Synapse on Postgres plus the Element web client, on two subdomains: the
homeserver on matrix.<domain> (which becomes server_name, so IDs read
@alice:matrix.<domain>) and Element on element.<domain>.
Two hosts rather than one because server_name then matches the host Traefik
already terminates TLS for, so 'serve_server_wellknown: true' is all the
federation delegation needed and nothing has to be published at the apex
domain — which this app has no way to configure.
CFG_MATRIX_AUTHELIA is pinned false and documented: forward-auth in front of
/_matrix locks out every client and every federating peer, since they carry
Matrix access tokens and cannot follow a redirect. Real SSO goes through the
OIDC block in resources/homeserver.yaml instead.
The install hook generates the signing key once via upstream's own 'generate'
command and refuses to regenerate it over an existing install — a new key would
be rejected by every server that had cached the old one.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
