[docker] How to get a list of images on docker registry v2

I'm using docker registry v1 and I'm interested in migrating to the newer version, v2. But I need some way to get a list of images present on registry; for example with registry v1 I can execute a GET request to http://myregistry:5000/v1/search? and the result is:

{
  "num_results": 2,
  "query": "",
  "results": [
    {
      "description": "",
      "name": "deis/router"
    },
    {
      "description": "",
      "name": "deis/database"
    }
  ]
}

But I can't find on official documentation something similar to get a list of image on registry. Anybody knows a way to do it on new version v2?

I wrote an easy-to-use command line tool for listing images in various ways (like list all images, list all tags of those images, list all layers of those tags).

It also allows you to delete unused images in various ways, like delete only older tags of a single image or from all images etc. This is convenient when you are filling your registry from a CI server and want to keep only latest/stable versions.

It is written in python and does not need you to download bulky big custom registry images.

This has been driving me crazy, but I finally put all the pieces together. As of 1/25/2015, I've confirmed that it is possible to list the images in the docker V2 registry ( exactly as @jonatan mentioned, above. )

I would up-vote that answer, if I had the rep for it.

Instead, I'll expand on the answer. Since registry V2 is made with security in mind, I think it's appropriate to include how to set it up with a self signed cert, and run the container with that cert in order that an https call can be made to it with that cert:

This is the script I actually use to start the registry:

sudo docker stop registry
sudo docker rm -v registry
sudo docker run -d \
  -p 5001:5001 \
  -p 5000:5000 \
  --restart=always \
  --name registry \
  -v /data/registry:/var/lib/registry \
  -v /root/certs:/certs \
  -e REGISTRY_HTTP_TLS_CERTIFICATE=/certs/domain.crt \
  -e REGISTRY_HTTP_TLS_KEY=/certs/domain.key \ 
  -e REGISTRY_HTTP_DEBUG_ADDR=':5001' \
  registry:2.2.1

This may be obvious to some, but I always get mixed up with keys and certs. The file that needs to be referenced to make the call @jonaton mentions above**, is the domain.crt listed above. ( Since I put domain.crt in /root, I made a copy into the user directory where it could be accessed. )

curl --cacert ~/domain.crt https://myregistry:5000/v2/_catalog
> {"repositories":["redis","ubuntu"]}

**The command above has been changed: -X GET didn't actually work when I tried it.

Note: https://myregistry:5000 ( as above ) must match the domain given to the cert generated.

I had to do the same here and the above works except I had to provide login details as it was a local docker repository.

It is as per the above but with supplying the username/password in the URL.

curl -k -X GET https://yourusername:yourpassword@theregistryURL/v2/_catalog

It comes back as unformatted JSON.

I piped it through the python formatter for ease of human reading, in case you would like to have it in this format.

curl -k -X GET https://yourusername:yourpassword@theregistryURL/v2/_catalog | python -m json.tool

The latest version of Docker Registry available from https://github.com/docker/distribution supports Catalog API. (v2/_catalog). This allows for capability to search repositories

If interested, you can try docker image registry CLI I built to make it easy for using the search features in the new Docker Registry distribution (https://github.com/vivekjuneja/docker_registry_cli)

We wrote a CLI tool for this purpose: docker-ls It allows you to browse a docker registry and supports authentication via token or basic auth.

Since each registry runs as a container the container ID has an associated log file ID-json.log this log file contains the vars.name=[image] and vars.reference=[tag]. A script can be used to extrapolate and print these. This is perhaps one method to list images pushed to registry V2-2.0.1.

Install registry:2.1.1 or later (you can check the last one, here) and use GET /v2/_catalog to get list.

https://github.com/docker/distribution/blob/master/docs/spec/api.md#listing-repositories

Lista all images by Shell script example: https://gist.github.com/OndrejP/a2386d08e5308b0776c0

If some on get this far.

Taking what others have already said above. Here is a one-liner that puts the answer into a text file formatted, json.

curl "http://mydocker.registry.domain/v2/_catalog?n=2000" | jq . - > /tmp/registry.lst

This looks like

{
  "repositories": [
    "somerepo/somecontiner",
    "somerepo_other/someothercontiner",
 ...
  ]
}

You might need to change the `?n=xxxx' to match how many containers you have.

