List available tags of image hosted by registry via docker command

[winny-]

• [ ] This is a bug report
• [x] This is a feature request
• [x] I searched existing issues before opening this one

Expected behavior

I found an interesting image (example: eldesh/smlnj) via docker search ... I wanted to try out, but when I tried pulling it, it said the tag latest wasn't found. I was hoping to list available tags from within docker(1), but it turned out only possible via an external script (using the registry API), or visiting the registry website.

An alternative I also found was run docker pull -a ... (and then list the images afterwards) but that tends to use more storage/bandwidth than one might hope.

Actual behavior

I had to volunteer ~2.5 GiB of disk space to run docker pull -a eldesh/smlnj though I could have used the api or visited the website to obtain a list of tags.

Steps to reproduce the behavior

1. Find an interesting image: docker search smlnj (in this case eldesh/smlnj)
2. Try to pull it: docker pull eldesh/smlnj, but get the following output:

Using default tag: latest
Error response from daemon: manifest for eldesh/smlnj:latest not found

3. Try to find way to get list of tags via docker(1), but best option is docker pull -a eldesh/smlnj at the cost of extra downloads and disk space.

Output of docker version:

Client:
 Version:      18.03.1-ce
 API version:  1.37
 Go version:   go1.10.3
 Git commit:   9ee9f40
 Built:        Sat Jul 28 16:09:24 2018
 OS/Arch:      linux/amd64
 Experimental: false
 Orchestrator: swarm
Server:
 Engine:
  Version:      18.03.1-ce
  API version:  1.37 (minimum version 1.12)
  Go version:   go1.10.3
  Git commit:   9ee9f40
  Built:        Sat Jul 28 16:08:49 2018
  OS/Arch:      linux/amd64
  Experimental: false

Output of docker info:

Containers: 38
 Running: 0
 Paused: 0
 Stopped: 38
Images: 166
Server Version: 18.03.1-ce
Storage Driver: overlay2
 Backing Filesystem: extfs
 Supports d_type: true
 Native Overlay Diff: true
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins:
 Volume: local
 Network: bridge host macvlan null overlay
 Log: awslogs fluentd gcplogs gelf journald json-file logentries splunk syslog
Swarm: inactive
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version: 773c489 (expected: 773c489c9c1b21a6d78b5c538cd395416ec50f88)
runc version: 4fc53a81fb7c994640722ac585fa9ca548971871
init version: v0.16.1 (expected: 949e6facb77383876aeff8a6944dde66b3089574)
Security Options:
 seccomp
  Profile: default
Kernel Version: 4.14.65-gentoo
Operating System: Gentoo/Linux
OSType: linux
Architecture: x86_64
CPUs: 8
Total Memory: 15.54GiB
Name: snowcrash
ID: NUVV:J4I2:N2SL:ZEVR:7PMN:QDAX:AUNX:KAXM:5GQB:QZGB:RNWJ:EGFC
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): false
Registry: https://index.docker.io/v1/
Labels:
Experimental: false
Insecure Registries:
 127.0.0.0/8
Live Restore Enabled: false

Additional environment details (AWS, VirtualBox, physical, etc.)

[tgaff]

+1 This would be really useful. I'd like to pull a tag based off of a specific branch if it exists and if not I'll just pull the :latest

To do that I'd have a script that does something like:

if $(docker tag -r company/product:my_tag); then
  docker pull company/product:my_tag
else
  docker pull company/product:latest
fi

That being said, I think perhaps this ticket needs to be migrated to docker/cli since this is a cli issue.

[seemethere]

You can use docker manifest inspect to do this.

if docker manifest inspect company/product:my_tag >/dev/null 2>&1; then
	# do stuff
fi

[winny-]

Can docker manifest list tags for an image on the registry? (Without pulling all the images?)

[seemethere]

Oh no it can only check the existence of one image / manifest list

[tgaff]

Doesn't it also require you to edit a config file and enable experimental mode on any machines that might run this? Definitely I can do that locally but I'm not sure about everywhere else.

[seemethere]

@tgaff You can use an environmental variable to set that as of 18.06 with DOCKER_CLI_EXPERIMENTAL, the feature is still marked as experimental but we heavily use it internally with the environment variable set.

[mdeknowis]

Also it would be great to find the tags pointing to the same image. E.g. I want to identify the tags, which are also pointing to the same image as latest. So I can use that one, and log and add this information to the process, and know later on much better, which docker image was used, even if I want to use always the latest one.

[mrchapp]

Related use case: https://github.com/docker/cli/issues/836

[sabik]

Related StackOverflow answer: How to pull all alternative tags of a docker image?

[sabik]

Also it would be great to find the tags pointing to the same image. E.g. I want to identify the tags, which are also pointing to the same image as latest.

