Layers in docker image

Each Docker image references a list of read-only layers that represent filesystem differences.

Layers are stacked on top of each other to form a base for a container’s root filesystem.

Pull debian image to your local system. docker pull debian.

docker history debian shows you list of layers that debian image contains.

More Information you can find out with: docker inspect debian

Inspect the layers

More Information about an image you can find out with: docker inspect debian

There you will also see how the image is build and e.g. which command will executed at the container startup.

docker inspect debian | grep Cmd --after-context=10

To check which user the container runs as:

docker inspect debian | grep User --before-context=5

To find the SHA256 hash (ID) of the image, use:

docker inspect debian | grep Id

You can also use these to run the container:

docker run -it sha256:0af60a5c6dd017d7023f6b6c71f3ffbb9beb2948d842bcb1ba36d597fb96e75a