feat(plugins/policies): support opentelemetry tracing

Signed-off-by: Benedikt Bongartz <bongartz@klimlive.de>

pkg/plugins/policies/meshtrace/api/v1alpha1/meshtrace.go

@@ -34,12 +34,20 @@ type Conf struct {
 	Tags *[]Tag `json:"tags,omitempty"`
 }
 
-// Only one of zipkin or datadog can be used.
+// Only one of zipkin, datadog or opentelemetry can be used.
 type Backend struct {
 	// Zipkin backend configuration.
 	Zipkin *ZipkinBackend `json:"zipkin,omitempty"`
 	// Datadog backend configuration.
 	Datadog *DatadogBackend `json:"datadog,omitempty"`
+	// OpenTelemetry backend configuration.
+	OpenTelemetry *OpenTelemetryBackend `json:"opentelemetry,omitempty"`
+}
+
+// OpenTelemetry tracing backend configuration.
+type OpenTelemetryBackend struct {
+	// Address of OpenTelemetry collector e.g. otelcol:4317.
+	Endpoint string `json:"url"`
 }
 
 // Zipkin tracing backend configuration.

pkg/plugins/policies/meshtrace/plugin/v1alpha1/plugin.go

@@ -3,6 +3,7 @@ package v1alpha1
 import (
 	net_url "net/url"
 	"strconv"
+	"strings"
 
 	envoy_listener "github.com/envoyproxy/go-control-plane/envoy/config/listener/v3"
 
@@ -168,9 +169,12 @@ func applyToClusters(rules xds.SingleItemRules, rs *xds.ResourceSet, proxy *xds.
 	if backend.Zipkin != nil {
 		endpoint = endpointForZipkin(backend.Zipkin)
 		provider = plugin_xds.ZipkinProviderName
-	} else {
+	} else if backend.Datadog != nil {
 		endpoint = endpointForDatadog(backend.Datadog)
 		provider = plugin_xds.DatadogProviderName
+	} else {
+		endpoint = endpointForOpenTelemetry(backend.OpenTelemetry)
+		provider = plugin_xds.OpenTelemetryProviderName
 	}
 
 	res, err := clusters.NewClusterBuilder(proxy.APIVersion).
@@ -200,6 +204,19 @@ func endpointForZipkin(cfg *api.ZipkinBackend) *xds.Endpoint {
 	}
 }
 
+func endpointForOpenTelemetry(cfg *api.OpenTelemetryBackend) *xds.Endpoint {
+	target := strings.Split(cfg.Endpoint, ":")
+	port := uint32(4317) // default gRPC port
+	if len(target) > 1 {
+		val, _ := strconv.ParseInt(target[1], 10, 32)
+		port = uint32(val)
+	}
+	return &xds.Endpoint{
+		Target: target[0],
+		Port:   port,
+	}
+}
+
 func endpointForDatadog(cfg *api.DatadogBackend) *xds.Endpoint {
 	url, _ := net_url.ParseRequestURI(cfg.Url)
 	port, _ := strconv.ParseInt(url.Port(), 10, 32)

