This example registers upstream.connect/v2. It takes over the untouched client
stream, reads the handshake and login start packets, then returns a login
disconnect response unless fixture_accept is enabled. When the configured host
does not match, it calls Next with a replay wrapper so downstream handlers and
core still receive every byte.
The example is intentionally small: gateway core does not parse authentication results, identity mapping, forwarding, or play packets. Those responsibilities belong inside a connection takeover plugin.
The fixture emits auth.success / auth.failure events and an auth.attempts
counter with low-cardinality result and mode labels.
Build and package:
(cd ../../.. && go run ./cmd/gateway plugin test examples/plugins/mc-auth-proxy --profile manifest)
(cd ../../.. && go run ./cmd/gateway plugin build examples/plugins/mc-auth-proxy --type both)The binary package is written to dist/mc-auth-proxy.mcgp; the source package
is written to dist/mc-auth-proxy-source.mcgp.
The source manifest is maintained as manifest.yaml; packaged .mcgp artifacts
still contain canonical manifest.json.
Build the source package through the gateway builder:
(cd ../../.. && go run ./cmd/gateway plugin build --from-source examples/plugins/mc-auth-proxy/dist/mc-auth-proxy-source.mcgp --out examples/plugins/mc-auth-proxy/dist/mc-auth-proxy-built.mcgp)Example config JSON:
{
"match_host": "play.example",
"fixture_accept": false,
"disconnect_message": "Authentication fixture rejected the login"
}