The forward_auth target /outpost.goauthentik.io/auth/caddy does not exist
in authentik 2026.8 (verified live: 404 for every header combination; the
URL tree has no outpost auth prefix at all — the outpost worker dials back
to core over ws/outpost/<uuid>/ instead). Unauthenticated subrequests got
404, Caddy treated >=400 as 'not authenticated' and redirected browsers to
the dead path — users saw authentik's own Not-Found page.
Fix: guarded vhosts now proxy the whole request through authentik-server:9000
with X-authentik-meta-outpost/-provider/-app headers (the exact header set
this build's Traefik controller emits, adapted for Caddy). Unauthenticated
clients get the login flow served in place; once a session exists,
authentik proxies on to the provider's internal_host — now
http://caddy:8017, a new post-auth internal listener that routes straight to
the app. The chain terminates; nothing dials back into authentik.
Live DB changes applied alongside (postgres is the source of truth):
provider pk=1 authentication_flow=default-authentication-flow (was NULL —
the actual cause of the 404s) and internal_host=http://caddy:8017 (was
self-referential http://authentik-server:9000).
Frank
ef07e7d01a