Delete docker images from nexus registry using api - docker

There's a nexus setup running for docker registry. I'm struggling to delete old/unnecessary images from nexus setup using the APIs.So far I'm aware of below available APIs. There are 2 requirements:
Delete images older than 30 days.
Keep at least 5 tags of each image.
The delete api can only delete using the digest of the images but I"m not sure how to find exact one for the tags of images. Search api don't seem to work for docker images. Can someone please help?
## Search api
https://help.sonatype.com/repomanager3/integrations/rest-and-integration-api/search-api?_ga=2.253346826.2007475959.1640178248-1042170715.1640178248#SearchAPI-SearchComponents
## Find all catalog images under docker registery
curl -u admin:adminPass -X "GET" nexus.example.com/v2/_catalog | jq
## Get all tags of an image
curl -u admin:adminPass -X "GET" nexus.example.com/v2/abc-web-service-prod/tags/list
## Get manifests
curl -u admin:adminPass -X "GET" "nexus.example.com/v2/abc-web-service-stage-2/manifests/5.2.6_1" | jq
## Delete by digest
curl -i -u admin:adminPass -X "DELETE" "nexus.example.com/v2/abc-web-service/manifests/sha256:8829ce7278c1151f61438dcfea20e3694fee2241a75737e3a8de31a27f0014a5"

Two things are missing from the "get manifests" example. First, if you include the http headers, you'll likely get the digest field, or you can skip the jq and pipe the result into a sha256sum to get the digest. But you also need to add an "Accept" header for the various media types of a manifest, otherwise the registry will convert it to an older schema v1 syntax which will not have the same digest. Here's an example that does the two v2 docker media types:
api="application/vnd.docker.distribution.manifest.v2+json"
apil="application/vnd.docker.distribution.manifest.list.v2+json"
curl -H "Accept: ${api}" -H "Accept: ${apil}" \
-u admin:adminPass \
-I -s "nexus.example.com/v2/abc-web-service-stage-2/manifests/5.2.6_1"
The next issue you'll run into with your policy is the 30 day requirement. You can get the creation time on many images by pulling their image config blob (it's listed in the manifest), but that date will be when the image was created, not when it was pushed or last pulled. There have been suggestions to add API's to OCI to handle more metadata, but we're still a ways off from that, and further still to get registry providers to implement them. So you'd end up deleting things that are likely being used. Even the 5 tag rule can be problematic if several new tags are created working through bugs in CI and you age out the image currently deployed in production.
With that all said, some tooling that I work on called regclient may help. The regctl command gives you a way to script this in a shell, e.g.:
#!/bin/sh
registry="nexus.example.com"
cutoff="$(date -d -30days '+%s')"
for repo in $(regctl repo ls "$registry"); do
# The "head -n -5" ignores the last 5 tags, but you may want to sort that list first.
for tag in $(regctl tag ls "$registry/$repo" | head -n -5); do
# This is the most likely command to fail since the created timestamp is optional, may be set to 0,
# and the string format might vary.
# The cut is to remove the "+0000" that breaks the "date" command.
created="$(regctl image config "$registry/$repo:$tag" --format '{{.Created}}' | cut -f1,2,4 -d' ')"
createdSec="$(date -d "$created" '+%s')"
# both timestamps are converted to seconds since epoc, allowing numeric comparison
if [ "$createdSec" -lt "$cutoff" ]; then
# next line is prefixed with echo for debugging, delete the echo to run the tag delete command
echo regctl tag rm "$registry/$repo:$tag"
fi
done
done
Note that I'm using "regctl tag rm" above, which is different from an image manifest delete you're seeing in the API. This will attempt to do an OCI tag delete API first, which likely isn't supported by your registry. It falls back to pushing a dummy manifest and deleting that. The alternative of deleting the current manifest the tag points to is you may delete more tags than intended (you could have 5 tags all pointing to the same manifest).
If you want to further automate this, regbot in that same repo lets you build a policy and run it on a schedule to constantly cleanup old images according to your rules.
In addition to regclient, there's also crane and skopeo that may also help in this space, but the features of each of these will vary.

