggered; if there is a container running based on the image, the deletion behavior will not be triggered.

effect

Image build context (Context)

Specify the base image, the required first line of instructions

Maintainer information

Start a container, execute the command, and commit the storage layer file changes

Copy files (Note: The <target path> of COPY can be the absolute path of the container or the path relative to the working directory (the directory specified by WORKDIR))

Copy files and automatically unzip them

Define anonymous volumes

Declared port: (1) Helps explain the port used; (2) When the container is running using random port mapping, it is automatically mapped to the port specified by EXPOSE

Specify the working directory. The current directory of each layer will be the directory specified by WORKDIR.

Specify the command to be executed when the container starts

After specifying ENTRYPOINT, the content of CMD will be passed to ENTRYPOINT as a parameter.

Set environment variables

Environment variables are set, but the environment variables will not exist when the container is running

After specifying a user using USER, the RUN, CMD, and ENTRYPOINT commands will be executed using this user.

health examination

docker run

docker container start (start the container in the terminated state)

docker container stop

docker attach

docker exec

docker container rm (remove terminated container)

docker container rm -f (delete running container)

docker container prune (clean up all terminated containers)