feat(tracing): Add proxy tracing configuration to control plane helm chart

charts/linkerd-control-plane/templates/destination.yaml

@@ -447,3 +447,6 @@ spec:
       - {{- include "partials.proxy.volumes.service-account-token" . | indent 8 | trimPrefix (repeat 7 " ") }}
       {{ end -}}
       - {{- include "partials.proxy.volumes.identity" . | indent 8 | trimPrefix (repeat 7 " ") }}
+      {{- if .Values.proxy.tracing.enabled -}}
+      - {{- include "partials.proxy.volumes.podinfo" . | indent 8 | trimPrefix (repeat 7 " ") }}
+      {{ end }}

charts/linkerd-control-plane/templates/identity.yaml

@@ -270,8 +270,11 @@ spec:
       {{ if not .Values.cniEnabled -}}
       - {{- include "partials.proxyInit.volumes.xtables" . | indent 8 | trimPrefix (repeat 7 " ") }}
       {{ end -}}
-      {{if .Values.identity.serviceAccountTokenProjection -}}
+      {{ if .Values.identity.serviceAccountTokenProjection -}}
       - {{- include "partials.proxy.volumes.service-account-token" . | indent 8 | trimPrefix (repeat 7 " ") }}
       {{ end -}}
       - {{- include "partials.proxy.volumes.identity" . | indent 8 | trimPrefix (repeat 7 " ") }}
+      {{- if .Values.proxy.tracing.enabled -}}
+      - {{- include "partials.proxy.volumes.podinfo" . | indent 8 | trimPrefix (repeat 7 " ") }}
+      {{ end }}
 {{end -}}

charts/linkerd-control-plane/templates/proxy-injector.yaml

@@ -185,6 +185,9 @@ spec:
       - {{- include "partials.proxy.volumes.service-account-token" . | indent 8 | trimPrefix (repeat 7 " ") }}
       {{ end -}}
       - {{- include "partials.proxy.volumes.identity" . | indent 8 | trimPrefix (repeat 7 " ") }}
+      {{if .Values.proxy.tracing.enable -}}
+      - {{- include "partials.proxy.volumes.podinfo" . | indent 8 | trimPrefix (repeat 7 " ") }}
+      {{ end }}
 ---
 kind: Service
 apiVersion: v1

charts/linkerd-control-plane/values.yaml

@@ -284,6 +284,20 @@ proxy:
   metrics:
       # -- Whether or not to export hostname labels in outbound request metrics.
       hostnameLabels: false
+  # Configures tracing in the proxy and how they are exported
+  tracing:
+    # -- Enables trace collection and export in the proxy
+    enable: false
+    # -- Protocol to export traces with. Currently supported are
+    # "opentelemetry" (default) and "opencensus" (deprecated)
+    protocol: opentelemetry
+    traceServiceName: linkerd-proxy
+    collector:
+      # -- The collector endpoint to send traces to.
+      endpoint: ""
+      # -- The identity of the collector in the linkerd mesh. If the collector
+      # is unmeshed (recommended), this should remain unset.
+      meshIdentity: ""
   inbound:
     server:
       http2:

charts/partials/templates/_proxy.tpl

@@ -144,6 +144,24 @@ env:
   value: 30s
 - name: LINKERD2_PROXY_OUTBOUND_METRICS_HOSTNAME_LABELS
   value: {{ .Values.proxy.metrics.hostnameLabels | quote }}
+{{- if .Values.proxy.tracing.enable -}}
+- name: LINKERD2_PROXY_TRACE_ATTRIBUTES_PATH
+  value: /var/run/linkerd/podinfo/labels
+- name: LINKERD2_PROXY_TRACE_PROTOCOL
+  value: {{ .Values.proxy.tracing.protocol }}
+- name: LINKERD2_PROXY_TRACE_SERVICE_NAME
+  value: {{ .Values.proxy.tracing.traceServiceName }}
+- name: LINKERD2_PROXY_TRACE_COLLECTOR_SVC_ADDR
+  value: {{ .Values.proxy.tracing.collector.endpoint }}
+{{ if .Values.proxy.tracing.collector.meshIdentity -}}
+- name: LINKERD2_PROXY_TRACE_COLLECTOR_SVC_NAME
+  value: {{ .Values.proxy.tracing.collector.meshIdentity }}.serviceaccount.identity.{{.Release.Namespace}}.{{ .Values.clusterDomain }}
+{{ end -}}
+- name: LINKERD2_PROXY_TRACE_EXTRA_ATTRIBUTES
+  value: |
+    k8s.pod.uid=$(_pod_uid)
+    k8s.container.name=$(_pod_containerName)
+{{ end -}}
 {{- /* Configure inbound and outbound parameters, e.g. for HTTP/2 servers. */}}
 {{ range $proxyK, $proxyV := (dict "inbound" .Values.proxy.inbound "outbound" .Values.proxy.outbound) -}}
 {{   range $scopeK, $scopeV := $proxyV -}}
@@ -284,6 +302,10 @@ lifecycle:
 volumeMounts:
 - mountPath: /var/run/linkerd/identity/end-entity
   name: linkerd-identity-end-entity
+{{- if .Values.proxy.tracing.enable }}
+- mountPath: /var/run/linkerd/podinfo
+  name: linkerd-podinfo
+{{- end }}
 {{- if .Values.identity.serviceAccountTokenProjection }}
 - mountPath: /var/run/secrets/tokens
   name: linkerd-identity-token

charts/partials/templates/_volumes.tpl

@@ -4,6 +4,15 @@ emptyDir:
 name: linkerd-identity-end-entity
 {{- end -}}
 
+{{- define "partials.proxy.volumes.podinfo" -}}
+name: linkerd-podinfo
+downwardAPI:
+  items:
+    - path: labels
+      fieldRef:
+        fieldPath: metadata.labels
+{{- end -}}
+
 {{ define "partials.proxyInit.volumes.xtables" -}}
 emptyDir: {}
 name: {{ .Values.proxyInit.xtMountPath.name }}
@@ -38,4 +47,4 @@ projected:
           apiVersion: v1
           fieldPath: metadata.namespace
         path: namespace
-{{- end -}}
+{{- end -}}

charts/patch/templates/patch.json

@@ -103,6 +103,25 @@ structs.
       }
     }
   },
+  {{- if .Values.proxy.tracing.enable }}
+  {
+    "op": "add",
+    "path": "{{$prefix}}/spec/volumes/-",
+    "value": {
+       "downwardAPI": {
+         "items": [
+            {
+              "fieldRef": {
+                "fieldPath": "metadata.labels"
+              },
+              "path": "labels"
+            }
+          ]
+       },
+       "name": "linkerd-podinfo"
+     }
+  },
+  {{- end }}
   {{- if .Values.identity.serviceAccountTokenProjection}}
   {
     "op": "add",

cli/cmd/install_test.go

@@ -119,6 +119,15 @@ func TestRender(t *testing.T) {
 			Metrics: &charts.ProxyMetrics{
 				HostnameLabels: false,
 			},
+			Tracing: &charts.ProxyTracing{
+				Enable:           false,
+				Protocol:         "opentelemetry",
+				TraceServiceName: "linkerd-proxy",
+				Collector: &charts.ProxyTracingCollector{
+					Endpoint:     "",
+					MeshIdentity: "",
+				},
+			},
 			LivenessProbe: &charts.Probe{
 				InitialDelaySeconds: 10,
 				TimeoutSeconds:      1,