scram support fails

[bubunyo]

No description provided.

[Copilot]

Pull request overview

This PR extends kroxy’s SASL pass-through model to support SCRAM-SHA-256 and SCRAM-SHA-512 in addition to PLAIN, enabling tenant routing based on the SCRAM client-first username while relaying SaslAuthenticate payloads to the upstream broker.

Changes:

• Refactors upstream connection setup to separate ApiVersions / SaslHandshake negotiation from mechanism-specific authentication, adding a SCRAM relay path.
• Adds proxy-side SCRAM handling: mechanism negotiation, username extraction from client-first-message for tenant routing, and SaslAuthenticate relay to upstream.
• Updates docs, metrics, and tests (unit + integration) to cover SCRAM mechanisms.

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
upstream/conn.go	Splits dialing/negotiation vs auth; adds DialForSCRAM + SaslAuthenticate relay helper.
proxy/conn.go	Adds SCRAM state handling and SaslAuthenticate relay flow; introduces SASL handshake/auth outcome metric.
auth/sasl_scram.go	Adds SCRAM mechanism constants and parsing of SCRAM client-first-message username.
observability/metrics.go	Adds a new Prometheus counter for SASL handshake/auth outcomes.
README.md	Documents SCRAM support and updated authentication model/limitations.
proxy/upstream_test.go	Extends fake broker to support multi-round SCRAM-style SaslAuthenticate replies.
proxy/conn_scram_test.go	Adds unit tests for SCRAM handshake advertisement and relay behavior.
integration/scram_test.go	Adds end-to-end SCRAM-SHA-256 / SCRAM-SHA-512 integration coverage.
integration/kafka_test.go	Updates Kafka container startup to enable SCRAM and provision SCRAM credentials.
dockerfiles/kafka_jaas.conf	Adds SCRAM login module to demo JAAS config.
dockerfiles/docker-compose.yml	Advertises SCRAM mechanisms and documents how to bootstrap SCRAM users in the demo stack.

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[Copilot]

Pull request overview

Copilot reviewed 16 out of 16 changed files in this pull request and generated 3 comments.