Add ability to auto-instrument with the OTel Java SDK

.gitignore

@@ -1201,3 +1201,6 @@ test/integration/components/testserver_1.17/vendor/gopkg.in/yaml.v2/writerc.go
 test/integration/components/testserver_1.17/vendor/gopkg.in/yaml.v2/yaml.go
 test/integration/components/testserver_1.17/vendor/gopkg.in/yaml.v2/yamlh.go
 test/integration/components/testserver_1.17/vendor/gopkg.in/yaml.v2/yamlprivateh.go
+*_bpfel.go
+*_bpfel.o
+pkg/internal/otelsdk/grafana-opentelemetry-java.jar

Makefile

@@ -183,12 +183,19 @@ update-offsets: prereqs
 
 # Prefer docker-generate instead, as it's able to perform a parallel build
 .PHONY: generate
-generate: export BPF_CLANG := $(CLANG)
-generate: export BPF_CFLAGS := $(CFLAGS)
-generate: export BPF2GO := $(BPF2GO)
-generate: bpf2go
+generate: bpf-generate javaagent-generate
+
+.PHONY: bpf-generate
+bpf-generate: export BPF_CLANG := $(CLANG)
+bpf-generate: export BPF_CFLAGS := $(CFLAGS)
+bpf-generate: export BPF2GO := $(BPF2GO)
+bpf-generate: bpf2go
 	@echo "### Generating BPF Go bindings"
-	go generate ./pkg/...
+	grep -rlI "BPF2GO" pkg/internal/ | xargs -P 0 -n 1 go generate
+
+.PHONY: javaagent-generate
+javaagent-generate:
+	@go generate pkg/internal/otelsdk/sdk_inject.go
 
 .PHONY: docker-generate
 docker-generate:

generator.Dockerfile

@@ -3,7 +3,7 @@ FROM golang:alpine3.21 AS base
 ARG EBPF_VER
 
 # Installs dependencies that are required to compile eBPF programs
-RUN apk add clang llvm19
+RUN apk add clang llvm19 curl
 RUN apk cache purge
 RUN go install github.com/cilium/ebpf/cmd/bpf2go@$EBPF_VER
 
@@ -21,6 +21,8 @@ export BPF_CFLAGS="-O2 -g -Wall -Werror"
 
 export GENFILES=\$1
 
+go generate pkg/internal/otelsdk/sdk_inject.go
+
 if [ -z "\$GENFILES" ]; then
 	echo No genfiles specified - regenerating everything
 	grep -rlI "BPF2GO" pkg/internal/ | xargs -P 0 -n 1 go generate

go.mod

@@ -1,6 +1,6 @@
 module github.com/grafana/beyla/v2
 
-go 1.23.0
+go 1.23.2
 
 require (
 	github.com/AlessandroPomponio/go-gibberish v0.0.0-20191004143433-a2d4156f0396
@@ -17,6 +17,7 @@ require (
 	github.com/google/uuid v1.6.0
 	github.com/gorilla/mux v1.8.1
 	github.com/grafana/go-offsets-tracker v0.1.7
+	github.com/grafana/jvmtools v0.0.3
 	github.com/hashicorp/go-version v1.7.0
 	github.com/hashicorp/golang-lru/v2 v2.0.7
 	github.com/ianlancetaylor/demangle v0.0.0-20240912202439-0a2b6291aafd

go.sum

@@ -110,6 +110,8 @@ github.com/gorilla/websocket v1.5.0 h1:PPwGk2jz7EePpoHN/+ClbZu8SPxiqlu12wZP/3sWm
 github.com/gorilla/websocket v1.5.0/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 github.com/grafana/go-offsets-tracker v0.1.7 h1:2zBQ7iiGzvyXY7LA8kaaSiEqH/Yx82UcfRabbY5aOG4=
 github.com/grafana/go-offsets-tracker v0.1.7/go.mod h1:qcQdu7zlUKIFNUdBJlLyNHuJGW0SKWKjkrN6jtt+jds=
+github.com/grafana/jvmtools v0.0.3 h1:4uPquep5v+54Z04OQYOCldrv2SR42IRagHQXrNHsc4g=
+github.com/grafana/jvmtools v0.0.3/go.mod h1:b0tiPI5zNyIuPUz2DwvxUCI+5bFoG7A4i47F9sc8w98=
 github.com/grpc-ecosystem/grpc-gateway/v2 v2.25.1 h1:VNqngBF40hVlDloBruUehVYC3ArSgIyScOAyMRqBxRg=
 github.com/grpc-ecosystem/grpc-gateway/v2 v2.25.1/go.mod h1:RBRO7fro65R6tjKzYgLAFo0t1QEXY1Dp+i/bvpRiqiQ=
 github.com/hashicorp/go-version v1.7.0 h1:5tqGy27NaOTB8yJKUZELlFAS/LTKJkrmONwQKeRZfjY=

