Merge branch 'eddy/k8-lib-injection' of github.com:DataDog/documentation into eddy/k8-lib-injection

kayayarai · kayayarai · commit 8ba0623f6e72 · 2022-09-02T11:44:45.000-06:00
diff --git a/content/en/containers/cluster_agent/admission_controller.md b/content/en/containers/cluster_agent/admission_controller.md
@@ -128,29 +128,42 @@ Finally, run the following commands:
 - `kubectl apply -f agent-services.yaml`
 - `kubectl apply -f cluster-agent-deployment.yaml`
 
-### APM and DogStatsD
 
-To configure and inject APM tracers libraries and DogstatsD clients automatically:
+### APM
+You can configure the Cluster Agent (version 7.39 and higher) to inject APM tracing libraries automatically.
 
+After you install the Cluster Agent, do one of the following:
 - Add the label `admission.datadoghq.com/enabled: "true"` to your pod.
 - Configure the Cluster Agent admission controller by setting `mutateUnlabelled` (or `DD_ADMISSION_CONTROLLER_MUTATE_UNLABELLED`, depending on your configuration method) to `true`.
 
-To opt-in your container for library injection, use Pod annotations inside your application's YAML file to specify which language tracers and should be injected, along with their versions.
+To opt-in your container for library injection, use Pod annotations inside your application's YAML file to specify language tracers and versions.
+
 
 The annotations are a `key: value` pair in the following format:
 
 ```yaml
-admission.datadoghq.com/<language>-tracer.version: <tracer-version>
+datadoghq.com/<language>-lib.version: <lib-version>
+```
+
+Adding a this annotation results in the injection of the tracer library for that language and version into the containerized application.
+Currently, the list of possible lib values include `java`, `js` and `python` respectively.
+
+For example to inject the latest Java tracer:
+
+```yaml
+annotations:
+    datadoghq.com/java-lib.version: "latest"
 ```
 
-Adding a this annotation means the tracer library for that language and version is injected into the containerized application. You can add several `<language>-tracer.version` annotations to inject multiple language tracers into one container.
+**Note**: Use caution specifying `latest` as major library releases can introduce breaking changes.
 
-For example to inject the latest Java tracer and Ruby tracer version 1.4.0:
+Although it's an uncommon scenario, you can add multiple `<language>-lib.version` annotations to inject multiple language tracers into one container.
 
+For example to inject the latest Java tracer and Node tracer v3.0.0:
 ```yaml
 annotations:
-    admission.datadoghq.com/java-tracer.version: "latest"
-    admission.datadoghq.com/ruby-tracer.version: "1.4.0"
+    datadoghq.com/java-lib.version: "latest"
+    datadoghq.com/js-lib.version: "3.0.0"
 ```
 
 To prevent pods from receiving environment variables, add the label `admission.datadoghq.com/enabled: "false"`. This works even if you set `mutateUnlabelled: true`.
@@ -166,6 +179,11 @@ Possible options:
 | `false`          | `admission.datadoghq.com/enabled=true`  | Yes       |
 | `false`          | `admission.datadoghq.com/enabled=false` | No        |
 
+### DogStatsD
+To configure DogstatsD clients or other APM libraries that does not support library injection at this time, inject the environment variables `DD_AGENT_HOST` and `DD_ENTITY_ID` by using one of the following:
+- Add the label `admission.datadoghq.com/enabled: "true"` to your pod.
+- Configure the Cluster Agent admission controller by setting `mutateUnlabelled` (or `DD_ADMISSION_CONTROLLER_MUTATE_UNLABELLED`, depending on your configuration method) to `true`.
+
 
 #### Order of priority
 The Datadog admission controller does not inject the environment variables `DD_VERSION`, `DD_ENV`, and `DD_SERVICE` if they already exist.