I found a great solution to this.
https://github.com/andrey-pohilko/registry-cli
1. Create a docker image [name: registry-cli:1.0.1] using below Dockerfile
ADD requirements-build.txt /
RUN pip install -r /requirements-build.txt
ADD registry.py /
ENTRYPOINT ["/registry.py"]
2. Use below command to list down all images:tags in your private nexus registry.
docker run --rm registry-cli:1.0.1 -l admin:adminPass -r http://nexus.example.com
3. To get all tags of a particular image.
docker run --rm registry-cli:1.0.1 -l admin:adminPass -r http://nexus.example.com-i <name-of-the-image1> <name-of-the-image2>
4. To delete all old tags of a particular image but keep latest 10 tags.
docker run --rm registry-cli:1.0.1 -l admin:adminPass -r http://nexus.example.com -i <name-of-the-image1> --delete
5. To delete all the old tags of all the images in the repository but keep 10 latest tags of each image
docker run --rm registry-cli:1.0.1 -l admin:adminPass -r http://nexus.example.com --delete
6. If you wish to keep 20 images instead of 10 then use --num
docker run --rm registry-cli:1.0.1 -l admin:adminPass -r http://nexus.example.com --delete --num 20
7. Once you're done deleting the older tags of the images, run task "delete unused manifests and docker images"
8. Post step:7, run compaction task to reclaim the storage.

Related

How to find a container image tag/label from its hash

I have a use case I need to find the image tag from its hashed format.
for example, if I have this image
quay.io/containerdisks/centos-stream#sha256:0c8d8b253a0b729c602efe45a5bc4640b3d4161b6924db3def2e7a76296e42c9
I would like to find one or more labels that point to this image.
At the moment the only option I know of is to "brute-force" it by fetching all the labels related to this image and checking the digest of each against the hash I'm looking for.
Is there another option?
The tag listing only includes tags, not the digests for each of those tags (though I'd like to see that improved). So you're left with brute forcing a digest check against each tag. With regctl that looks like:
for tag in $(regctl tag ls quay.io/containerdisks/centos-stream); do
echo "${tag}: $(regctl image digest quay.io/containerdisks/centos-stream:${tag})"
done | grep "sha256:0c8"
Which lists the following matches:
9: sha256:0c8d8b253a0b729c602efe45a5bc4640b3d4161b6924db3def2e7a76296e42c9
9-20220829.0: sha256:0c8d8b253a0b729c602efe45a5bc4640b3d4161b6924db3def2e7a76296e42c9
9-2209010207: sha256:0c8d8b253a0b729c602efe45a5bc4640b3d4161b6924db3def2e7a76296e42c9
Note that the image digest command here only runs a HEAD request to the registry, so it doesn't download the image and should be relatively fast.
Another iteration on #BMitch answer is to use the parallel to make several queries in parallel, which reduces the time to query all the tags.
skopeo list-tags docker://quay.io/containerdisks/centos-stream \
| jq -r '.Tags[]' \
| parallel bash -c "\"printf \"%-16s\" {} '-> ' && skopeo inspect -n docker://quay.io/containerdisks/centos-stream:{} --format '{{ .Digest }}'\"" \
| grep 'sha256:0c8'

How to delete old image that created in build process automaticly?

I have a ci/cd automation in my project with gitlab, and after push my code on master branch, gitlab runner create a new docker image on my server and set latest commit hash as tag on that image, and recreate container with new image. after a while, there is a lot of unused image, and I want to delete them automaticly.
I delete old image manually.
This is my Makefile
NAME := farvisun/javabina
TAG := $$(git log -1 --pretty=%h)
IMG := ${NAME}:${TAG}
LATEST := ${NAME}:latest
app_build:
docker build -t ${IMG} -f javabina.dockerfile . && \
docker tag ${IMG} ${LATEST}
app_up:
docker-compose -p farvisun-javabina up -d javabina
And after all of this, I want a simple bash code, or other tools, to delete unused image, for example keep 3 lastest image, or keep last 2 day past builds, and delete others.
