## Problem
ref https://github.com/neondatabase/neon/pull/4721, ref
https://github.com/neondatabase/neon/issues/4709
## Summary of changes
This PR adds unit tests for wake_compute.
The patch adds a new variant `Test` to auth backends. When
`wake_compute` is called, we will verify if it is the exact operation
sequence we are expecting. The operation sequence now contains 3 more
operations: `Wake`, `WakeRetry`, and `WakeFail`.
The unit tests for proxy connects are now complete and I'll continue
work on WebSocket e2e test in future PRs.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
Checking out proxy logs for the endpoint is a frequent (often first) operation
during user issues investigation; let's remove endpoint id -> session id mapping
annoying extra step here.
For some reason, `tracing::instrument` proc_macro doesn't always print
elements specified via `fields()` or even show that it's impossible
(e.g. there's no Display impl).
Work around this using the `?foo` notation.
Before:
2023-04-03T14:48:06.017504Z INFO handle_client🤝 received SslRequest
After:
2023-04-03T14:51:24.424176Z INFO handle_client{session_id=7bd07be8-3462-404e-8ccc-0a5332bf3ace}🤝 received SslRequest
It's not a property of the credentials that we receive from the
client, so remove it from ClientCredentials. Instead, pass it as an
argument directly to 'authenticate' function, where it's actually
used. All the rest of the changes is just plumbing to pass it through
the call stack to 'authenticate'
The project/endpoint should be set in the original (non-as_ref'd) creds,
because we call `wake_compute` not only in `try_password_hack` but also
later in the connection retry logic.
This PR also removes the obsolete `as_ref` method and makes the code
simpler because we no longer need this complication after a recent
refactoring.
Further action points: finally introduce typestate in creds (planned).
This patch adds a timed LRU cache implementation and a compute node info cache on top of that.
Cache entries might expire on their own (default ttl=5mins) or become invalid due to real-world events,
e.g. compute node scale-to-zero event, so we add a connection retry loop with a wake-up call.
Solved problems:
- [x] Find a decent LRU implementation.
- [x] Implement timed LRU on top of that.
- [x] Cache results of `proxy_wake_compute` API call.
- [x] Don't invalidate newer cache entries for the same key.
- [x] Add cmdline configuration knobs (requires some refactoring).
- [x] Add failed connection estab metric.
- [x] Refactor auth backends to make things simpler (retries, cache
placement, etc).
- [x] Address review comments (add code comments + cleanup).
- [x] Retry `/proxy_wake_compute` if we couldn't connect to a compute
(e.g. stalled cache entry).
- [x] Add high-level description for `TimedLru`.
TODOs (will be addressed later):
- [ ] Add cache metrics (hit, spurious hit, miss).
- [ ] Synchronize http requests across concurrent per-client tasks
(https://github.com/neondatabase/neon/pull/3331#issuecomment-1399216069).
- [ ] Cache results of `proxy_get_role_secret` API call.
This is a hacky implementation of WebSocket server, embedded into our
postgres proxy. The server is used to allow https://github.com/neondatabase/serverless
to connect to our postgres from browser and serverless javascript functions.
How it will work (general schema):
- browser opens a websocket connection to
`wss://ep-abc-xyz-123.xx-central-1.aws.neon.tech/`
- proxy accepts this connection and terminates TLS (https)
- inside encrypted tunnel (HTTPS), browser initiates plain
(non-encrypted) postgres connection
- proxy performs auth as in usual plain pg connection and forwards
connection to the compute
Related issue: #3225
Previously, proxy didn't forward auxiliary `options` parameter
and other ones to the client's compute node, e.g.
```
$ psql "user=john host=localhost dbname=postgres options='-cgeqo=off'"
postgres=# show geqo;
┌──────┐
│ geqo │
├──────┤
│ on │
└──────┘
(1 row)
```
With this patch we now forward `options`, `application_name` and `replication`.
Further reading: https://www.postgresql.org/docs/current/libpq-connect.htmlFixes#1287.
The new format has a few benefits: it's shorter, simpler and
human-readable as well. We don't use base64 anymore, since
url encoding got us covered.
We also show a better error in case we couldn't parse the
payload; the users should know it's all about passing the
correct project name.
[proxy] Add the `password hack` authentication flow
This lets us authenticate users which can use neither
SNI (due to old libpq) nor connection string `options`
(due to restrictions in other client libraries).
Note: `PasswordHack` will accept passwords which are not
encoded in base64 via the "password" field. The assumption
is that most user passwords will be valid utf-8 strings,
and the rest may still be passed via "password_".
