feat(proxy): allow proxy to connect to separate compute compared to mock cplane

[conradludgate]

@a-masterov was asking for a way to test compute via proxy. This change allows for an easy way to mock the cplane api in a standalone postgres, while testing against a separate neon compute.

The following guide will be added to the proxy/README.md after some workshopping:

---

To setup locally, run a postgres server with the following schema:

CREATE SCHEMA neon_control_plane;
CREATE TABLE neon_control_plane.endpoints (
    endpoint_id text PRIMARY KEY,
    allowed_ips text,
    host text not null,
    port integer not null
);

And insert a host/port for your endpoint accordingly.

Create a certificate pair for proxy

openssl req -new -x509 -days 365 -nodes -text -out proxy.crt -keyout proxy.key -subj '/CN=*.localtest.me'

Run proxy

cargo run --bin proxy \
    --auth-backend postgres \
    --auth-endpoint "$CPLANE_MOCK" \
    -c proxy.crt -k proxy.key \
    --proxy "127.0.0.1:5432" \
    --mgmt "127.0.0.1:8080"

And connect to proxy via

psql "postgresql://${username}:${password}@${ENDPOINT}.localtest.me/dbname?sslmode=require"

Caveat, the username and password must be exactly the same in both postgres databases for this to work - in fact the salts need to be the same too which likely less useful 🙃 but it is still possible to do using CREATE ROLE role WITH ENCRYPTED PASSWORD '...'

[github-actions]

7095 tests run: 6785 passed, 12 failed, 298 skipped (full report)

---

Failures on Postgres 17

• test_pageserver_small_inmemory_layers[False]: debug-x86-64
• test_proxy_http_allowed_ips: release-x86-64, release-x86-64, debug-x86-64, release-arm64, release-arm64

Failures on Postgres 16

• test_proxy_http_allowed_ips: release-x86-64, release-arm64

Failures on Postgres 15

• test_proxy_http_allowed_ips: release-x86-64, release-arm64

Failures on Postgres 14

• test_proxy_http_allowed_ips: release-x86-64, release-arm64

# Run all failed tests locally:
scripts/pytest -vv -n $(nproc) -k "test_proxy_http_allowed_ips[release-pg14] or test_proxy_http_allowed_ips[release-pg14] or test_proxy_http_allowed_ips[release-pg15] or test_proxy_http_allowed_ips[release-pg15] or test_proxy_http_allowed_ips[release-pg16] or test_proxy_http_allowed_ips[release-pg16] or test_pageserver_small_inmemory_layers[debug-pg17-False] or test_proxy_http_allowed_ips[release-pg17] or test_proxy_http_allowed_ips[release-pg17] or test_proxy_http_allowed_ips[debug-pg17] or test_proxy_http_allowed_ips[release-pg17] or test_proxy_http_allowed_ips[release-pg17]"

Flaky tests (2)

Postgres 17

• test_sharding_split_smoke: release-arm64

Postgres 15

• test_physical_replication_config_mismatch_too_many_known_xids: release-arm64

Test coverage report is not available

_{The comment gets automatically updated with the latest test results
a93639a at 2024-12-17T21:09:42.126Z :recycle:}