Update application labeling guidance (istio#14095)

howardjohn · Eric Van Norman · web-flow · commit 4129b7fd2fa1 · 2023-11-04T17:41:50.000-07:00
* Update application labeling guidance Fixes istio/istio#10724 * Update content/en/docs/ops/deployment/requirements/index.md Co-authored-by: Eric Van Norman <ericvn@us.ibm.com> --------- Co-authored-by: Eric Van Norman <ericvn@us.ibm.com>
diff --git a/content/en/docs/ops/deployment/requirements/index.md b/content/en/docs/ops/deployment/requirements/index.md
@@ -64,17 +64,12 @@ To be part of a mesh, Kubernetes pods must satisfy the following requirements:
     policies for your service account, your pods have permission to run the Istio init containers.
     Otherwise, you will need to [provide the permission](https://kubernetes.io/docs/concepts/policy/pod-security-policy/#authorizing-policies).
 
-- **Pods with app and version labels**: We recommend adding an explicit
-  `app` label and `version` label to the specification of the pods deployed using
-  a Kubernetes `Deployment`. The `app` and `version` labels add contextual information
-  to the metrics and telemetry that Istio collects.
+- **Pod labels**: We recommend explicitly declaring pods with an application identifier and version by using a pod label.
+  These labels add contextual information to the metrics and telemetry that Istio collects.
+  Each of these values are read from multiple labels ordered from highest to lowest precedence:
 
-    - The `app` label: Each deployment should have a distinct
-      `app` label with a meaningful value. The `app` label is used to add
-      contextual information in distributed tracing.
-
-    - The `version` label: This label indicates the version of the application
-      corresponding to the particular deployment.
+    - Application name: `service.istio.io/canonical-name`, `app.kubernetes.io/name`, or `app`.
+    - Application version: `service.istio.io/canonical-revision`, `app.kubernetes.io/version`, or `version`.
 
 - **Named service ports**: Service ports may optionally be named to explicitly specify a protocol.
   See [Protocol Selection](/docs/ops/configuration/traffic-management/protocol-selection/) for
