Removing old / unused docker images

Question

I'm using Sonatype Nexus as a Docker Registry and after a while, it got really big (new image with every CI build and some old projects).

I tried using "Purge unused docker manifests and images" task, but it doesn't seem to do anything.

Answer 1

I remove the old docker images manuely.

1. get nexus-cli

   wget https://s3.eu-west-2.amazonaws.com/nexus-cli/1.0.0-beta/linux/nexus-cli

   chmod +x nexus-cli

2. configure host

   ./nexus-cli configure

3. show images

   ./nexus-cli image ls

4. keep the latest 5 images

   ./nexus-cli image delete -name mlabouardy/nginx -keep 5

5. A clean script

image_file=image.txt
CLI_HOME=/data/nexus3
KEEP_VERSION_NUM=5

$CLI_HOME/nexus-cli image ls > $image_file
sed -i '$d' $image_file


cat $image_file | while read line
do
    echo "start clean image:  $line"
    $CLI_HOME/nexus-cli image delete -name $line -keep $KEEP_VERSION_NUM
done

6. create create docker - delete unsued manifests and images task

7. create create admin -compact blob store task

Answer 2

You will need to setup a Cleanup Policy.

Answer 3

Create a cleaning policy (for example: 15 days after modification) - Caveat: docker push of the same hash is not modification

For each your registry (Nexus calls it "repository of type Docker"):

• Setup the cleaning policy of your choice
• The cleanup task
  • Create
  • Run until finish
  • Check the nexus3.log file
• The "remove unused manifests and images"
  • Create
  • Run until finish
  • Check the nexus3.log file
• The "compact blob" task
  • Create
  • Run until finish
  • Check the nexus3.log file
• The space should be freed now
• Don't use Nexus in your next project
• ...
• Profit

Answer 4

For removing old and / unused docker images you must use below command:

docker images purne

documents: https://docs.docker.com/engine/reference/commandline/image_prune/