pkg/config/ebpf_tracer.go

@@ -59,4 +59,7 @@ type EBPFTracer struct {
 
 	// Enables debug printing of the protocol data
 	ProtocolDebug bool `yaml:"protocol_debug_print" env:"BEYLA_PROTOCOL_DEBUG_PRINT"`
+
+	// Enables Java instrumentation with the OpenTelemetry JDK Agent
+	UseOTelSDKForJava bool `yaml:"use_otel_sdk_for_java" env:"BEYLA_USE_OTEL_SDK_FOR_JAVA"`
 }

pkg/export/otel/common.go

@@ -45,6 +45,7 @@ const (
 	envProtocol        = "OTEL_EXPORTER_OTLP_PROTOCOL"
 	envHeaders         = "OTEL_EXPORTER_OTLP_HEADERS"
 	envTracesHeaders   = "OTEL_EXPORTER_OTLP_TRACES_HEADERS"
+	envMetricsHeaders  = "OTEL_EXPORTER_OTLP_METRICS_HEADERS"
 	envResourceAttrs   = "OTEL_RESOURCE_ATTRIBUTES"
 )
 
@@ -229,8 +230,7 @@ type otlpOptions struct {
 	BaseURLPath   string
 	URLPath       string
 	SkipTLSVerify bool
-	HTTPHeaders   map[string]string
-	GRPCHeaders   map[string]string
+	Headers       map[string]string
 }
 
 func (o *otlpOptions) AsMetricHTTP() []otlpmetrichttp.Option {
@@ -246,8 +246,8 @@ func (o *otlpOptions) AsMetricHTTP() []otlpmetrichttp.Option {
 	if o.SkipTLSVerify {
 		opts = append(opts, otlpmetrichttp.WithTLSClientConfig(&tls.Config{InsecureSkipVerify: true}))
 	}
-	if len(o.HTTPHeaders) > 0 {
-		opts = append(opts, otlpmetrichttp.WithHeaders(o.HTTPHeaders))
+	if len(o.Headers) > 0 {
+		opts = append(opts, otlpmetrichttp.WithHeaders(o.Headers))
 	}
 	return opts
 }
@@ -262,8 +262,8 @@ func (o *otlpOptions) AsMetricGRPC() []otlpmetricgrpc.Option {
 	if o.SkipTLSVerify {
 		opts = append(opts, otlpmetricgrpc.WithTLSCredentials(credentials.NewTLS(&tls.Config{InsecureSkipVerify: true})))
 	}
-	if len(o.GRPCHeaders) > 0 {
-		opts = append(opts, otlpmetricgrpc.WithHeaders(o.GRPCHeaders))
+	if len(o.Headers) > 0 {
+		opts = append(opts, otlpmetricgrpc.WithHeaders(o.Headers))
 	}
 	return opts
 }
@@ -281,8 +281,8 @@ func (o *otlpOptions) AsTraceHTTP() []otlptracehttp.Option {
 	if o.SkipTLSVerify {
 		opts = append(opts, otlptracehttp.WithTLSClientConfig(&tls.Config{InsecureSkipVerify: true}))
 	}
-	if len(o.HTTPHeaders) > 0 {
-		opts = append(opts, otlptracehttp.WithHeaders(o.HTTPHeaders))
+	if len(o.Headers) > 0 {
+		opts = append(opts, otlptracehttp.WithHeaders(o.Headers))
 	}
 	return opts
 }
@@ -297,8 +297,8 @@ func (o *otlpOptions) AsTraceGRPC() []otlptracegrpc.Option {
 	if o.SkipTLSVerify {
 		opts = append(opts, otlptracegrpc.WithTLSCredentials(credentials.NewTLS(&tls.Config{InsecureSkipVerify: true})))
 	}
-	if len(o.GRPCHeaders) > 0 {
-		opts = append(opts, otlptracegrpc.WithHeaders(o.GRPCHeaders))
+	if len(o.Headers) > 0 {
+		opts = append(opts, otlptracegrpc.WithHeaders(o.Headers))
 	}
 	return opts
 }
@@ -359,7 +359,7 @@ func (l *LogrAdaptor) WithName(name string) logr.LogSink {
 	return &LogrAdaptor{inner: l.inner.With("name", name)}
 }
 