+1

We deploy images by digest, for stability and repeatability, periodically updating the digest by running docker pull nginx:latest followed by docker inspect --format='{{index .RepoDigests 0}}' nginx:latest (then creating a PR if there's any change). Unfortunately, that means we only have the word "latest" and the digest when reviewing the upgrade; being able to retrieve that the image is also tagged "1.19.6" would be excellent in reviewing the upgrade (particularly to see if it's major, minor or patch-level upgrade) and in diagnosing any failures.

[thaJeztah]

If you have Docker Desktop installed, you can use the hub-tool utility that's currently in preview (still beta, and both UX and name will likely change); https://www.docker.com/blog/docker-hub-experimental-cli-tool/

$ hub-tool tag ls --sort updated nginx

TAG                           DIGEST                                                                     STATUS    LAST UPDATE      LAST PUSHED    LAST PULLED       SIZE
nginx:stable-alpine-perl      sha256:0c85226446a083d92fbf432faee51d12933eafdcf13eb0b7d06fc465368ae908    active    2 weeks ago      2 weeks        3 minutes         124.8MB
nginx:stable-alpine           sha256:da3716611fb965f3fda1f3281882baeb2760ca8bb7317f1d22ed45e75570827b    active    2 weeks ago      2 weeks        5 minutes         64.99MB
nginx:mainline-alpine-perl    sha256:65f87cf0859fc1de79c1346ce9b7b7ecb4abb6042339a6b696fc08309453d74c    active    2 weeks ago      2 weeks        21 minutes        126.3MB
nginx:mainline-alpine         sha256:55533d629d34a30401be42a186c2d7f6338feb808e42a3b40f40faf3f99b5596    active    2 weeks ago      2 weeks        2 minutes         66.49MB
nginx:alpine-perl             sha256:4737b313d0297ec1a570279002be57c4440ba229b6937a9a3e54775823d3f17f    active    2 weeks ago      2 weeks        21 minutes        126.3MB
nginx:alpine                  sha256:50bf829ce093e6a1b5e244a9017bb8679590344332f01f8d1eb947877c9a3694    active    2 weeks ago      2 weeks        2 minutes         66.49MB
nginx:1.19.6-alpine-perl      sha256:63a230880775f228250a85db638626f1d5c323bbf4b18014dd2e0e9f616ee746    active    2 weeks ago      2 weeks        21 minutes        126.3MB
nginx:1.19.6-alpine           sha256:336994e7a9b771908b905b1c0124e11895780b0e3af50075a2014063b3292bfd    active    2 weeks ago      2 weeks        2 minutes         66.49MB
nginx:1.19-alpine-perl        sha256:e431b86f520afaf3e800e15b428e969f67eecb34b85bae5c25fbc0bddf519ce2    active    2 weeks ago      2 weeks        21 minutes        126.3MB
nginx:1.19-alpine             sha256:50bf829ce093e6a1b5e244a9017bb8679590344332f01f8d1eb947877c9a3694    active    2 weeks ago      2 weeks        2 minutes         66.49MB
nginx:1.18.0-alpine-perl      sha256:b2c101d2a7dbe9a3aa31b59a73ae9fb7dcf768502eebc75ffd61345b166271f4    active    2 weeks ago      2 weeks        3 minutes         124.8MB
nginx:1.18.0-alpine           sha256:52e7d61873346c887de8258923a52e3f06a2f8e84caa8c9133376acd00c8da13    active    2 weeks ago      2 weeks        5 minutes         64.99MB
nginx:1.18-alpine-perl        sha256:b2c101d2a7dbe9a3aa31b59a73ae9fb7dcf768502eebc75ffd61345b166271f4    active    2 weeks ago      2 weeks        3 minutes         124.8MB
nginx:1.18-alpine             sha256:a41846b6a41f298784b7dd9925d0b6649794d47244fe01e17b7f9ad8af344494    active    2 weeks ago      2 weeks        5 minutes         64.99MB
nginx:1-alpine-perl           sha256:71c78821092dcb3764fae2d1e6d78fc38417f7dc486451125efaa06563165a44    active    2 weeks ago      2 weeks        21 minutes        126.3MB
nginx:1-alpine                sha256:d152c79d06eeb7d7acd4041f47b8c71ef93e52b2f6fa70aee4e0fc365bdc475d    active    2 weeks ago      2 weeks        2 minutes         66.49MB
nginx:perl                    sha256:b7d135f454cb7e64cc0189b23dca7c72523689db7245f2bc381782b30c4bbade    active    3 weeks ago      3 weeks        9 minutes         506.4MB
nginx:mainline-perl           sha256:29934d835af32d2af4156df8676d420e0471234634f42c2a241f62fdd79c9278    active    3 weeks ago      3 weeks        9 minutes         506.4MB

...

[batagy]

Hi,

The "hub-tool" can be used also for Private docker registries , like jFrog docker registry in a company? Or this handles only Docker Hub at https://hub.docker.com/ ?

Thanks in advance