## Problem
It seems are production-ready cert-manager setup now includes a full
certificate chain. This was not accounted for and the decoder would
error.
## Summary of changes
Change the way we decode certificates to support cert-chains, ignoring
all but the first cert.
This also changes a log line to not use multi-line errors.
~~I have tested this code manually against real certificates/keys, I
didn't want to embed those in a test just yet, not until the cert
expires in 24 hours.~~
Both crates seem well maintained. x509-cert is part of the high quality
RustCrypto project that we already make heavy use of, and I think it
makes sense to reduce the dependencies where possible.
Closes: https://github.com/neondatabase/cloud/issues/22998
If control-plane reports that TLS should be used, load the certificates
(and watch for updates), make sure postgres use them, and detects
updates.
Procedure:
1. Load certificates
2. Reconfigure postgres/pgbouncer
3. Loop on a timer until certificates have loaded
4. Go to 1
Notes:
1. We only run this procedure if requested on startup by control plane.
2. We needed to compile pgbouncer with openssl enabled
3. Postgres doesn't allow tls keys to be globally accessible - must be
read only to the postgres user. I couldn't convince the autoscaling team
to let me put this logic into the VM settings, so instead compute_ctl
will copy the keys to be read-only by postgres.
4. To mitigate a race condition, we also verify that the key matches the
cert.