If you are fine with keeping a single image, you can use docker image prune -f, which will remove all images but the ones associated with a container, so if you run this command while the container is running, it will remove the rest of the images.
Don't forget to run docker system prune every often as well to further reduce storage usage.
In your situation where you need to keep more than one image, you can try this:
#!/bin/bash
for tag in $(docker image ls | sed 1,4d | awk '{print $3}')
do
docker image rm -f $tag
done
The first line will list all docker images, remove from the list the first 3 ones which you want to keep, and select only the column with the image ID. Then, for each of the IDs, we remove the image.
If you want to remove more, change the 4d for another number. Notice that the first line is a header, so it must always be removed.
If you want to filter the images by a tag first, you can make your own filters.
You can schedule (e.g. once a day or once a week) in the compilation machine a "docker image prune" command.
https://docs.docker.com/engine/reference/commandline/image_prune/
Here is a way we can remove old images, after a new successful build in our pipeline
# build
- docker build -t APP_NAME:$(git describe --tags --no-abbrev) .
# docker tag
- docker tag APP_NAME:$(git describe --tags --no-abbrev) artifactory.XYZ.com/APP_NAME:latest
# remote old images
- sha=$(docker image inspect artifactory.XYZ.com/APP_NAME:latest -f '{{.ID}}')
- image_sha=$(echo $sha | cut -d':' -f2)
- image_id=$(echo $image_sha | head -c 12)
- docker image ls | grep APP_NAME | while read name tag id others; do if ! [ $id = $image_id ]; then docker image rm --force $id; fi ; done

delete image from docker registry v2

the Docker Registry v2 has an API endpoint to delete an image
DELETE /v2/<name>/manifests/<reference>
https://github.com/docker/distribution/blob/master/docs/spec/api.md#deleting-an-image
However the doc says:
For deletes, reference must be a digest or the delete will fail.
Indeed, using a tag does not work and returns a 405 Operation Not Supported
The problem is, there doesn't seem to be any endpoint to get the digest of an image.
The endpoints to list images, and tags only list those.
Trying to get the manifest with
GET /v2/<name>/manifests/<reference>
using the tag as <reference>I see that a Docker-Content-Digest header is set with a digest which the doc says is
Docker-Content-Digest: Digest of the targeted content
for the request.
while the body contains a bunch of blobSum: <digest>
If I try using the Header digest value, with
GET /v2/<name>/manifests/<reference>
and the digest as <reference>, I get a 404.
the digest looks like: sha256:6367f164d92eb69a7f4bf4cab173e6b21398f94984ea1e1d8addc1863f4ed502
and I tried with and without the sha256 prefix. but no luck
So how am I supposed to get the digest of the image I want to delete, to delete it?
curl -u login:password -H "Accept: application/vnd.docker.distribution.manifest.v2+json" -X GET https://registry.private.com/v2/<name>/manifests/<tag>
json > config > digest
Not a trivial operation in Docker API right now but I hope this procedure helps:
Create a file and give it a name, for me it will be delete-image.sh:
#!/bin/bash
# Inspired by: https://gist.github.com/jaytaylor/86d5efaddda926a25fa68c263830dac1
set -o errexit
if [ -z "$1" ]
then
echo "Error: The image name arg is mandatory"
exit 1
fi
registry='localhost:5000'
name=$1
curl -v -sSL -X DELETE "http://${registry}/v2/${name}/manifests/$(
curl -sSL -I \
-H "Accept: application/vnd.docker.distribution.manifest.v2+json" \
"http://${registry}/v2/${name}/manifests/$(
curl -sSL "http://${registry}/v2/${name}/tags/list" | jq -r '.tags[0]'
)" \
| awk '$1 == "Docker-Content-Digest:" { print $2 }' \
| tr -d $'\r' \
)"
Give the permission to that file so that it can be executed;
sudo chmod u+x ./delete-image.sh
./delete-image.sh <your-image-name>
After deleting the image, collect the garbage;
docker exec -it registry.localhost bin/registry \
garbage-collect /etc/docker/registry/config.yml
Now delete the folder for that image (and I'm assuming that you created a volume previously);
sudo rm -rf ${HOME}/registry/docker/registry/v2/repositories/<your-image-name>
If you have not created a volume, you may have to enter the container to delete that folder. But, in any case, it's a good idea to restart the container;
docker restart registry.localhost
Procedure not recommended for production environments.
