feat(inject): Populate proxy tracing values from annotations

charts/linkerd-control-plane/values.yaml

@@ -286,6 +286,13 @@ proxy:
     # -- Enables trace collection and export in the proxy
     enabled: false
     traceServiceName: linkerd-proxy
+    # -- Additional labels to add to the traces emitted by the proxy.
+    # These should generally not be set globally, and instead overridden on
+    # individual workloads via `resource.opentelemetry.io/<label>` annotations.
+    labels:
+      k8s.pod.ip: "$(_pod_ip)"
+      k8s.pod.uid: "$(_pod_uid)"
+      k8s.container.name: "$(_pod_containerName)"
     collector:
       # -- The collector endpoint to send traces to.
       endpoint: ""

charts/partials/templates/_proxy.tpl

@@ -172,9 +172,9 @@ env:
   value: {{ .Values.proxy.tracing.collector.meshIdentity.serviceAccountName }}.{{ .Values.proxy.tracing.collector.meshIdentity.namespace }}.serviceaccount.identity.{{.Release.Namespace}}.{{ .Values.clusterDomain }}
 - name: LINKERD2_PROXY_TRACE_EXTRA_ATTRIBUTES
   value: |
-    k8s.pod.ip=$(_pod_ip)
-    k8s.pod.uid=$(_pod_uid)
-    k8s.container.name=$(_pod_containerName)
+    {{- range $k, $v := .Values.proxy.tracing.labels }}
+    {{ $k }}={{ $v }}
+    {{- end }}
 {{ end -}}
 {{/* Configure inbound and outbound parameters, e.g. for HTTP/2 servers. */ -}}
 {{ range $proxyK, $proxyV := (dict "inbound" .Values.proxy.inbound "outbound" .Values.proxy.outbound) -}}

cli/cmd/install_test.go

@@ -126,7 +126,12 @@ func TestRender(t *testing.T) {
 				HostnameLabels: false,
 			},
 			Tracing: &charts.Tracing{
-				Enabled:          false,
+				Enabled: false,
+				Labels: map[string]string{
+					"k8s.pod.ip":         "$(_pod_ip)",
+					"k8s.pod.uid":        "$(_pod_uid)",
+					"k8s.container.name": "$(_pod_containerName)",
+				},
 				TraceServiceName: "linkerd-proxy",
 				Collector: &charts.TracingCollector{
 					Endpoint: "",
@@ -263,6 +268,16 @@ func TestRender(t *testing.T) {
 	withCustomDestinationGetNetsValues.ClusterNetworks = "10.0.0.0/8,100.64.0.0/10,172.0.0.0/8"
 	addFakeTLSSecrets(withCustomDestinationGetNetsValues)
 
+	tracingValues, err := testInstallOptions()
+	if err != nil {
+		t.Fatalf("Unexpected error: %v\n", err)
+	}
+	tracingValues.Proxy.Tracing.Enabled = true
+	tracingValues.Proxy.Tracing.Collector.Endpoint = "tracing.foo:4317"
+	tracingValues.Proxy.Tracing.Collector.MeshIdentity.ServiceAccountName = "default"
+	tracingValues.Proxy.Tracing.Collector.MeshIdentity.Namespace = "foo"
+	addFakeTLSSecrets(tracingValues)
+
 	testCases := []struct {
 		values         *charts.Values
 		goldenFileName string
@@ -282,6 +297,7 @@ func TestRender(t *testing.T) {
 		{defaultValues, "install_values_file.golden", values.Options{ValueFiles: []string{filepath.Join("testdata", "install_config.yaml")}}},
 		{defaultValues, "install_default_token.golden", values.Options{Values: []string{"identity.serviceAccountTokenProjection=false"}}},
 		{gidValues, "install_gid_output.golden", values.Options{}},
+		{tracingValues, "install_tracing.golden", values.Options{}},
 	}
 
 	for i, tc := range testCases {