Any feedback and comments welcome! Please use github issues for that.

Docker hub automated build: https://hub.docker.com/r/hubbitus/docker-registry-cleaner/ Instructions how to build manually see below.

Basic usage info

Direct commandline run:

$ java -jar docker-registry-cleaner-all-0.1-SNAPSHOT.jar --help
Usage: docker-registry-cleaner [options]
  Options:
    -D, --debug               Debug mode - write JSON data for got tags into debug.json file
                              Default: false
    -d, --delete              Delete old optionsByTag!
                                By default we do not delete anything. Just list applications and optionsByTag. Information about tagRegexp and its build time also provided. If there
                              any --clean options present also mark optionsByTag which supposed to be deleted.
                                For sort you may also use --sort option.
                              Default: false
    -f, --format              Format of printing tagRegexp line. See SimpleTemplateEngine description and info.hubbitus.RegistryTagInfo class for available data
                              Default: tag=[<% printf("%-" + (tag.application.length() + 1 + tags.max{ it.name.length()}.name.length()) + "s", "${tag.application}:${tag.name}")%>]; time=[${tag.created}]; isForDelete=[<%printf("%-5s", tag.keptBy.isForDelete())%>]; [${tag.keptBy}]
        --help
                              Default: false
    -i, --interactive         Interactive mode. Ask for deletion each image. Details like data and why it is proposed for delete will be shown. Implies delete = true
                              Default: false
  *     --keep                As primary goal to delete some old images we just provide some opposite rules which must be kept.
                                1) We process only applications, matches --only-applications pattern if it
                              set.
                                2) Firstly match "application" against `application` regexp
                                3) Then `tag` name against `tag` regexp
                                4) If `period` present and greater than 0 check it matches build time
                              early then in `period` (which is by default number of seconds, but suffixes m, h, d, w also supported for minutes, hours, days and weeks)
                                5) If `top` present and greater than 0,
                              from above results exempt from deletion that amount of elements, according to sorting, provided in --sort
                                6) If both `period` and `top` provided only tags *match both criteria*
                              will be kept (boolean AND)!
                                F.e.:
                                        - Said by date matched 10 tags and you have top=5 - so only 5 will be kept - other deleted
                                        - In configured date period was 10 tags and
                              you set top=20 - only 10 will be kept - other deleted

                                All other will be deleted!

                                Example of options (to provide in file, please quote properly in shell
                              options):
                                --keep=GLOBAL={ top: 5, period: 1w }
                                --keep=egaisapp=[ { tag: ".+", top: 10, period: 3d }, { tag: "release_.+", top: 4 }, {tag: "auto.+", period: "4d"} ]
                                --keep=bp-app=[ { tag:
                              "^(dev|master)$", top: 2 }, { tag: "^dev-", top: 5 }, {tag: "^master-", period: "4d"} ]
                                --keep=glrapp={ top: 4 }

                              Syntax: --keepkey=value
                              Default: {}
  * -l, --login               Docker registry login
    -o, --only-applications   Regexp to match against applications name to process. Tags for other even will not be fetched
    -p, --password            Docker registry password
    -P, --password-file       Docker registry password, stored in file for security.
  * -u, --registry-url        URL to docker registry REST endpoint. Like https://docreg.taskdata.work/v2/
        --sort                Sort method on optionsByTag list. Either "name" or "time" (build time of image, default). In case of time sorting most recent should be stay, so DESC assuming
                              Default: time

Docker run (recommended)

If you do not want develop, and just harry up to run ti, you may use docker:

docker run hubbitus/docker-registry-cleaner --usage

And real clean invocation:

docker run hubbitus/docker-registry-cleaner --registry-url 'https://docreg.taskdata.work/v2/' --login egais --keep='GLOBAL={ top: 5, period: 1w }' --password='coll-password' --delete

Instead of pass all arguments each time docker-registry-cleaner may read all arguments from file where such options placed by one on line. Look example file in test.args. In case of docker don't forget mount it inso container (--passwordFile too, if used):

docker run -v $(pwd)/run.args:/host/run.args hubbitus/docker-registry-cleaner @/run.args

Example command present in file docker.run.

Systemd service and timer planned

See issue

Build

If you wish contribute and build it himself. It si written on groovy and backed by gradle build.

Jar

Simple build executable jar (on Windows replace ./gradlew by gradlew.bat command in all examples):

./gradlew fatJar

Then you may run it in traditional way:

java -jar build/libs/docker-registry-cleaner-fat-0.1-SNAPSHOT.jar

To run tests

./gradlew check --rerun-tasks

Docker build

You have to choose one variant from:

Gradle build:

./gradlew dockerBuildImage

In that case will be generated file build/Dockerfile and docker build invoked via socket /run/docker.sock (please be sure current user have rights on it).

This method intended for convenient development.

Push also possible, but requires providing password:

DOCKER_REGISTRY_PASSWORD='cool-password' ./gradlew dockerPushImage

Traditional docker build

Intended for automatic builds on docker hub. In that case gradle invoked from Dockerfile. To make target image small used multi-stage build which require docker-ce version >= 17.

In that variant image may be built by:

docker build -t hubbitus/docker-registry-cleaner:some-tag .