I hope that we will have better support for these operations natively in the Docker API in the future.

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?
For the latest (as of 2015-07-31) version of Registry V2, you can get this image from DockerHub:
docker pull distribution/registry:master
List all repositories (effectively images):
curl -X GET https://myregistry:5000/v2/_catalog
> {"repositories":["redis","ubuntu"]}
List all tags for a repository:
curl -X GET https://myregistry:5000/v2/ubuntu/tags/list
> {"name":"ubuntu","tags":["14.04"]}
If the registry needs authentication you have to specify username and password in the curl command
curl -X GET -u <user>:<pass> https://myregistry:5000/v2/_catalog
curl -X GET -u <user>:<pass> https://myregistry:5000/v2/ubuntu/tags/list
you can search on
http://<ip/hostname>:<port>/v2/_catalog
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
Second: 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"]}
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)
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.
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.
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
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
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
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
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
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.
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.
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.
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
One liner bash to list all images with their tags:
curl --user user:pass https://myregistry.com/v2/_catalog | jq .repositories | sed -n 's/[ ",]//gp' | xargs -L1 -IIMAGE curl -s --user user:pass https://myregistry.com/v2/IMAGE/tags/list | jq '. as $parent | .tags[] | $parent.name + ":" + . '
Two lines to search for something in the image name:
search=my_container_part_name
curl --user user:pass https://registry.medworx.io/v2/_catalog | jq .repositories | sed -n '/'"$search"'/{s/[ ",]//gp;}' | xargs -L1 -IIMAGE curl -s --user user:pass https://registry.medworx.io/v2/IMAGE/tags/list | jq '. as $parent | .tags[] | $parent.name + ":" + . '
replace: user, pass and myregistry.com accordingly
uses curl, sed, xargs and jq and is hard to understand... but it does the job. It produces one call per image + 1.
If you can ssh or attach to the docker registry container, just browse the filesystem to look for things you want, like:
kubectl exec -it docker-registry-0 -- /bin/sh
ls /var/lib/registry/docker/registry/v2/repositories
ls /var/lib/registry/docker/registry/v2/repositories/busybox/_manifests/tags/
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.
If your use-case is identifying only SIGNED and TRUSTED images for production, then this method is handy.
It parses a docker image repo for all SIGNED tags and strips away all the JSON formatting, puking-out only clean image tags. Which of course can be processed further according to your requirements.
Format of Command:
docker trust inspect imageName | grep "SignedTag" | awk -F'"' '{print $4}'
Examples using the nginx & Bitnami Docker repos:
docker trust inspect nginx | grep "SignedTag" | awk -F'"' '{print $4}'
docker trust inspect bitnami/java | grep "SignedTag" | awk -F'"' '{print $4}'
If there are no signed images then No signatures or cannot access imageName will be returned.
Example of a repo WITHOUT signed images (at the time of this writing) using the Wordpress Docker repo:
docker trust inspect wordpress | grep "SignedTag" | awk -F'"' '{print $4}'
If you want a nice web interface to your registry you can use this registry-browser docker image. This is useful if you just want to look around your registry, different repositories and tags.
If, the accepted answer here only returns a blank line, it is likely because of your ssl/tls cert on your registry server. Use the --insecure flag:
curl --insecure https://<registryHostnameOrIP>:5000/v2/_catalog

How to delete images from a private docker registry?

I run a private docker registry, and I want to delete all images but the latest from a repository. I don't want to delete the entire repository, just some of the images inside it. The API docs don't mention a way to do this, but surely it's possible?
Currently you cannot use the Registry API for that task. It only allows you to delete a repository or a specific tag.
In general, deleting a repository means, that all the tags associated to this repo are deleted.
Deleting a tag means, that the association between an image and a tag is deleted.
None of the above will delete a single image. They are left on your disk.
Workaround
For this workaround you need to have your docker images stored locally.
