Update check-install-version docs (#1343)

Add section about the new Knative Serving release version label, while
keeping the old way in a different section.

Also add an Eventing section. The Eventing components have the release
version label, but it's set to "devel" in 0.6.0.

Author: grantr

docs/install/check-install-version.md

@@ -1,11 +1,33 @@
 ---
-title: "Checking the version of your Knative Serving installation"
+title: "Checking the version of your Knative components"
 linkTitle: "Checking your install version"
 weight: 20
 type: "docs"
 ---
 
-If you want to check what version of Knative serving you have installed, enter
+## Knative Serving (0.4.0 and later)
+
+If your installed version of Knative Serving is v0.4.0 or later, enter the following command:
+
+```bash
+kubectl get deploy -n knative-serving --label-columns=serving.knative.dev/release
+```
+
+This will return a list of deployments in the `knative-serving` namespace and their release versions:
+
+```
+NAME                     DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE       RELEASE
+activator                1         1         1            0           8s        v0.6.0
+autoscaler               1         1         1            0           8s        v0.6.0
+controller               1         1         1            1           6s        v0.6.0
+networking-certmanager   1         1         1            1           6s        v0.6.0
+networking-istio         1         1         1            1           6s        v0.6.0
+webhook                  1         1         1            1           6s        v0.6.0
+```
+
+## Knative Serving (pre-0.4.0)
+
+If your installed version of Knative Serving is earlier than v0.4.0, enter
 the following command:
 
 ```bash
@@ -23,7 +45,7 @@ Pod Template:
   Service Account: controller
   Containers:
     controller:
-      # Link to container used for Knative install
+      # Link to container used to run the Knative Serving controller
       Image: gcr.io/knative-releases/github.com/knative/serving/cmd/controller@sha256:59abc8765d4396a3fc7cac27a932a9cc151ee66343fa5338fb7146b607c6e306
 ```
 
@@ -39,3 +61,40 @@ you have installed will appear in the list as `v0.1.1`, or whatever version you
 have installed:
 
 ![Shows list of tags on container details page; v0.1.1 is the Knative version and is the first tag.](../../images/knative-version.png)
+
+## Knative Eventing
+
+To check what version of Knative serving you have installed, enter
+the following command:
+
+```bash
+kubectl describe deploy eventing-controller --namespace knative-eventing
+```
+
+This will return the description for the `knative-eventing` controller; this
+information contains the link to the container that was used to install Knative:
+
+```yaml
+---
+Pod Template:
+  Labels:           app=eventing-controller
+                    eventing.knative.dev/release=devel
+  Service Account:  eventing-controller
+  Containers:
+   eventing-controller:
+    # Link to container used to run the Knative Eventing controller
+    Image:      gcr.io/knative-releases/github.com/knative/eventing/cmd/controller@sha256:85c010633944c06f4c16253108c2338dba271971b2b5f2d877b8247fa19ff5cb
+```
+
+Copy the full `gcr.io` link to the container and paste it into your browser. If
+you are already signed in to a Google account, you'll be taken to the Google
+Container Registry page for that container in the Google Cloud Platform console.
+If you aren't already signed in, you'll need to sign in to a Google account
+before you can view the container details.
+
+On the container details page, you'll see a section titled "Container
+classification," and in that section is a list of tags. The versions of Knative
+you have installed will appear in the list as `v0.1.1`, or whatever version you
+have installed:
+
+![Shows list of tags on container details page; v0.1.1 is the Knative version and is the first tag.](../../images/knative-version.png)