Add OTel collector on Agent Startup based on configuration

cmd/agent/package_test.go

@@ -8,9 +8,10 @@ package main
 import (
 	"testing"
 
+	"github.com/nginx/agent/v3/test/helpers"
 	"go.uber.org/goleak"
 )
 
 func TestMain(m *testing.M) {
-	goleak.VerifyTestMain(m)
+	goleak.VerifyTestMain(m, helpers.GoLeakOptions...)
 }

internal/app.go

@@ -48,7 +48,7 @@ func (a *App) Run(ctx context.Context) error {
 		slog.InfoContext(ctx, "Starting NGINX Agent")
 
 		messagePipe := bus.NewMessagePipe(defaultMessagePipeChannelSize)
-		err = messagePipe.Register(defaultQueueSize, plugin.LoadPlugins(agentConfig, slogger))
+		err = messagePipe.Register(defaultQueueSize, plugin.LoadPlugins(agentConfig))
 		if err != nil {
 			slog.ErrorContext(ctx, "Failed to register plugins", "error", err)
 			return

internal/config/config.go

@@ -326,6 +326,7 @@ func getMetrics() *Metrics {
 		ProduceInterval:  viperInstance.GetDuration(MetricsProduceIntervalKey),
 		OTelExporter:     nil,
 		PrometheusSource: nil,
+		Collector:        viperInstance.GetBool(MetricsCollectorKey),
 	}
 
 	if viperInstance.IsSet(MetricsOTelExporterKey) && viperInstance.IsSet(OTelGRPCKey) {

internal/config/flags.go

@@ -37,6 +37,7 @@ var (
 	// child flags saved as vars to enable easier prefixing.
 	MetricsProduceIntervalKey       = pre(MetricsRootKey) + "produce_interval"
 	MetricsOTelExporterKey          = pre(MetricsRootKey) + OTelExporterRoot
+	MetricsCollectorKey             = pre(MetricsRootKey) + "collector"
 	OTelExporterBufferLengthKey     = pre(MetricsOTelExporterKey) + "buffer_length"
 	OTelExporterExportRetryCountKey = pre(MetricsOTelExporterKey) + "export_retry_count"
 	OTelExporterExportIntervalKey   = pre(MetricsOTelExporterKey) + "export_interval"

internal/config/types.go

@@ -52,6 +52,8 @@ type Metrics struct {
 	ProduceInterval  time.Duration     `yaml:"-" mapstructure:"produce_interval"`
 	OTelExporter     *OTelExporter     `yaml:"-" mapstructure:"otel_exporter"`
 	PrometheusSource *PrometheusSource `yaml:"-" mapstructure:"prometheus_source"`
+	// temporary setting to enable the collector
+	Collector bool `yaml:"-" mapstructure:"collector"`
 }
 
 // PrometheusSource is a DataSources implementation

internal/metrics/collector/build.go

@@ -0,0 +1,20 @@
+// Copyright (c) F5, Inc.
+//
+// This source code is licensed under the Apache License, Version 2.0 license found in the
+// LICENSE file in the root directory of this source tree.
+package collector
+
+import (
+	"github.com/nginx/agent/v3/internal/config"
+	"go.opentelemetry.io/collector/component"
+)
+
+// BuildInfo returns all the OTel collector BuildInfo supported
+// based on https://github.com/DataDog/datadog-agent/blob/main/comp/otelcol/collector-contrib/impl/collectorcontrib.go
+func BuildInfo(cfg *config.Config) component.BuildInfo {
+	return component.BuildInfo{
+		Version:     cfg.Version,
+		Command:     "otel-nginx-agent",
+		Description: "NGINX Agent OpenTelemetry Collector",
+	}
+}

internal/metrics/collector/build_test.go

@@ -0,0 +1,21 @@
+// Copyright (c) F5, Inc.
+//
+// This source code is licensed under the Apache License, Version 2.0 license found in the
+// LICENSE file in the root directory of this source tree.
+package collector
+
+import (
+	"testing"
+
+	"github.com/nginx/agent/v3/test/types"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestBuildInfo(t *testing.T) {
+	agentConfig := types.GetAgentConfig()
+	info := BuildInfo(agentConfig)
+
+	assert.Equal(t, agentConfig.Version, info.Version)
+	assert.NotEmpty(t, info.Description)
+	assert.NotNil(t, info.Command)
+}