A workaround for your solution would be to delete all but the latest tags and thereby potentially removing the reference to the associated images. Then you can run this script to remove all images, that are not referenced by any tag or the ancestry of any used image.
Terminology (images and tags)
Consider an image graph like this where the capital letters (A, B, ...) represent short image IDs and <- means that an image is based on another image:
A <- B <- C <- D
Now we add tags to the picture:
A <- B <- C <- D
| |
| <version2>
<version1>
Here, the tag <version1> references the image C and the tag <version2> references the image D.
Refining your question
In your question you said that you wanted to remove
all images but the latest
. Now, this terminology is not quite correct. You've mixed images and tags. Looking at the graph I think you would agree that the tag <version2> represents the latest version. In fact, according to this question you can have a tag that represents the latest version:
A <- B <- C <- D
| |
| <version2>
| <latest>
<version1>
Since the <latest> tag references image D I ask you: do you really want to delete all but image D? Probably not!
What happens if you delete a tag?
If you delete the tag <version1> using the Docker REST API you will get this:
A <- B <- C <- D
|
<version2>
<latest>
Remember: Docker will never delete an image! Even if it did, in this case it cannot delete an image, since the image C is part of the ancestry for the image D which is tagged.
Even if you use this script, no image will be deleted.
When an image can be deleted
Under the condition that you can control when somebody can pull or push to your registry (e.g. by disabling the REST interface). You can delete an image from an image graph if no other image is based on it and no tag refers to it.
Notice that in the following graph, the image D is not based on C but on B. Therefore, D doesn't depend on C. If you delete tag <version1> in this graph, the image C will not be used by any image and this script can remove it.
A <- B <--------- D
\ |
\ <version2>
\ <latest>
\ <- C
|
<version1>
After the cleanup your image graph looks like this:
A <- B <- D
|
<version2>
<latest>
Is this what you want?
I've faced the same problem with my registry, then I tried the solution listed below from a blog page. It works.
Do note, the deletion must be enabled for it to work. You can do it by providing a custom config, or by setting REGISTRY_STORAGE_DELETE_ENABLED=true.
Step 1: List the repositories
$ curl -sS <domain-on-ip>:5000/v2/_catalog
The response will be in the following format:
{
"repositories": [
<repo>,
...
]
}
Step 2: List the repository tags
$ curl -sS <domain-on-ip>:5000/v2/<repo>/tags/list
The response will be in the following format:
{
"name": <repo>,
"tags": [
<tag>,
...
]
}
Step 3: Determine the digest of the target tag
$ curl -sS -H 'Accept: application/vnd.docker.distribution.manifest.v2+json' \
-o /dev/null \
-w '%header{Docker-Content-Digest}' \
<domain-or-ip>:5000/v2/<repo>/manifests/<tag>
Do note, the Accept header is needed here. Without it you'll get a different value and the deletion will fail.
The response will be in the following format:
sha256:6de813fb93debd551ea6781e90b02f1f93efab9d882a6cd06bbd96a07188b073
Step 4: Delete the manifest
$ curl -sS -X DELETE <domain-or-ip>:5000/v2/<repo>/manifests/<digest>
Step 5: Garbage collect the image
Run this command in your docker registry container:
$ registry garbage-collect /etc/docker/registry/config.yml
Here is my config.yml:
version: 0.1
log:
fields:
service: registry
storage:
cache:
blobdescriptor: inmemory
filesystem:
rootdirectory: /var/lib/registry
delete:
enabled: true
http:
addr: :5000
headers:
X-Content-Type-Options: [nosniff]
health:
storagedriver:
enabled: true
interval: 10s
threshold: 3
The current v2 registry now supports deleting via DELETE /v2/<name>/manifests/<reference>.
See: https://github.com/docker/distribution/blob/master/docs/spec/api.md#deleting-an-image
The <reference> can be taken from the Docker-Content-Digest header of a GET /v2/<name>/manifests/<tag> request (do note that the Accept: application/vnd.docker.distribution.manifest.v2+json header is needed for this request).
