From a4676503d9531b50b26643df5ea3975bdec6b4df Mon Sep 17 00:00:00 2001 From: Ankush Agarwal Date: Tue, 21 Apr 2015 12:47:09 -0700 Subject: [PATCH] Add Image Digest doc in userguide/dockerimages Fixes #12551 Signed-off-by: Ankush Agarwal --- docs/sources/userguide/dockerimages.md | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/docs/sources/userguide/dockerimages.md b/docs/sources/userguide/dockerimages.md index f97231506e..fc5dbe74a0 100644 --- a/docs/sources/userguide/dockerimages.md +++ b/docs/sources/userguide/dockerimages.md @@ -505,6 +505,25 @@ Let's see our new tag using the `docker images` command. ouruser/sinatra devel 5db5f8471261 11 hours ago 446.7 MB ouruser/sinatra v2 5db5f8471261 11 hours ago 446.7 MB +## Image Digests + +Images that use the v2 or later format have a content-addressable identifier +called a `digest`. As long as the input used to generate the image is +unchanged, the digest value is predictable. To list image digest values, use +the `--digests` flag: + + $ docker images --digests | head + REPOSITORY TAG DIGEST IMAGE ID CREATED VIRTUAL SIZE + ouruser/sinatra latest sha256:cbbf2f9a99b47fc460d422812b6a5adff7dfee951d8fa2e4a98caa0382cfbdbf 5db5f8471261 11 hours ago 446.7 MB + +When pushing or pulling to a 2.0 registry, the `push` or `pull` command +output includes the image digest. You can `pull` using a digest value. + + $ docker pull ouruser/sinatra@cbbf2f9a99b47fc460d422812b6a5adff7dfee951d8fa2e4a98caa0382cfbdbf + +You can also reference by digest in `create`, `run`, and `rmi` commands, as well as the +`FROM` image reference in a Dockerfile. + ## Push an image to Docker Hub Once you've built or created a new image you can push it to [Docker