Replace service.yaml with the correct contents (#1378)

* Replace service.yaml with the correct contents

* edit for clarity, domain as req., PR #1202

* Update docs/serving/samples/gitwebhook-go/README.md

Co-Authored-By: RichieEscarez <[email protected]>

* Apply suggestions from code review

Co-Authored-By: RichieEscarez <[email protected]>

Author: 2 people

docs/serving/samples/gitwebhook-go/README.md

@@ -3,13 +3,23 @@ webhook.
 
 ## Before you begin
 
-- A Kubernetes cluster with Knative installed. Follow the
-  [installation instructions](../../../install/README.md) if you need to create
-  one.
-- [Docker](https://www.docker.com) installed and running on your local machine,
-  and a Docker Hub account configured (we'll use it for a container registry).
-- An account on [GitHub](https://github.com) with read/write access to a
-  repository.
+You must meet the following requirements to run this sample:
+
+- Own a public domain. For example, you can create a domain with
+  [Google Domains](https://domains.google/).
+- A Kubernetes cluster running with the following:
+  - Knative Serving must be installed. For details about
+    setting up a Knative cluster, see the
+    [installation guides](../../../install/README.md).
+  - Your Knative cluster must be 
+    [configured to use your custom domain](../../using-a-custom-domain.md).
+  - You must ensure that your Knative cluster uses a static IP address:
+    - For Google Kubernetes Engine, see 
+      [assigning a static IP address](../../gke-assigning-static-ip-address.md).
+    - For other cloud providers, refer to your provider's documentation.
+- An installed version of [Docker](https://www.docker.com).
+- A [Docker Hub account](https://hub.docker.com/) to which you are able to
+  upload your sample's container image.
 
 ## Build the sample code
 
@@ -20,7 +30,7 @@ webhook.
    cd knative-docs/serving/samples/gitwebhook-go
    ```
 
-1. Use Docker to build a container image for this service. Replace `username`
+1. Use Docker to build a container image for this service. Replace `{DOCKER_HUB_USERNAME}`
    with your Docker Hub username in the following commands.
 
    ```shell
@@ -33,14 +43,14 @@ webhook.
    docker push ${DOCKER_HUB_USERNAME}/gitwebhook-go
    ```
 
-1. Create a secret that holds two values from GitHub, a personal access token
-   used to make API requests to GitHub, and a webhook secret, used to validate
-   incoming requests.
+1. Create a secret that holds two values from GitHub:
+    - A [personal access token](https://help.github.com/articles/creating-a-personal-access-token-for-the-command-line/) 
+      that you will use to make API requests to GitHub.
+    - Ensure that you grant `read/write` permission in the repo for that personal access token.
 
    1. Follow the GitHub instructions to
-      [create a personal access token](https://help.github.com/articles/creating-a-personal-access-token-for-the-command-line/).
-      Ensure to grant the `repo` permission to give `read/write` access to the
-      personal access token.
+    - A webhook secret that you will use to validate requests.
+      
    1. Base64 encode the access token:
 
       ```shell
@@ -50,6 +60,7 @@ webhook.
 
    1. Copy the encoded access token into `github-secret.yaml` next to
       `personalAccessToken:`.
+      
    1. Create a webhook secert value unique to this sample, base64 encode it, and
       copy it into `github-secret.yaml` next to `webhookSecret:`:
 
@@ -74,51 +85,75 @@ webhook.
      name: gitwebhook
      namespace: default
    spec:
-     - containers:
-         # Replace {DOCKER_HUB_USERNAME} with your actual docker hub username
-         image: docker.io/{DOCKER_HUB_USERNAME}/gitwebhook-go
-         env:
-           - name: SECRET_TOKEN
+     template:
+       spec:
+         containers:
+         - # Replace {DOCKER_HUB_USERNAME} with your actual docker hub username
+           image: docker.io/{DOCKER_HUB_USERNAME}/gitwebhook-go:latest
+           env:
+           - name: GITHUB_PERSONAL_TOKEN
              valueFrom:
                secretKeyRef:
                  name: githubsecret
-                 key: secretToken
-           - name: ACCESS_TOKEN
+                 key: personalAccessToken
+           - name: WEBHOOK_SECRET
              valueFrom:
                secretKeyRef:
                  name: githubsecret
-                 key: accessToken
+                 key: webhookSecret
    ```
 
 1. Use `kubectl` to apply the `service.yaml` file.
 
    ```shell
    $ kubectl apply --filename service.yaml
+   ```
+    
+   Response:
+    
+   ```shell
    service "gitwebhook" created
    ```
 
-1. Finally, once the service is running, create the webhook from your GitHub
-   repo to the URL for this service. For this to work properly you will need to
-   [configure a custom domain](../../using-a-custom-domain.md) and
-   [assign a static IP address](../../gke-assigning-static-ip-address.md).
+1. Create a webhook in your GitHub repo using the URL for your `gitwebhook` service:
 
    1. Retrieve the hostname for this service, using the following command:
 
       ```shell
       $ kubectl get ksvc gitwebhook \
-         --output=custom-columns=NAME:.metadata.name,URL:.status.url
-      NAME          URL
-      gitwebhook    http://gitwebhook.default.example.com
+         --output=custom-columns=NAME:.metadata.name,DOMAIN:.status.domain
+      ```
+       
+      Example response:
+       
+      ```shell
+      NAME                DOMAIN
+      gitwebhook          gitwebhook.default.MYCUSTOMDOMAIN.com
       ```
+       
+      where `MYCUSTOMDOMAIN` is the domain that you set as your
+      [custom domain](../../using-a-custom-domain.md).
+
+   1. Go to the GitHub repository for which you have privileges to create a
+      webhook.
+   
+   1. Click **Settings** > **Webhooks** > **Add webhook** to open the Webhooks
+      page.
+   
+   1. Enter the **Payload URL** as `http://{DOMAIN}`, where `{DOMAIN}` is the
+      address from the `kubectl get ksvc gitwebhook` command. 
+      For example: `http://gitwebhook.default.MYCUSTOMDOMAIN.com`
 
-   1. Browse on GitHub to the repository where you want to create a webhook.
-   1. Click **Settings**, then **Webhooks**, then **Add webhook**.
-   1. Fill in **Payload URL** with the value of URL listed above.
    1. Set the **Content type** to `application/json`.
-   1. Enter the **Secret** value to be the same as the original base used for
-      `webhookSecret` above (the original value, not the base64 encoded value).
-   1. Select **Disable** under SSL Validation, unless you've
-      [enabled SSL](../../using-an-ssl-cert.md).
+   
+   1. Enter your webhook secret in **Secret** using the original base value that
+      you set in `webhookSecret` (not the base64 encoded value). For example:
+      `mygithubwebhooksecret`
+      
+   1. If you did not
+      [enabled TLS certificates](../../using-a-tls-cert.md),
+      click **Disable** under **SSL Validation**.
+      
    1. Click **Add webhook** to create the webhook.
 
 ## Exploring