Translate broker addresses in DescribeCluster response - Closes #17 (#18)

Signed-off-by: Jakub Scholz <www@scholzj.com>

Author: scholzj

go.mod

@@ -3,7 +3,7 @@ module github.com/scholzj/kekspose
 go 1.24.0
 
 require (
-	github.com/scholzj/go-kafka-protocol v0.0.1
+	github.com/scholzj/go-kafka-protocol v0.0.2
 	github.com/scholzj/strimzi-go v0.6.0
 	github.com/spf13/cobra v1.10.2
 	github.com/stretchr/testify v1.11.1

go.sum

@@ -91,8 +91,8 @@ github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2/go.mod h1:iKH
 github.com/rogpeppe/go-internal v1.13.1 h1:KvO1DLK/DRN07sQ1LQKScxyZJuNnedQ5/wKSR38lUII=
 github.com/rogpeppe/go-internal v1.13.1/go.mod h1:uMEvuHeurkdAXX61udpOXGD/AzZDWNMNyH2VO9fmH0o=
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
-github.com/scholzj/go-kafka-protocol v0.0.1 h1:DXaVfboTBMHsYjgA3XPtOiR6bO4TvmhMVNDhUCOdmQc=
-github.com/scholzj/go-kafka-protocol v0.0.1/go.mod h1:5A/liM02deqyur7XYmBFQu/ETZACtSLrETJDQlvDJL4=
+github.com/scholzj/go-kafka-protocol v0.0.2 h1:/s/pz4b5INovlLezrBn8qR0/AE03V/ijmnZvYpZQAZI=
+github.com/scholzj/go-kafka-protocol v0.0.2/go.mod h1:5A/liM02deqyur7XYmBFQu/ETZACtSLrETJDQlvDJL4=
 github.com/scholzj/strimzi-go v0.6.0 h1:DEvIy9/00q1r83eSSKZVGeDx/UMKcNPMsaWtAAzdfLk=
 github.com/scholzj/strimzi-go v0.6.0/go.mod h1:fO//Ti6/rrsC0dbQ09iNsy4Rf5yHcH4pt6VXioKJaQY=
 github.com/spf13/cobra v1.10.2 h1:DMTTonx5m65Ic0GOoRY2c16WCbHxOOw6xxezuLaBpcU=

pkg/kekspose/proksy/proksy.go

@@ -8,6 +8,7 @@ import (
 	"net"
 
 	"github.com/scholzj/go-kafka-protocol/api/apiversions"
+	"github.com/scholzj/go-kafka-protocol/api/describecluster"
 	"github.com/scholzj/go-kafka-protocol/api/findcoordinator"
 	"github.com/scholzj/go-kafka-protocol/api/metadata"
 	"github.com/scholzj/go-kafka-protocol/protocol"
@@ -66,7 +67,7 @@ func (p *Proksy) BrokerToClient(client net.Conn, broker httpstream.Stream, shutd
 			}
 
 			for i := range *metadataResponse.Brokers {
-				(*metadataResponse.Brokers)[i].Host = "localhost"
+				(*metadataResponse.Brokers)[i].Host = ptr.To("localhost")
 				(*metadataResponse.Brokers)[i].Port = int32(p.PortMapping[(*metadataResponse.Brokers)[i].NodeId])
 			}
 
@@ -119,6 +120,28 @@ func (p *Proksy) BrokerToClient(client net.Conn, broker httpstream.Stream, shutd
 				slog.Error("<- Failed to re-encode ApiVersions response", "node", p.NodeId, "error", err)
 			}
 			response.Body = buf
+		} else if response.ApiKey == 60 {
+			describeCluster := describecluster.DescribeClusterResponse{}
+			err := describeCluster.Read(response)
+			if err != nil {
+				slog.Error("<- Failed to decode DescribeCluster response", "node", p.NodeId, "error", err)
+			}
+
+			if describeCluster.EndpointType == 1 && describeCluster.Brokers != nil {
+				for i := range *describeCluster.Brokers {
+					(*describeCluster.Brokers)[i].Host = ptr.To("localhost")
+					(*describeCluster.Brokers)[i].Port = int32(p.PortMapping[(*describeCluster.Brokers)[i].BrokerId])
+				}
+			}
+
+			slog.Log(context.Background(), TraceLevel, describeCluster.PrettyPrint())
+
+			buf := bytes.NewBuffer(make([]byte, 0))
+			err = describeCluster.Write(buf)
+			if err != nil {
+				slog.Error("<- Failed to re-encode DescribeCluster response", "node", p.NodeId, "error", err)
+			}
+			response.Body = buf
 		}
 
 		slog.Debug("<- Proxying response from remote", "node", p.NodeId)