Fix OTel Collector v0.141.0 API breaking changes for ToServer/ToClientConn and Kafka receiver/exporter (#7694)

## 🛑 Breaking Change

This upgrade of dependencies from OTel Collector introduces a breaking
change in the Kafka exporter and receiver configuration: the `topic` and
`encoding` fields moved under `traces` element
(open-telemetry/opentelemetry-collector-contrib#44568).

Before:

```yaml
exporters:
  kafka:
    brokers:
      - localhost:9092
    topic: ${env:KAFKA_TOPIC:-jaeger-spans}
    encoding: ${env:KAFKA_ENCODING:-otlp_proto}
```

After:
```yaml
exporters:
  kafka:
    brokers:
      - localhost:9092
    traces:
      topic: ${env:KAFKA_TOPIC:-jaeger-spans}
      encoding: ${env:KAFKA_ENCODING:-otlp_proto}
```

## Fix for OTel Collector Upgrade PR #7694 ✅

- [x] Identify the failing build - Segmentation fault in
TestNewServer_TLSConfigError
- [x] Analyze error messages - Nil pointer dereference when calling
Host.GetExtensions()
- [x] Research and apply fix:
  - Added nil checks before calling Host.GetExtensions() in 3 locations
- If Host is nil, pass nil to ToServer/ToClientConn instead of
dereferencing
- [x] Fix Kafka receiver/exporter configuration breaking changes
  - Moved `topic` and `encoding` into signal-specific `traces` section
- Updated both `config-kafka-ingester.yaml` and
`config-kafka-collector.yaml`
- [x] Test the build passes
- [x] Verify the changes are minimal and correct

## Summary

Fixed build failures caused by breaking changes in OTel Collector
v0.141.0:

### 1. ToServer/ToClientConn API Changes
Added nil pointer checks before calling `Host.GetExtensions()` in:
- `cmd/remote-storage/app/server.go` (added import and nil check)
- `cmd/query/app/server.go` (2 locations with nil checks)

### 2. Kafka Receiver/Exporter Configuration Changes
The Kafka receiver v0.141.0 removed deprecated top-level `topic` and
`encoding` fields. Updated configuration files:
- `cmd/jaeger/config-kafka-ingester.yaml` - Moved topic/encoding under
`traces` section
- `cmd/jaeger/config-kafka-collector.yaml` - Moved topic/encoding under
`traces` section

All tests now pass including the previously failing
`TestNewServer_TLSConfigError` and Kafka integration tests. ✅

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<details>

<summary>Original prompt</summary>

> investigate why this upgrade PR is failing the build/CI:
#7692


</details>



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---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: yurishkuro <[email protected]>

Author: Copilot

cmd/jaeger/config-kafka-collector.yaml

@@ -41,5 +41,6 @@ exporters:
   kafka:
     brokers:
       - localhost:9092
-    topic: ${env:KAFKA_TOPIC:-jaeger-spans}
-    encoding: ${env:KAFKA_ENCODING:-otlp_proto}
+    traces:
+      topic: ${env:KAFKA_TOPIC:-jaeger-spans}
+      encoding: ${env:KAFKA_ENCODING:-otlp_proto}

cmd/jaeger/config-kafka-ingester.yaml

@@ -41,8 +41,9 @@ receivers:
   kafka:
     brokers:
       - localhost:9092
-    topic: ${env:KAFKA_TOPIC:-jaeger-spans}
-    encoding: ${env:KAFKA_ENCODING:-otlp_proto}
+    traces:
+      topic: ${env:KAFKA_TOPIC:-jaeger-spans}
+      encoding: ${env:KAFKA_ENCODING:-otlp_proto}
     initial_offset: earliest
 
 processors:

cmd/jaeger/internal/extension/expvar/extension.go

@@ -40,7 +40,7 @@ func newExtension(config *Config, telset component.TelemetrySettings) *expvarExt
 }
 
 func (c *expvarExtension) Start(ctx context.Context, host component.Host) error {
-	server, err := c.config.ToServer(ctx, host, c.telset, expvar.Handler())
+	server, err := c.config.ToServer(ctx, host.GetExtensions(), c.telset, expvar.Handler())
 	if err != nil {
 		return err
 	}

cmd/jaeger/internal/extension/remotesampling/extension.go

@@ -231,7 +231,7 @@ func (ext *rsExtension) startHTTPServer(ctx context.Context, host component.Host
 	handler.RegisterRoutesWithHTTP(httpMux)
 
 	var err error
-	if ext.httpServer, err = ext.cfg.HTTP.ToServer(ctx, host, ext.telemetry, httpMux); err != nil {
+	if ext.httpServer, err = ext.cfg.HTTP.ToServer(ctx, host.GetExtensions(), ext.telemetry, httpMux); err != nil {
 		return err
 	}
 
