Synapse mounts its admin API on the same vhost as the client API, so publishing matrix.phasefinal.com published the admin surface too -- it answered 200 from the open internet. HMAC-protected, so not an open door, but Synapse's own guidance is to keep it off the public listener. A higher-priority router (explicit priority 100, not relying on Traefik's rule-length tie-break) scopes PathPrefix(/_synapse/admin) behind an ipallowlist. Verified from a genuinely external vantage rather than from a fleet host, since nh3-dev sits inside the allowed range and would have proved nothing: via the NH3 residential egress proxy the admin path returns 403 while the client API returns 200 and Element is unaffected. The 10.0.0.0/8 entry matches nothing today and the comment says so rather than implying fleet access exists. matrix.phasefinal.com resolves publicly, so fleet hosts hairpin out their own WAN -- a request from nh3-dev arrived as 70.230.226.88. The rule is effectively deny-all through Traefik, which is the intended posture: admin work goes through docker exec to localhost:8008 and never traverses Traefik. Allow-listing the sites' WAN addresses was considered and rejected as a maintenance trap on dynamic addresses. Also brings the stack under stacks/ with the Postgres password replaced by a required .env variable. The tracked copy and the live file have therefore DIVERGED and deploy-stack.sh must not be used until the live file reads from a .env; the README says so.
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synapse — Matrix homeserver (ana-docker)
Canonical copy of the stack running at /opt/docker/compose/synapse/ on
ana-docker (10.250.50.70). Serves matrix.phasefinal.com and
chat.phasefinal.com through Traefik.
Deep documentation — current versions, the upgrade procedure, the appservice
namespace decision, conventions, and the push-notification findings — lives in
docs/pfi/vm-102-matrix-synapse.md.
This file covers only what is specific to deploying the stack.
⚠ The password is NOT in this copy
The live compose carries POSTGRES_PASSWORD inline in plaintext. This
tracked copy replaces it with ${POSTGRES_PASSWORD:?set in .env} so the secret
is not committed.
They have therefore diverged, and deploy-stack.sh would push the
placeholder over a working literal and break the database on next recreate.
Do not deploy this stack from the repo until the live file has been converted
to read from a .env — which is the right fix and is not done yet.
Until then: edit the live file on the host, then re-mirror to here.
/_synapse/admin is LAN-only
Synapse mounts its admin API on the same vhost as the client API, so publishing
matrix.phasefinal.com published the admin surface with it — it answered 200
from the open internet until 2026-09-01.
A higher-priority router now scopes PathPrefix(/_synapse/admin) behind an
ipallowlist. Verified from a genuinely external vantage (the NH3 residential
egress proxy, not a fleet host): admin 403, client API 200, Element
unaffected.
⚠ The 10.0.0.0/8 entry currently matches nothing, deliberately. The hostname
resolves publicly, so fleet hosts hairpin out their own WAN and arrive as a
public address — a request from nh3-dev measured as 70.230.226.88. The rule is
effectively deny-all through Traefik, which is intended: admin work is done
with docker exec synapse against localhost:8008, which never touches
Traefik. Allow-listing the sites' WAN addresses was rejected — they are dynamic,
and a stale entry either locks us out or hands admin to whoever inherits the
address.
Upgrades
Take a verified pg_dump first. Schema migrations are one-way; an older
Synapse will not start against a newer database, so rollback is restore, not
revert. Full procedure in the docs link above.