Asterisk and Mattermost each used to embed their own dedicated coturn
container (network_mode: host), and their default relay port ranges
overlapped by ~100 UDP ports — running both on one box meant a
coin-flip over which service's active call lost its media relay.
- services/coturn.sh: new shared TURN/STUN relay, one instance for
every consumer instead of one each. Runs --lt-cred-mech with a
SQLite user database (not --use-auth-secret — coturn doesn't
support both auth mechanisms on one instance at once, confirmed via
coturn's own upstream docs/issues) so each consumer gets its own
dedicated username/password without stepping on any other's.
- lib/common.sh: ensure_coturn_user() — chain-installs coturn.sh on
first need (same declare -F guard pattern as the existing
asterisk -> security-dashboard chaining) and registers/reuses a
per-consumer credential, mirroring configure_caddy_for_service's
out-param convention.
- services/asterisk.sh: _asterisk_write_compose gains a
USE_EMBEDDED_COTURN flag. New installs use the shared service;
existing installs keep their dedicated coturn exactly as-is on
every "update" (detected from the existing compose file before
regenerating it, so a rebuild can never silently drop the container
its own .env TURN_PASSWORD still points at) and only switch on an
explicit "fresh" reinstall, with a warning first.
- services/mattermost.sh: same embedded/shared coturn handling, plus
genuine multi-instance support (separate dir/containers/DB/ports per
instance, auto-scanned free ports for extras) for real isolation
between groups, as opposed to Team Edition's built-in Teams feature.
Calls plugin TURN config switched from the HMAC "TURN Static Auth
Secret" field to the verified "ICE Servers Configurations" JSON
field, which accepts the same fixed username/credential shared
coturn issues. Also fixes a latent bug found while adding proper
update-mode detection: DB_PASS/MM_SECRET were regenerated on every
single rerun with no existing-install check at all, silently
breaking Postgres auth on any reinstall.
- CLAUDE.md: documents the ensure_coturn_user pattern (including the
auth-mechanism constraint and the embedded-coturn migration-safety
rule) for any future service that needs TURN.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NQkdAn3iG5A4WoqU9FHMaN