Next is a way to automatically remove old and unused containers.

Get catalogs

Default, registry api return 100 entries of catalog, there is the code:

When you curl the registry api:

curl --cacert domain.crt https://your.registry:5000/v2/_catalog

it equivalents with:

curl --cacert domain.crt https://your.registry:5000/v2/_catalog?n=100

This is a pagination methond.

When the sum of entries beyond 100, you can do in two ways:

First: give a bigger number

curl --cacert domain.crt https://your.registry:5000/v2/_catalog?n=2000

Sencond: parse the next linker url

curl --cacert domain.crt https://your.registry:5000/v2/_catalog

A link element contained in response header:

curl --cacert domain.crt https://your.registry:5000/v2/_catalog

response header:

Link: </v2/_catalog?last=pro-octopus-ws&n=100>; rel="next"

The link element have the last entry of this request, then you can request the next 'page':

curl --cacert domain.crt https://your.registry:5000/v2/_catalog?last=pro-octopus-ws

If the response header contains link element, you can do it in a loop.

Get Images

When you get the result of catalog, it like follows:

{ "repositories": [ "busybox", "ceph/mds" ] }

you can get the images in every catalog:

curl --cacert domain.crt https://your.registry:5000/v2/busybox/tags/list

returns:

{"name":"busybox","tags":["latest"]}

Using "/v2/_catalog" and "/tags/list" endpoints you can't really list all the images. If you pushed a few different images and tagged them "latest" you can't really list the old images! You can still pull them if you refer to them using digest "docker pull ubuntu@sha256:ac13c5d2...". So the answer is - there is no way to list images you can only list tags which is not the same

Docker search registry v2 functionality is currently not supported at the time of this writing. See discussion since Feb 2015: "propose registry search functionality #206" https://github.com/docker/distribution/issues/206

I wrote a script, view-private-registry, that you can find: https://github.com/BradleyA/Search-docker-registry-v2-script.1.0 It is not pretty but it gets the information needed from the private registry.

Example of output from view-private-registry:

$ view-private-registry`
busybox:latest
gcr.io/google_containers/etcd:2.0.9
gcr.io/google_containers/hyperkube:v0.21.2
gcr.io/google_containers/pause:0.8.0
google/cadvisor:latest
jenkins:latest
logstash:latest
mongo:latest
nginx:latest
python:2.7
redis:latest
registry:2.1.1
stackengine/controller:latest
tomcat:7
tomcat:latest
ubuntu:14.04.2
Number of images:   16
Disk space used:    1.7G    /mnt/three/docker-registry/registry-data

you can search on

http://<ip/hostname>:<port>/v2/_catalog

Here's an example that lists all tags of all images on the registry. It handles a registry configured for HTTP Basic auth too.

THE_REGISTRY=localhost:5000

# Get username:password from docker configuration. You could
# inject these some other way instead if you wanted.
CREDS=$(jq -r ".[\"auths\"][\"$THE_REGISTRY\"][\"auth\"]" .docker/config.json | base64 -d)

curl -s --user $CREDS https://$THE_REGISTRY/v2/_catalog | \
    jq -r '.["repositories"][]' | \
    xargs -I @REPO@ curl -s --user $CREDS https://$THE_REGISTRY/v2/@REPO@/tags/list | \
    jq -M '.["name"] + ":" + .["tags"][]'

Explanation:

• extract username:password from .docker/config.json
• make a https request to the registry to list all "repositories"
• filter the json result to a flat list of repository names
• for each repository name:
• make a https request to the registry to list all "tags" for that "repository"
• filter the stream of result json objects, printing "repository":"tag" pairs for each tag found in each repository

Here is a nice little one liner (uses JQ) to print out a list of Repos and associated tags.

If you dont have jq installed you can use: brew install jq

# This is my URL but you can use any
REPO_URL=10.230.47.94:443

curl -k -s -X GET https://$REPO_URL/v2/_catalog \
 | jq '.repositories[]' \
 | sort \
 | xargs -I _ curl -s -k -X GET https://$REPO_URL/v2/_/tags/list

This threads dates back a long time, the most recents tools that one should consider are skopeo and crane.

skopeo supports signing and has many other features, while crane is a bit more minimalistic and I found it easier to integrate with in a simple shell script.