## Problem
For #11992 I realised we need to get the type info before executing the
query. This is important to know how to decode rows with custom types,
eg the following query:
```sql
CREATE TYPE foo AS ENUM ('foo','bar','baz');
SELECT ARRAY['foo'::foo, 'bar'::foo, 'baz'::foo] AS data;
```
Getting that to work was harder that it seems. The original
tokio-postgres setup has a split between `Client` and `Connection`,
where messages are passed between. Because multiple clients were
supported, each client message included a dedicated response channel.
Each request would be terminated by the `ReadyForQuery` message.
The flow I opted to use for parsing types early would not trigger a
`ReadyForQuery`. The flow is as follows:
```
PARSE "" // parse the user provided query
DESCRIBE "" // describe the query, returning param/result type oids
FLUSH // force postgres to flush the responses early
// wait for descriptions
// check if we know the types, if we don't then
// setup the typeinfo query and execute it against each OID:
PARSE typeinfo // prepare our typeinfo query
DESCRIBE typeinfo
FLUSH // force postgres to flush the responses early
// wait for typeinfo statement
// for each OID we don't know:
BIND typeinfo
EXECUTE
FLUSH
// wait for type info, might reveal more OIDs to inspect
// close the typeinfo query, we cache the OID->type map and this is kinder to pgbouncer.
CLOSE typeinfo
// finally once we know all the OIDs:
BIND "" // bind the user provided query - already parsed - to the user provided params
EXECUTE // run the user provided query
SYNC // commit the transaction
```
## Summary of changes
Please review commit by commit. The main challenge was allowing one
query to issue multiple sub-queries. To do this I first made sure that
the client could fully own the connection, which required removing any
shared client state. I then had to replace the way responses are sent to
the client, by using only a single permanent channel. This required some
additional effort to track which query is being processed. Lastly I had
to modify the query/typeinfo functions to not issue `sync` commands, so
it would fit into the desired flow above.
To note: the flow above does force an extra roundtrip into each query. I
don't know yet if this has a measurable latency overhead.
https://github.com/neondatabase/cloud/issues/23008
For TLS between proxy and compute, we are using an internally
provisioned CA to sign the compute certificates. This change ensures
that proxy will load them from a supplied env var pointing to the
correct file - this file and env var will be configured later, using a
kubernetes secret.
Control plane responds with a `server_name` field if and only if the
compute uses TLS. This server name is the name we use to validate the
certificate. Control plane still sends us the IP to connect to as well
(to support overlay IP).
To support this change, I'd had to split `host` and `host_addr` into
separate fields. Using `host_addr` and bypassing `lookup_addr` if
possible (which is what happens in production). `host` then is only used
for the TLS connection.
There's no blocker to merging this. The code paths will not be triggered
until the new control plane is deployed and the `enableTLS` compute flag
is enabled on a project.
This upgrades the `proxy/` crate as well as the forked libraries in
`libs/proxy/` to edition 2024.
Also reformats the imports of those forked libraries via:
```
cargo +nightly fmt -p proxy -p postgres-protocol2 -p postgres-types2 -p tokio-postgres2 -- -l --config imports_granularity=Module,group_imports=StdExternalCrate,reorder_imports=true
```
It can be read commit-by-commit: the first commit has no formatting
changes, only changes to accomodate the new edition.
Part of #10918
(stacked on #9990 and #9995)
Partially fixes#1287 with a custom option field to enable the fixed
behaviour. This allows us to gradually roll out the fix without silently
changing the observed behaviour for our customers.
related to https://github.com/neondatabase/cloud/issues/15284
Fixes https://github.com/neondatabase/cloud/issues/20973.
This refactors `connect_raw` in order to return direct access to the
delayed notices.
I cannot find a way to test this with psycopg2 unfortunately, although
testing it with psql does return the expected results.
Our rust-postgres fork is getting messy. Mostly because proxy wants more
control over the raw protocol than tokio-postgres provides. As such,
it's diverging more and more. Storage and compute also make use of
rust-postgres, but in more normal usage, thus they don't need our crazy
changes.
Idea:
* proxy maintains their subset
* other teams use a minimal patch set against upstream rust-postgres
Reviewing this code will be difficult. To implement it, I
1. Copied tokio-postgres, postgres-protocol and postgres-types from
00940fcdb5
2. Updated their package names with the `2` suffix to make them compile
in the workspace.
3. Updated proxy to use those packages
4. Copied in the code from tokio-postgres-rustls 0.13 (with some patches
applied https://github.com/jbg/tokio-postgres-rustls/pull/32https://github.com/jbg/tokio-postgres-rustls/pull/33)
5. Removed as much dead code as I could find in the vendored libraries
6. Updated the tokio-postgres-rustls code to use our existing channel
binding implementation