A script that makes use of it: https://github.com/byrnedo/docker-reg-tool
For it to work deletion must be enabled (REGISTRY_STORAGE_DELETE_ENABLED=true).
And to really free the disk space you need to run garbage collection.
Problem 1
You mentioned it was your private docker registry, so you probably need to check Registry API instead of Hub registry API doc, which is the link you provided.
Problem 2
docker registry API is a client/server protocol, it is up to the server's implementation on whether to remove the images in the back-end. (I guess)
DELETE /v1/repositories/(namespace)/(repository)/tags/(tag*)
Detailed explanation
Below I demo how it works now from your description as my understanding for your questions.
I run a private docker registry.
I use the default one, and listen on port 5000.
docker run -d -p 5000:5000 registry
Then I tag the local image and push into it.
$ docker tag ubuntu localhost:5000/ubuntu
$ docker push localhost:5000/ubuntu
The push refers to a repository [localhost:5000/ubuntu] (len: 1)
Sending image list
Pushing repository localhost:5000/ubuntu (1 tags)
511136ea3c5a: Image successfully pushed
d7ac5e4f1812: Image successfully pushed
2f4b4d6a4a06: Image successfully pushed
83ff768040a0: Image successfully pushed
6c37f792ddac: Image successfully pushed
e54ca5efa2e9: Image successfully pushed
Pushing tag for rev [e54ca5efa2e9] on {http://localhost:5000/v1/repositories/ubuntu/tags/latest}
After that I can use Registry API to check it exists in your private docker registry
$ curl -X GET localhost:5000/v1/repositories/ubuntu/tags
{"latest": "e54ca5efa2e962582a223ca9810f7f1b62ea9b5c3975d14a5da79d3bf6020f37"}
Now I can delete the tag using that API !!
$ curl -X DELETE localhost:5000/v1/repositories/ubuntu/tags/latest
true
Check again, the tag doesn't exist in my private registry server
$ curl -X GET localhost:5000/v1/repositories/ubuntu/tags/latest
{"error": "Tag not found"}
This is really ugly but it works, text is tested on registry:2.5.1.
I did not manage to get delete working smoothly even after updating configuration to enable delete. The ID was really difficult to retrieve, had to login to get it, maybe some misunderstanding. Anyway, the following works:
Enter the container
docker exec -it registry sh
Define variables matching your container and container version:
export NAME="google/cadvisor"
export VERSION="v0.24.1"
Move to the the registry directory:
cd /var/lib/registry/docker/registry/v2
Delete files related to your hash:
find . | grep `ls ./repositories/$NAME/_manifests/tags/$VERSION/index/sha256`| xargs rm -rf $1
Delete manifests:
rm -rf ./repositories/$NAME/_manifests/tags/$VERSION
Logout
exit
Run the GC:
docker exec -it registry bin/registry garbage-collect /etc/docker/registry/config.yml
If all was done properly some information about deleted blobs is shown.
There are some clients (in Python, Ruby, etc) which do exactly that. For my taste, it isn't sustainable to install a runtime (e.g. Python) on my registry server, just to housekeep my registry!
So deckschrubber is my solution:
go install github.com/fraunhoferfokus/deckschrubber#latest
$GOPATH/bin/deckschrubber
images older than a given age are automatically deleted. Age can be specified using -year, -month, -day, or a combination of them:
$GOPATH/bin/deckschrubber -month 2 -day 13 -registry http://registry:5000
UPDATE: here's a short introduction on deckschrubber.
The requirement to delete all tags except latest gets complicated because the same image manifest can be pointed to by multiple tags, so when you delete a manifest for one tag, you may effectively delete multiple tags.
There are a few options to make that workable. One is to track the digest for the latest tag and only delete manifests for other digests, or you can use some different API calls to delete the tags themselves.
Regardless of how you implement this, first your registry needs to be configured to allow the delete API's. With the minimal registry:2 image, that involves starting it with an environment variable REGISTRY_STORAGE_DELETE_ENABLED=true (or the equivalent yaml config).
