Where can I find the sha256 code of a docker image?
Latest answer
Edit suggested by OhJeez in the comments.
docker inspect --format='{{index .RepoDigests 0}}' $IMAGEOriginal answer
I believe you can also get this using
docker inspect --format='{{.RepoDigests}}' $IMAGEWorks only in Docker 1.9 and if the image was originally pulled by the digest. Details are on the docker issue tracker.
You can get it by docker images --digests
REPOSITORY TAG DIGEST IMAGE ID CREATED SIZEdocker/ucp-agent 2.1.0 sha256:a428de44a9059f31a59237a5881c2d2cffa93757d99026156e4ea544577ab7f3 583407a61900 3 weeks ago 22.3 MB
Simplest and most concise way is:
docker images --no-trunc --quiet $IMAGEThis returns only the sha256:... string and nothing else.
e.g.:
$ docker images --no-trunc --quiet debian:stretch-slimsha256:220611111e8c9bbe242e9dc1367c0fa89eef83f26203ee3f7c3764046e02b248Edit:
NOTE: this only works for images that are local. You can docker pull $IMAGE first, if required.