Add default config for collector (#899)

nginx · Oct 17, 2024 · 0ea4a5f · 0ea4a5f
1 parent ea60800
commit 0ea4a5f
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Showing 15 changed files with 352 additions and 123 deletions.
diff --git a/internal/collector/otel_collector_plugin.go b/internal/collector/otel_collector_plugin.go
@@ -63,6 +63,7 @@ func New(conf *config.Config) (*Collector, error) {
 	return &Collector{
 		config:  conf,
 		service: oTelCollector,
+		stopped: true,
 	}, nil
 }
 
@@ -73,6 +74,13 @@ func (oc *Collector) Init(ctx context.Context, mp bus.MessagePipeInterface) erro
 	var runCtx context.Context
 	runCtx, oc.cancel = context.WithCancel(ctx)
 
+	if !oc.config.AreReceiversConfigured() {
+		slog.InfoContext(runCtx, "No receivers configured for OTel Collector. "+
+			"Waiting to discover a receiver before starting OTel collector.")
+
+		return nil
+	}
+
 	err := writeCollectorConfig(oc.config.Collector)
 	if err != nil {
 		return fmt.Errorf("write OTel Collector config: %w", err)

diff --git a/internal/collector/otel_collector_plugin_test.go b/internal/collector/otel_collector_plugin_test.go
@@ -5,11 +5,15 @@
 package collector
 
 import (
+	"bytes"
 	"context"
 	"fmt"
+	"strings"
 	"testing"
 	"time"
 
+	"github.com/nginx/agent/v3/test/stub"
+
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"go.opentelemetry.io/collector/otelcol"
@@ -29,6 +33,27 @@ func TestCollector_New(t *testing.T) {
 	require.NoError(t, err, "NewCollector should not return an error with valid config")
 }
 
+func TestCollector_Init(t *testing.T) {
+	conf := types.OTelConfig(t)
+	conf.Collector = &config.Collector{}
+
+	logBuf := &bytes.Buffer{}
+	stub.StubLoggerWith(logBuf)
+
+	collector, err := New(conf)
+	require.NoError(t, err, "NewCollector should not return an error with valid config")
+
+	initError := collector.Init(context.Background(), nil)
+	require.NoError(t, initError)
+
+	if s := logBuf.String(); !strings.Contains(s, "No receivers configured for OTel Collector. "+
+		"Waiting to discover a receiver before starting OTel collector.") {
+		t.Errorf("Unexpected log %s", s)
+	}
+
+	assert.True(t, collector.stopped)
+}
+
 func TestCollector_InitAndClose(t *testing.T) {
 	conf := types.OTelConfig(t)
 	conf.Collector.Log.Path = ""
@@ -83,7 +108,7 @@ func TestCollector_Process(t *testing.T) {
 				},
 			},
 			receivers: config.Receivers{
-				HostMetrics: config.HostMetrics{
+				HostMetrics: &config.HostMetrics{
 					CollectionInterval: time.Minute,
 					InitialDelay:       time.Second,
 					Scrapers: &config.HostMetricsScrapers{
@@ -119,7 +144,7 @@ func TestCollector_Process(t *testing.T) {
 				},
 			},
 			receivers: config.Receivers{
-				HostMetrics: config.HostMetrics{
+				HostMetrics: &config.HostMetrics{
 					CollectionInterval: time.Minute,
 					InitialDelay:       time.Second,
 					Scrapers: &config.HostMetricsScrapers{

diff --git a/internal/collector/otelcol.tmpl b/internal/collector/otelcol.tmpl
@@ -1,5 +1,5 @@
 receivers:
-{{- if ne .Receivers.HostMetrics.CollectionInterval 0 }}
+{{- if ne .Receivers.HostMetrics nil }}
   hostmetrics:
     collection_interval: {{ .Receivers.HostMetrics.CollectionInterval }}
     initial_delay: {{ .Receivers.HostMetrics.InitialDelay }}
@@ -148,7 +148,7 @@ service:
   pipelines:
     metrics:
       receivers:
-        {{- if ne .Receivers.HostMetrics.CollectionInterval 0 }}
+        {{- if ne .Receivers.HostMetrics nil }}
         - hostmetrics
         {{- end }}
         {{- range $index, $otlpReceiver := .Receivers.OtlpReceivers }}

diff --git a/internal/collector/settings_test.go b/internal/collector/settings_test.go
@@ -64,7 +64,7 @@ func TestTemplateWrite(t *testing.T) {
 
 	cfg.Collector.Exporters.Debug = &config.DebugExporter{}
 
-	cfg.Collector.Receivers.HostMetrics = config.HostMetrics{
+	cfg.Collector.Receivers.HostMetrics = &config.HostMetrics{
 		CollectionInterval: time.Minute,
 		InitialDelay:       time.Second,
 		Scrapers: &config.HostMetricsScrapers{