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.
[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_".
* Added project option in case SNI data is missing. Resolving issue #1745.
* Added invariant checking for project name: if both sni_data and project_name are available then they should match.
Now proxy binary accepts `--auth-backend` CLI option, which determines
auth scheme and cluster routing method. Following backends are currently
implemented:
* legacy
old method, when username ends with `@zenith` it uses md5 auth dbname as
the cluster name; otherwise, it sends a login link and waits for the console
to call back
* console
new SCRAM-based console API; uses SNI info to select the destination
cluster
* postgres
uses postgres to select auth secrets of existing roles. Useful for local
testing
* link
sends login link for all usernames
* `cloud::legacy` talks to Cloud API V1.
* `cloud::api` defines Cloud API v2.
* `cloud::local` mocks the Cloud API V2 using a local postgres instance.
* It's possible to choose between API versions using the `--api-version` flag.
When failpoint feature is disabled it throws away passed code so code
inside is not guaranteed to compile when feature is disabled. In this
particular case code is obsolete so removing it.
* [proxy] Add SCRAM auth
* [proxy] Implement some tests for SCRAM
* Refactoring + test fixes
* Hide SCRAM mechanism behind `#[cfg(test)]`
Currently we only use it in tests, so we hide all relevant
module behind `#[cfg(test)]` to prevent "unused item" warnings.