Then for a simple script to loop through the tags and delete, there's:
#!/bin/sh
repo="localhost:5000/repo/to/prune"
for tag in $(regctl tag ls $repo); do
if [ "$tag" != "latest" ]; then
echo "Deleting: $(regctl image digest --list "${repo}:${tag}") [$tag]"
regctl tag rm "${repo}:${tag}"
fi
done
The regctl command used here comes from regclient and the regctl tag rm logic first attempts to perform the tag delete API added recently to the distribution-spec. Since most registries haven't implemented that spec, it falls back to the manifest delete API, but it first creates a dummy manifest to overwrite the tag, and then deletes that new digest. In doing so, if the old manifest was in use by other tags, it doesn't delete those other tags.
An alternative version of the script that deletes manifests except those pointing to the latest digest looks like:
#!/bin/sh
repo="localhost:5000/repo/to/prune"
save="$(regctl image digest --list "${repo}:latest")"
for tag in $(regctl tag ls $repo); do
digest="$(regctl image digest --list "${repo}:${tag}")"
if [ "$digest" != "$save" ]; then
echo "Deleting: $digest [$tag]"
regctl manifest rm "${repo}#${digest}"
fi
done
If you find yourself needing to create a deletion policy to automate the deleting of lots of images, I'd recommend looking at regclient/regbot from the same repo which allows you to define that policy and leave it running to continuously prune your registry.
Once the images have been deleted, you'll need to garbage collect your registry in most use cases. For example with the registry:2 image that looks like:
docker exec registry /bin/registry garbage-collect \
/etc/docker/registry/config.yml --delete-untagged
Briefly;
1) You must typed following command for RepoDigests of a docker repo;
## docker inspect <registry-host>:<registry-port>/<image-name>:<tag>
> docker inspect 174.24.100.50:8448/example-image:latest
[
{
"Id": "sha256:16c5af74ed970b1671fe095e063e255e0160900a0e12e1f8a93d75afe2fb860c",
"RepoTags": [
"174.24.100.50:8448/example-image:latest",
"example-image:latest"
],
"RepoDigests": [
"174.24.100.50:8448/example-image#sha256:5580b2110c65a1f2567eeacae18a3aec0a31d88d2504aa257a2fecf4f47695e6"
],
...
...
${digest} =
sha256:5580b2110c65a1f2567eeacae18a3aec0a31d88d2504aa257a2fecf4f47695e6
2) Use registry REST API
##curl -u username:password -vk -X DELETE registry-host>:<registry-port>/v2/<image-name>/manifests/${digest}
>curl -u example-user:example-password -vk -X DELETE http://174.24.100.50:8448/v2/example-image/manifests/sha256:5580b2110c65a1f2567eeacae18a3aec0a31d88d2504aa257a2fecf4f47695e6
You should get a 202 Accepted for a successful invocation.
3-) Run Garbage Collector
docker exec registry bin/registry garbage-collect --dry-run /etc/docker/registry/config.yml
registry — registry container name.
For more detail explanation enter link description here
Another tool you can use is registry-cli. For example, this command:
registry.py -l "login:password" -r https://your-registry.example.com --delete
will delete all but the last 10 images.
There is also a way you can remove some old images from repository just based on the date when it was created.
To do that enter your docker registry container and get the list of manifest's revisions for some specific repository:
ls -latr /var/lib/registry/docker/registry/v2/repositories/YOUR_REPO/_manifests/revisions/sha256/
The output then may be used within the request (with sha256 prefix):
curl -v --silent -H "Accept: application/vnd.docker.distribution.manifest.v2+json" -X DELETE http://DOCKER_REGISTRY_HOST:5000/v2/YOUR_REPO/manifests/sha256:OUTPUT_LINE
And of course do not forget to execute 'garbage-collect' command after that:
bin/registry garbage-collect /etc/docker/registry/config.yml
I am usually all for doing things with scripts, but if you are already running
a registry UI container built from Joxit/docker-registry-ui, I found it easier to just opt-click the delete button in the UI and delete a page of images at a time, then garbage collect after.