-func headersFromEnv(varName string) map[string]string {
+func HeadersFromEnv(varName string) map[string]string {
 	headers := map[string]string{}
 
 	addToMap := func(k string, v string) {
@@ -404,3 +404,19 @@ func ResourceAttrsFromEnv(svc *svc.Attrs) []attribute.KeyValue {
 	parseOTELEnvVar(svc, envResourceAttrs, apply)
 	return otelResourceAttrs
 }
+
+func ResolveOTLPEndpoint(endpoint, common string, grafana *GrafanaOTLP) (string, bool) {
+	if endpoint != "" {
+		return endpoint, false
+	}
+
+	if common != "" {
+		return common, true
+	}
+
+	if grafana != nil && grafana.CloudZone != "" && grafana.Endpoint() != "" {
+		return grafana.Endpoint(), true
+	}
+
+	return "", false
+}

pkg/export/otel/common_test.go

@@ -186,3 +186,45 @@ func TestParseOTELEnvVar_nil(t *testing.T) {
 
 	assert.True(t, reflect.DeepEqual(actual, map[string]string{}))
 }
+
+func TestResolveOTLPEndpoint(t *testing.T) {
+	grafana1 := GrafanaOTLP{
+		CloudZone: "foo",
+	}
+
+	const grafanaEndpoint = "https://otlp-gateway-foo.grafana.net/otlp"
+
+	grafana2 := GrafanaOTLP{}
+
+	type expected struct {
+		e      string
+		common bool
+	}
+
+	type testCase struct {
+		endpoint string
+		common   string
+		grafana  *GrafanaOTLP
+		expected expected
+	}
+
+	testCases := []testCase{
+		{endpoint: "e1", common: "c1", grafana: nil, expected: expected{e: "e1", common: false}},
+		{endpoint: "e1", common: "", grafana: nil, expected: expected{e: "e1", common: false}},
+		{endpoint: "", common: "c1", grafana: nil, expected: expected{e: "c1", common: true}},
+		{endpoint: "", common: "", grafana: nil, expected: expected{e: "", common: false}},
+		{endpoint: "e1", common: "c1", grafana: &grafana1, expected: expected{e: "e1", common: false}},
+		{endpoint: "", common: "c1", grafana: &grafana1, expected: expected{e: "c1", common: true}},
+		{endpoint: "", common: "", grafana: &grafana1, expected: expected{e: grafanaEndpoint, common: true}},
+		{endpoint: "", common: "", grafana: &grafana2, expected: expected{e: "", common: false}},
+	}
+
+	for _, tc := range testCases {
+		t.Run(fmt.Sprint(tc), func(t *testing.T) {
+			ep, common := ResolveOTLPEndpoint(tc.endpoint, tc.common, tc.grafana)
+
+			assert.Equal(t, ep, tc.expected.e)
+			assert.Equal(t, common, tc.expected.common)
+		})
+	}
+}

pkg/export/otel/grafana.go

@@ -77,18 +77,18 @@ func (cfg *GrafanaOTLP) AuthHeader() string {
 	return "Basic " + base64.StdEncoding.EncodeToString([]byte(cfg.InstanceID+":"+cfg.APIKey))
 }
 
