Security audit 2026-10-17, finding I6 (low), stage 3. /healthz is
registered outside auth and every proxy fragment passed it through: the
live server answered "ok" to the internet, and "unhealthy: postfix"
would have been a free tell.
Now handleHealth answers only a request with no X-Forwarded-For (nor
Forwarded) from loopback or a private address: the image's HEALTHCHECK
(127.0.0.1), the host through the loopback-published port (the Docker
gateway), a monitor on the Docker network. Every supported proxy appends
X-Forwarded-For, so through it the endpoint is 404. The plan named
"trusted-proxy peers"; that would have let the internet in again through
the trusted proxy, hence this shape. The e2e's readiness probe is the
host's, and stays answered.
Test: TestHealthzAnswersOnlyLocalProbes. Docs: guide § Container health,
architecture.md; CHANGELOG; plan.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
mixandClaude Opus 5.5
a327962008