This docker image includes a bash script that can be used to remove images from a remote v2 registry :
https://hub.docker.com/r/vidarl/remove_image_from_registry/
Below Bash Script Deletes all the tags located in registry except the latest.
for D in /registry-data/docker/registry/v2/repositories/*; do
if [ -d "${D}" ]; then
if [ -z "$(ls -A ${D}/_manifests/tags/)" ]; then
echo ''
else
for R in $(ls -t ${D}/_manifests/tags/ | tail -n +2); do
digest=$(curl -k -I -s -H -X GET http://xx.xx.xx.xx:5000/v2/$(basename ${D})/manifests/${R} -H 'accept: application/vnd.docker.distribution.manifest.v2+json' | grep Docker-Content-Digest | awk '{print $2}' )
url="http://xx.xx.xx.xx:5000/v2/$(basename ${D})/manifests/$digest"
url=${url%$'\r'}
curl -X DELETE -k -I -s $url -H 'accept: application/vnd.docker.distribution.manifest.v2+json'
done
fi
fi
done
After this Run
docker exec $(docker ps | grep registry | awk '{print $1}') /bin/registry garbage-collect /etc/docker/registry/config.yml
Simple ruby script based on this answer: registry_cleaner.
You can run it on local machine:
./registry_cleaner.rb --host=https://registry.exmpl.com --repository=name --tags_count=4
And then on the registry machine remove blobs with /bin/registry garbage-collect /etc/docker/registry/config.yml.
Here is a script based on Yavuz Sert's answer.
It deletes all tags that are not the latest version, and their tag is greater than 950.
#!/usr/bin/env bash
CheckTag(){
Name=$1
Tag=$2
Skip=0
if [[ "${Tag}" == "latest" ]]; then
Skip=1
fi
if [[ "${Tag}" -ge "950" ]]; then
Skip=1
fi
if [[ "${Skip}" == "1" ]]; then
echo "skip ${Name} ${Tag}"
else
echo "delete ${Name} ${Tag}"
Sha=$(curl -v -s -H "Accept: application/vnd.docker.distribution.manifest.v2+json" -X GET http://127.0.0.1:5000/v2/${Name}/manifests/${Tag} 2>&1 | grep Docker-Content-Digest | awk '{print ($3)}')
Sha="${Sha/$'\r'/}"
curl -H "Accept: application/vnd.docker.distribution.manifest.v2+json" -X DELETE "http://127.0.0.1:5000/v2/${Name}/manifests/${Sha}"
fi
}
ScanRepository(){
Name=$1
echo "Repository ${Name}"
curl -s http://127.0.0.1:5000/v2/${Name}/tags/list | jq '.tags[]' |
while IFS=$"\n" read -r line; do
line="${line%\"}"
line="${line#\"}"
CheckTag $Name $line
done
}
JqPath=$(which jq)
if [[ "x${JqPath}" == "x" ]]; then
echo "Couldn't find jq executable."
exit 2
fi
curl -s http://127.0.0.1:5000/v2/_catalog | jq '.repositories[]' |
while IFS=$"\n" read -r line; do
line="${line%\"}"
line="${line#\"}"
ScanRepository $line
done
A script to remove all but the latest tag from an insecure registry (private, no auth):
#!/bin/sh -eu
repo=$1
registry=${2-localhost:5000}
tags=`curl -sS "$registry/v2/$repo/tags/list" | jq -r .tags[]`
tag2digest() {
local tag=$1
curl -sS -H 'Accept: application/vnd.docker.distribution.manifest.v2+json' \
-o /dev/null \
-w '%header{Docker-Content-Digest}' \
"$registry/v2/$repo/manifests/$tag"
}
latest_digest=`tag2digest latest`
digests=`echo "$tags" \
| while IFS= read -r tag; do
tag2digest "$tag"
echo
done \
| sort \
| uniq`
digests=`echo "$digests" \
| grep -Fvx "$latest_digest"`
echo "$digests" \
| while IFS= read -r digest; do
curl -sS -X DELETE "$registry/v2/$repo/manifests/$digest"
done
Usage:
$ ./rm-tags.sh <image> [<registry>]
After removing tags (or manifests to be more precise) run garbage collection:
$ registry garbage-collect /etc/docker/registry/config.yml
To support Docker Hub and/or auth see these answers.

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