cleanup docker images gitlab/gitlab-runner-helper and gitlab-runner-prebuilt-x86_64?
I'm running gitlab-ci-multi-runner on a ubuntu machine for several months now. Today i cleaned up many old docker images and noticed this:
# docker images | grep gitlab
gitlab/gitlab-runner-helper x86_64-6d06f2e 23a0614b4b27 12 days ago 50.3MB
gitlab/gitlab-runner-helper x86_64-d24b11c d4c4c7765499 4 weeks ago 50.3MB
gitlab/gitlab-runner-helper x86_64-3df822b e9635e622322 6 weeks ago 50.5MB
gitlab/gitlab-runner-helper x86_64-f018144 5cf84c90d7b1 2 months ago 42.6MB
gitlab/gitlab-runner-helper x86_64-adfc387 891c3ecc0633 2 months ago 42.6MB
gitlab/gitlab-runner-helper x86_64-6104325 e955177a0be0 3 months ago 38.7MB
gitlab/gitlab-runner-helper x86_64-0118d89 af80cfc09700 4 months ago 38.7MB
gitlab/gitlab-runner-helper x86_64-fa8b86d f889649fcdfe 4 months ago 38.7MB
gitlab/gitlab-runner-helper x86_64-08a9e6f dd563202b49b 5 months ago 38.5MB
gitlab/gitlab-runner-helper x86_64-a67a225 510a68dddfac 5 months ago 38.8MB
gitlab/gitlab-runner-helper x86_64-33af656 481eb92e5b03 6 months ago 38.8MB
gitlab/gitlab-runner-helper x86_64-b32125f c846a6aa6e74 6 months ago 38.8MB
gitlab-runner-prebuilt-x86_64 a2efdd4 3f3ba3194117 8 months ago 38MB
gitlab-runner-prebuilt-x86_64 734bc5d 31a2021fe65c 9 months ago 38MB
gitlab-runner-prebuilt-x86_64 f896af7 ab67b27f989e 10 months ago 36.8MB
gitlab-runner-prebuilt-x86_64 c66b00d 02ef8ddfa31d 10 months ago 36.8MB
gitlab-runner-prebuilt-x86_64 c52ad4f c9ff2cbe78ca 10 months ago 39.4MB
gitlab-runner-prebuilt-x86_64 01b3ea1 9558eb1e0ec3 11 months ago 39.4MB
gitlab-runner-prebuilt-x86_64 fb49c47 bb0d1cfc227c 11 months ago 39.4MB
gitlab-runner-prebuilt-x86_64 76fdacd b5003037ec79 11 months ago 50.9MB
gitlab-runner-prebuilt-x86_64 bcc1794 5d14d1fe3893 12 months ago 50.2MB
gitlab-runner-prebuilt-x86_64 fae8f18 19dfd0c19fa1 13 months ago 50.2MB
gitlab-runner-prebuilt-x86_64 6220bd5 1163818b4f5c 13 months ago 50.2MB
What are they?
Can they be deleted?
Why aren't they cleaned up automatically?
Edited by Jörn Hees