pkg/plugins/policies/meshtrace/plugin/v1alpha1/plugin_test.go

@@ -239,6 +239,135 @@ var _ = Describe("MeshTrace", func() {
                                     portValue: 9411
             name: meshtrace:zipkin
             type: STRICT_DNS
+`},
+		}),
+		Entry("inbound/outbound for opentelemetry", testCase{
+			resources: inboundAndOutbound(),
+			singleItemRules: core_xds.SingleItemRules{
+				Rules: []*core_xds.Rule{
+					{
+						Subset: []core_xds.Tag{},
+						Conf: api.Conf{
+							Tags: &[]api.Tag{
+								{Name: "app", Literal: pointer.To("backend")},
+								{Name: "app_code", Header: &api.HeaderTag{Name: "app_code"}},
+								{Name: "client_id", Header: &api.HeaderTag{Name: "client_id", Default: pointer.To("none")}},
+							},
+							Sampling: &api.Sampling{
+								Overall: pointer.To(intstr.FromInt(10)),
+								Client:  pointer.To(intstr.FromInt(20)),
+								Random:  pointer.To(intstr.FromInt(50)),
+							},
+							Backends: &[]api.Backend{{
+								OpenTelemetry: &api.OpenTelemetryBackend{
+									Endpoint:               "jaeger-collector.mesh-observability:4317",
+								},
+							}},
+						},
+					},
+				}},
+			expectedListeners: []string{`
+            address:
+              socketAddress:
+                address: 127.0.0.1
+                portValue: 17777
+            enableReusePort: false
+            filterChains:
+            - filters:
+              - name: envoy.filters.network.http_connection_manager
+                typedConfig:
+                  '@type': type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
+                  httpFilters:
+                  - name: envoy.filters.http.router
+                    typedConfig:
+                      '@type': type.googleapis.com/envoy.extensions.filters.http.router.v3.Router
+                  statPrefix: "127_0_0_1_17777"
+                  tracing:
+                      clientSampling:
+                          value: 20
+                      customTags:
+                          - literal:
+                              value: backend
+                            tag: app
+                          - requestHeader:
+                              name: app_code
+                            tag: app_code
+                          - requestHeader:
+                              defaultValue: none
+                              name: client_id
+                            tag: client_id
+                      overallSampling:
+                          value: 10
+                      provider:
+                          name: envoy.tracers.opentelemetry
+                          typedConfig:
+                              '@type': type.googleapis.com/envoy.config.trace.v3.OpenTelemetryConfig
+                              grpcService: 
+                                  envoyGrpc:
+                                      clusterName: meshtrace:opentelemetry
+                              serviceName: backend
+                      randomSampling:
+                          value: 50
+            name: inbound:127.0.0.1:17777
+            trafficDirection: INBOUND`, `
+            address:
+              socketAddress:
+                address: 127.0.0.1
+                portValue: 27777
+            filterChains:
+            - filters:
+              - name: envoy.filters.network.http_connection_manager
+                typedConfig:
+                  '@type': type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
+                  httpFilters:
+                  - name: envoy.filters.http.router
+                    typedConfig:
+                      '@type': type.googleapis.com/envoy.extensions.filters.http.router.v3.Router
+                  statPrefix: "127_0_0_1_27777"
+                  tracing:
+                      clientSampling:
+                          value: 20
+                      customTags:
+                          - literal:
+                              value: backend
+                            tag: app
+                          - requestHeader:
+                              name: app_code
+                            tag: app_code
+                          - requestHeader:
+                              defaultValue: none
+                              name: client_id
+                            tag: client_id
+                      overallSampling:
+                          value: 10
+                      provider:
+                          name: envoy.tracers.opentelemetry
+                          typedConfig:
+                              '@type': type.googleapis.com/envoy.config.trace.v3.OpenTelemetryConfig
+                              grpcService: 
+                                  envoyGrpc:
+                                      clusterName: meshtrace:opentelemetry
+                              serviceName: backend
+                      randomSampling:
+                          value: 50
+            name: outbound:127.0.0.1:27777
+            trafficDirection: OUTBOUND
+`},
+			expectedClusters: []string{`
+            altStatName: meshtrace_opentelemetry
+            connectTimeout: 10s
+            dnsLookupFamily: V4_ONLY
+            loadAssignment:
+                clusterName: meshtrace:opentelemetry
+                endpoints:
+                    - lbEndpoints:
+                        - endpoint:
+                            address:
+                                socketAddress:
+                                    address: jaeger-collector.mesh-observability
+                                    portValue: 4317
+            name: meshtrace:opentelemetry
+            type: STRICT_DNS
 `},
 		}),
 		Entry("inbound/outbound for datadog", testCase{

pkg/plugins/policies/meshtrace/plugin/xds/configurer.go

@@ -35,8 +35,9 @@ type Configurer struct {
 var _ v3.FilterChainConfigurer = &Configurer{}
 
 const (
-	ZipkinProviderName  = "zipkin"
-	DatadogProviderName = "datadog"
+	ZipkinProviderName        = "zipkin"
+	DatadogProviderName       = "datadog"
+	OpenTelemetryProviderName = "opentelemetry"
 )
 
 func (c *Configurer) Configure(filterChain *envoy_listener.FilterChain) error {
@@ -94,6 +95,14 @@ func (c *Configurer) Configure(filterChain *envoy_listener.FilterChain) error {
 			hcm.Tracing.Provider = tracing
 		}
 
+		if backend.OpenTelemetry != nil {
+			tracing, err := c.opentelemetryConfig(GetTracingClusterName(OpenTelemetryProviderName))
+			if err != nil {
+				return err
+			}
+			hcm.Tracing.Provider = tracing
+		}
+
 		return nil
 	})
 }
@@ -127,6 +136,30 @@ func (c *Configurer) datadogConfig(clusterName string) (*envoy_trace.Tracing_Htt
 	return tracingConfig, nil
 }
 
+func (c *Configurer) opentelemetryConfig(clusterName string) (*envoy_trace.Tracing_Http, error) {
+	otelConfig := envoy_trace.OpenTelemetryConfig{
+		ServiceName: c.Service,
+		GrpcService: &envoy_core.GrpcService{
+			TargetSpecifier: &envoy_core.GrpcService_EnvoyGrpc_{
+				EnvoyGrpc: &envoy_core.GrpcService_EnvoyGrpc{
+					ClusterName: clusterName,
+				},
+			},
+		},
+	}
+	otelConfigAny, err := proto.MarshalAnyDeterministic(&otelConfig)
+	if err != nil {
+		return nil, err
+	}
+	tracingConfig := &envoy_trace.Tracing_Http{
+		Name: "envoy.tracers.opentelemetry",
+		ConfigType: &envoy_trace.Tracing_Http_TypedConfig{
+			TypedConfig: otelConfigAny,
+		},
+	}
+	return tracingConfig, nil
+}
+
 func (c *Configurer) zipkinConfig(clusterName string) (*envoy_trace.Tracing_Http, error) {
 	zipkin := pointer.Deref(c.Conf.Backends)[0].Zipkin
 	url, err := net_url.ParseRequestURI(zipkin.Url)