# Docker disk hygiene for the self-hosted Gitea Actions runner (home-runner-1, 192.168.1.52).
#
# Why this exists: every CI push builds and sha-<commit>-tags a Docker image per pipeline
# (rust-ci, web, docs, fedora-rpm, fedora44-rpm, ...). Those tags are never dangling, so a
# plain `docker image prune` SKIPS them and they accumulate. Host-level, not per-repo CI,
# because the runner is shared (punktfunk + other orgs all benefit).
#
# THE BIG ONE (2026-06-19): the act_runner CACHE SERVER store lives in the long-running runner
# container's WRITABLE LAYER (HOME/.cache/actcache/cache inside gitea-runner-runner-1,
# `cache.dir: ""` -> defaults under /root). `docker prune` can NEVER see it — only stopped
# containers + unused images/cache are prunable, not a 13-day-up container's layer. That store
# grew to ~66 GB and filled a 125 GB disk on its own. docker-prune.sh caps it by clearing the
# blobs in-place (act_runner repopulates; keys are content-hashed).
#
# The logic is in docker-prune.sh, NOT inline ExecStart=, because systemd does its own
# $-expansion on ExecStart and would empty the shell vars / $(...) before sh runs them.
#
# Install on the runner host (root):
#   install -m755 scripts/ci/docker-prune.sh /usr/local/bin/ci-docker-prune.sh
#   cp scripts/ci/docker-prune.{service,timer} /etc/systemd/system/
#   systemctl daemon-reload && systemctl enable --now docker-prune.timer
# See also scripts/ci/setup-macos-runner.sh for the macOS runner.

[Unit]
Description=Prune aged Docker images/cache + cap the act_runner cache (CI runner disk hygiene)
Documentation=https://git.unom.io/unom/punktfunk
Wants=docker.service
After=docker.service

[Service]
Type=oneshot
ExecStart=/usr/local/bin/ci-docker-prune.sh