Adding git-cache-proxy housekeeping service
requested to merge xen-project/people/anthonyper/xen-gitlab-ci:fix-git-cache-proxy-housekeeping into master
The housekeeping that git-cache-proxy is supposed to be doing while handling connections doesn't work when using systemd.socket.
The housekeeping task fork from the main process which is handling one connection, but the main process doesn't wait. So once the repo is served, systemd simply kill all remaining task. The housekeeping task never managed to finished. Often, it will even leave a "tmp_pack_*" file that can be big, and fill the disk slowly.
Add a service that is run daily to do the housekeeping task.
Reduce "gc-interval-days" to half the default, to try having this new .timer do the jobs rather than the .socket one. We can't disable the housekeeping done automatically at the moment.