+func (cfg *GrafanaOTLP) HasAuth() bool {
+	return cfg.InstanceID != "" && cfg.APIKey != ""
+}
+
 func (cfg *GrafanaOTLP) setupOptions(opt *otlpOptions) {
 	if cfg == nil {
 		return
 	}
-	if cfg.InstanceID != "" && cfg.APIKey != "" {
-		if opt.HTTPHeaders == nil {
-			opt.HTTPHeaders = map[string]string{}
-		}
-		opt.HTTPHeaders["Authorization"] = cfg.AuthHeader()
-		if opt.GRPCHeaders == nil {
-			opt.GRPCHeaders = map[string]string{}
+	if cfg.HasAuth() {
+		if opt.Headers == nil {
+			opt.Headers = map[string]string{}
 		}
-		opt.GRPCHeaders["Authorization"] = cfg.AuthHeader()
+		opt.Headers["Authorization"] = cfg.AuthHeader()
 	}
 }

pkg/export/otel/metrics.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"log/slog"
+	"maps"
 	"net/url"
 	"os"
 	"slices"
@@ -144,6 +145,10 @@ func (m *MetricsConfig) GuessProtocol() Protocol {
 	return ProtocolHTTPProtobuf
 }
 
+func (m *MetricsConfig) OTLPMetricsEndpoint() (string, bool) {
+	return ResolveOTLPEndpoint(m.MetricsEndpoint, m.CommonEndpoint, m.Grafana)
+}
+
 // EndpointEnabled specifies that the OTEL metrics node is enabled if and only if
 // either the OTEL endpoint and OTEL metrics endpoint is defined.
 // If not enabled, this node won't be instantiated
@@ -963,7 +968,7 @@ func (mr *MetricsReporter) reportMetrics(input <-chan []request.Span) {
 }
 
 func getHTTPMetricEndpointOptions(cfg *MetricsConfig) (otlpOptions, error) {
-	opts := otlpOptions{}
+	opts := otlpOptions{Headers: map[string]string{}}
 	log := mlog().With("transport", "http")
 	murl, isCommon, err := parseMetricsEndpoint(cfg)
 	if err != nil {
@@ -996,12 +1001,14 @@ func getHTTPMetricEndpointOptions(cfg *MetricsConfig) (otlpOptions, error) {
 	}
 
 	cfg.Grafana.setupOptions(&opts)
+	maps.Copy(opts.Headers, HeadersFromEnv(envHeaders))
+	maps.Copy(opts.Headers, HeadersFromEnv(envMetricsHeaders))
 
 	return opts, nil
 }
 
 func getGRPCMetricEndpointOptions(cfg *MetricsConfig) (otlpOptions, error) {
-	opts := otlpOptions{}
+	opts := otlpOptions{Headers: map[string]string{}}
 	log := mlog().With("transport", "grpc")
 	murl, _, err := parseMetricsEndpoint(cfg)
 	if err != nil {
@@ -1020,6 +1027,11 @@ func getGRPCMetricEndpointOptions(cfg *MetricsConfig) (otlpOptions, error) {
 		log.Debug("Setting InsecureSkipVerify")
 		opts.SkipTLSVerify = true
 	}
+
+	cfg.Grafana.setupOptions(&opts)
+	maps.Copy(opts.Headers, HeadersFromEnv(envHeaders))
+	maps.Copy(opts.Headers, HeadersFromEnv(envMetricsHeaders))
+
 	return opts, nil
 }
 
@@ -1030,15 +1042,7 @@ func getGRPCMetricEndpointOptions(cfg *MetricsConfig) (otlpOptions, error) {
 // If, by some reason, Grafana changes its OTLP Gateway URL in a distant future, you can still point to the
 // correct URL with the OTLP_EXPORTER_... variables.
 func parseMetricsEndpoint(cfg *MetricsConfig) (*url.URL, bool, error) {
-	isCommon := false
-	endpoint := cfg.MetricsEndpoint
-	if endpoint == "" {
-		isCommon = true
-		endpoint = cfg.CommonEndpoint
-		if endpoint == "" && cfg.Grafana != nil && cfg.Grafana.CloudZone != "" {
-			endpoint = cfg.Grafana.Endpoint()
-		}
-	}
+	endpoint, isCommon := cfg.OTLPMetricsEndpoint()
 
 	murl, err := url.Parse(endpoint)
 	if err != nil {