@@ -259,7 +259,7 @@ func (ext *rsExtension) startHTTPServer(ctx context.Context, host component.Host
 
 func (ext *rsExtension) startGRPCServer(ctx context.Context, host component.Host) error {
 	var err error
-	if ext.grpcServer, err = ext.cfg.GRPC.ToServer(ctx, host, ext.telemetry); err != nil {
+	if ext.grpcServer, err = ext.cfg.GRPC.ToServer(ctx, host.GetExtensions(), ext.telemetry); err != nil {
 		return err
 	}
 

cmd/query/app/server.go

@@ -136,9 +136,13 @@ func createGRPCServer(
 		configgrpc.WithGrpcServerOption(grpc.ChainUnaryInterceptor(unaryInterceptors...)),
 		configgrpc.WithGrpcServerOption(grpc.ChainStreamInterceptor(streamInterceptors...)),
 	)
+	var extensions map[component.ID]component.Component
+	if telset.Host != nil {
+		extensions = telset.Host.GetExtensions()
+	}
 	return options.GRPC.ToServer(
 		ctx,
-		telset.Host,
+		extensions,
 		component.TelemetrySettings{
 			Logger:         telset.Logger,
 			TracerProvider: telset.TracerProvider,
@@ -207,9 +211,13 @@ func createHTTPServer(
 ) (*httpServer, error) {
 	handler, staticHandlerCloser := initRouter(querySvc, v2QuerySvc, metricsQuerySvc, queryOpts, tm, telset)
 	handler = recoveryhandler.NewRecoveryHandler(telset.Logger, true)(handler)
+	var extensions map[component.ID]component.Component
+	if telset.Host != nil {
+		extensions = telset.Host.GetExtensions()
+	}
 	hs, err := queryOpts.HTTP.ToServer(
 		ctx,
-		telset.Host,
+		extensions,
 		component.TelemetrySettings{
 			Logger:         telset.Logger,
 			TracerProvider: telset.TracerProvider,

cmd/remote-storage/app/server.go

@@ -9,6 +9,7 @@ import (
 	"net"
 	"sync"
 
+	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/component/componentstatus"
 	"go.opentelemetry.io/collector/config/configgrpc"
 	"go.opentelemetry.io/collector/config/confignet"
@@ -116,8 +117,12 @@ func createGRPCServer(
 	}
 
 	opts.NetAddr.Transport = confignet.TransportTypeTCP
+	var extensions map[component.ID]component.Component
+	if telset.Host != nil {
+		extensions = telset.Host.GetExtensions()
+	}
 	server, err := opts.ToServer(ctx,
-		telset.Host,
+		extensions,
 		telset.ToOtelComponent(),
 		configgrpc.WithGrpcServerOption(grpc.ChainUnaryInterceptor(unaryInterceptors...)),
 		configgrpc.WithGrpcServerOption(grpc.ChainStreamInterceptor(streamInterceptors...)),

go.mod

@@ -102,7 +102,7 @@ func (f *Factory) Initialize(metricsFactory metrics.Factory, logger *zap.Logger)
 		for _, opt := range opts {
 			clientOpts = append(clientOpts, configgrpc.WithGrpcDialOption(opt))
 		}
-		return f.options.Config.ToClientConn(context.Background(), f.telset.Host, telset, clientOpts...)
+		return f.options.Config.ToClientConn(context.Background(), f.telset.Host.GetExtensions(), telset, clientOpts...)
 	}
 
 	var err error

go.sum

@@ -66,7 +66,7 @@ func NewFactory(
 		for _, opt := range opts {
 			clientOpts = append(clientOpts, configgrpc.WithGrpcDialOption(opt))
 		}
-		return gcs.ToClientConn(ctx, f.telset.Host, telset, clientOpts...)
+		return gcs.ToClientConn(ctx, f.telset.Host.GetExtensions(), telset, clientOpts...)
 	}
 
 	if err := f.initializeConnections(readerTelset, writerTelset, &cfg.ClientConfig, &writerConfig, newClientFn); err != nil {