images and their layers
discover the image cache
- image layers
- union file system
-
history
andinspect
commands - copy on write
image layers
docker image history <image_name>
- all images start with "scratch"
- each layer gets a unique "sha" (sha256)
- don't need to download layers we already have in cache
- never storing multiple image layers
view image metadata
docker image inspect <image_name>
image tagging and pushing
- image id vs tag
- image don't have a "name"
- repository / tag / image id
- tag is not quite a 'version'
- tagging an image
docker image tag <source_image>[:tag] <target_name>[:tag]