internal/metrics/collector/config.go

@@ -0,0 +1,76 @@
+// Copyright (c) F5, Inc.
+//
+// This source code is licensed under the Apache License, Version 2.0 license found in the
+// LICENSE file in the root directory of this source tree.
+package collector
+
+import (
+	"log/slog"
+	"os"
+
+	"github.com/nginx/agent/v3/internal/config"
+	"go.opentelemetry.io/collector/confmap"
+	"go.opentelemetry.io/collector/confmap/converter/expandconverter"
+	"go.opentelemetry.io/collector/confmap/provider/envprovider"
+	"go.opentelemetry.io/collector/confmap/provider/fileprovider"
+	"go.opentelemetry.io/collector/confmap/provider/httpprovider"
+	"go.opentelemetry.io/collector/confmap/provider/httpsprovider"
+	"go.opentelemetry.io/collector/confmap/provider/yamlprovider"
+	"go.opentelemetry.io/collector/otelcol"
+)
+
+func OTelCollectorSettings(cfg *config.Config) otelcol.CollectorSettings {
+	return otelcol.CollectorSettings{
+		Factories:               OTelComponentFactories,
+		BuildInfo:               BuildInfo(cfg),
+		DisableGracefulShutdown: false,
+		ConfigProviderSettings:  ConfigProviderSettings(cfg),
+		LoggingOptions:          nil,
+		SkipSettingGRPCLogger:   false,
+	}
+}
+
+// ConfigProviderSettings are the settings to configure the behavior of the ConfigProvider.
+func ConfigProviderSettings(cfg *config.Config) otelcol.ConfigProviderSettings {
+	return otelcol.ConfigProviderSettings{
+		ResolverSettings: confmap.ResolverSettings{
+			ProviderFactories:  createProviderFactories(),
+			ConverterFactories: createConverterFactories(),
+			URIs:               createURIs(cfg),
+		},
+	}
+}
+
+func createProviderFactories() []confmap.ProviderFactory {
+	providerConfig := []confmap.ProviderFactory{
+		envprovider.NewFactory(),
+		fileprovider.NewFactory(),
+		httpprovider.NewFactory(),
+		httpsprovider.NewFactory(),
+		yamlprovider.NewFactory(),
+	}
+
+	return providerConfig
+}
+
+func createConverterFactories() []confmap.ConverterFactory {
+	converterConfig := []confmap.ConverterFactory{
+		expandconverter.NewFactory(),
+	}
+
+	return converterConfig
+}
+
+func createURIs(cfg *config.Config) []string {
+	return []string{getConfig(cfg)}
+}
+
+func getConfig(_ *config.Config) string {
+	val, ex := os.LookupEnv("OPENTELEMETRY_COLLECTOR_CONFIG_FILE")
+	if !ex {
+		return "/tmp/otel-collector-config.yaml"
+	}
+	slog.Info("Using config URI from environment")
+
+	return val
+}

internal/metrics/collector/config_test.go

@@ -0,0 +1,52 @@
+// Copyright (c) F5, Inc.
+//
+// This source code is licensed under the Apache License, Version 2.0 license found in the
+// LICENSE file in the root directory of this source tree.
+package collector
+
+import (
+	"os"
+	"testing"
+
+	"github.com/nginx/agent/v3/test/types"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestOTelCollectorSettings(t *testing.T) {
+	cfg := types.GetAgentConfig()
+
+	settings := OTelCollectorSettings(cfg)
+
+	assert.NotNil(t, settings.Factories, "Factories should not be nil")
+	assert.Equal(t, "otel-nginx-agent", settings.BuildInfo.Command, "BuildInfo command should match")
+	assert.False(t, settings.DisableGracefulShutdown, "DisableGracefulShutdown should be false")
+	assert.NotNil(t, settings.ConfigProviderSettings, "ConfigProviderSettings should not be nil")
+	assert.Nil(t, settings.LoggingOptions, "LoggingOptions should be nil")
+	assert.False(t, settings.SkipSettingGRPCLogger, "SkipSettingGRPCLogger should be false")
+}
+
+func TestConfigProviderSettings(t *testing.T) {
+	cfg := types.GetAgentConfig()
+	settings := ConfigProviderSettings(cfg)
+
+	assert.NotNil(t, settings.ResolverSettings, "ResolverSettings should not be nil")
+	assert.Len(t, settings.ResolverSettings.ProviderFactories, 5, "There should be 5 provider factories")
+	assert.Len(t, settings.ResolverSettings.ConverterFactories, 1, "There should be 1 converter factory")
+	assert.NotEmpty(t, settings.ResolverSettings.URIs, "URIs should not be empty")
+	assert.Equal(t, "/tmp/otel-collector-config.yaml", settings.ResolverSettings.URIs[0], "Default URI should match")
+}
+
+func TestGetConfig(t *testing.T) {
+	// Test with environment variable set
+	t.Setenv("OPENTELEMETRY_COLLECTOR_CONFIG_FILE", "/path/to/config.yaml")
+	defer t.Setenv("OPENTELEMETRY_COLLECTOR_CONFIG_FILE", "")
+
+	configURI := getConfig(nil)
+	assert.Equal(t, "/path/to/config.yaml", configURI, "Config URI should match the environment variable")
+
+	// Test without environment variable set
+	os.Unsetenv("OPENTELEMETRY_COLLECTOR_CONFIG_FILE")
+
+	configURI = getConfig(nil)
+	assert.Equal(t, "/tmp/otel-collector-config.yaml", configURI, "Config URI should match the default value")
+}