otlp receiver: Fix HTTP server config source and legacy port mutation (…

…#4631)

CHANGELOG.md

@@ -32,6 +32,7 @@
 
 - Fix merge config map provider to close the watchers (#4570)
 - Fix expand map provider to call close on the base provider (#4571)
+- `otlp` receiver: Fix legacy port cfg value override and HTTP server starting bug (#4631)
 
 ## v0.41.0 Beta
 

receiver/otlpreceiver/otlp.go

@@ -86,7 +86,7 @@ func (r *otlpReceiver) startGRPCServer(cfg *configgrpc.GRPCServerSettings, host
 func (r *otlpReceiver) startHTTPServer(cfg *confighttp.HTTPServerSettings, host component.Host) error {
 	r.settings.Logger.Info("Starting HTTP server on endpoint " + cfg.Endpoint)
 	var hln net.Listener
-	hln, err := r.cfg.HTTP.ToListener()
+	hln, err := cfg.ToListener()
 	if err != nil {
 		return err
 	}
@@ -147,10 +147,10 @@ func (r *otlpReceiver) startProtocolServers(host component.Host) error {
 			r.settings.Logger.Info("Setting up a second HTTP listener on legacy endpoint " + legacyHTTPEndpoint)
 
 			// Copy the config.
-			cfgLegacyHTTP := r.cfg.HTTP
+			cfgLegacyHTTP := *(r.cfg.HTTP)
 			// And use the legacy endpoint.
 			cfgLegacyHTTP.Endpoint = legacyHTTPEndpoint
-			err = r.startHTTPServer(cfgLegacyHTTP, host)
+			err = r.startHTTPServer(&cfgLegacyHTTP, host)
 			if err != nil {
 				return err
 			}

receiver/otlpreceiver/otlp_test.go

@@ -24,11 +24,14 @@ import (
 	"io/ioutil"
 	"net"
 	"net/http"
+	"strings"
 	"testing"
 	"time"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"go.uber.org/zap"
+	"go.uber.org/zap/zaptest/observer"
 	spb "google.golang.org/genproto/googleapis/rpc/status"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
@@ -46,6 +49,7 @@ import (
 	"go.opentelemetry.io/collector/consumer"
 	"go.opentelemetry.io/collector/consumer/consumertest"
 	"go.opentelemetry.io/collector/internal/internalconsumertest"
+	"go.opentelemetry.io/collector/internal/sharedcomponent"
 	"go.opentelemetry.io/collector/internal/testdata"
 	"go.opentelemetry.io/collector/internal/testutil"
 	"go.opentelemetry.io/collector/model/otlp"
@@ -629,6 +633,41 @@ func TestHTTPInvalidTLSCredentials(t *testing.T) {
 		`failed to load TLS config: for auth via TLS, either both certificate and key must be supplied, or neither`)
 }
 
+func TestHTTPUseLegacyPortWhenUsingDefaultEndpoint(t *testing.T) {
+	r := newHTTPReceiver(t, defaultHTTPEndpoint, consumertest.NewNop(), consumertest.NewNop())
+	require.NotNil(t, r)
+
+	logCore, logs := observer.New(zap.InfoLevel)
+	logger := zap.New(logCore)
+
+	metric := r.(*sharedcomponent.SharedComponent).Unwrap().(*otlpReceiver)
+	metric.settings.Logger = logger
+
+	t.Cleanup(func() { require.NoError(t, r.Shutdown(context.Background())) })
+
+	require.NoError(t, r.Start(context.Background(), componenttest.NewNopHost()))
+
+	require.True(t, func() bool {
+		for _, l := range logs.All() {
+			if strings.Contains(l.Message, "Setting up a second HTTP listener on legacy endpoint 0.0.0.0:55681") {
+				return true
+			}
+		}
+		return false
+	}())
+
+	require.False(t, func() bool {
+		for _, l := range logs.All() {
+			if strings.Contains(l.Message, "Legacy HTTP endpoint 0.0.0.0:55681 is configured, please use 0.0.0.0:4318 instead.") {
+				return true
+			}
+		}
+		return false
+	}())
+
+	require.Equal(t, defaultHTTPEndpoint, metric.cfg.HTTP.Endpoint)
+}
+
 func newGRPCReceiver(t *testing.T, name string, endpoint string, tc consumer.Traces, mc consumer.Metrics) component.Component {
 	factory := NewFactory()
 	cfg := factory.CreateDefaultConfig().(*Config)