The official mattermost/mattermost-team-edition image runs as a fixed
UID/GID 2000 baked into the image — it does not read PUID/PGID env vars,
that's a LinuxServer.io s6-overlay convention this image doesn't use.
This file set them anyway (computed from ACTUAL_USER's uid/gid), which
did nothing, while the actual host directories (./data, ./logs,
./config, ./plugins) got chowned to ACTUAL_USER instead of 2000:2000.
Confirmed live: the container fails on its very first start with
"could not create config file: open /mattermost/config/config.json:
permission denied" and crash-loops — which then presents as a 502 from
Caddy, an easy trail to follow to the wrong place since Caddy itself
was fine.
Removed the dead PUID/PGID mechanism and chown the app's own volumes to
2000:2000 after the existing ACTUAL_USER chown. db (postgres:15-alpine)
isn't affected — its entrypoint fixes its own volume ownership on
startup. Runs on both fresh installs and "update" reruns, so re-running
the installer on an already-broken instance self-heals it.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01H4k6J1qXXyYxhGEgnJaMvn
Claude
39e7b2ae6e