Patroni's REST API accepted changes from anyone on port 8008, and
PostgreSQL ran with sslmode=disable between machines. Setup now keeps a
fourth secret for the API (carried to members of older clusters), issues
each member a certificate from the cluster's authority, writes
restapi.authentication into each member's config and reloads it, and
turns ssl on with hostssl remote rules through an authenticated PATCH of
the shared configuration. The DSN becomes sslmode=verify-full against the
authority's certificate whenever the cluster has TLS, so a control plane
without the authority's key reconnects too. server add authenticates its
PATCH and lets the new control plane in by hostssl. Tried on the e2e
cluster: unauthenticated PATCH 401, plaintext refused, replication
streaming, the control plane on verify-full.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
