Red Hat OpenShift Developer II: Building and Deploying Cloud-native Applications

Instructions

1. Log in to OpenShift and create a project to host the image stream for the Nginx container image.

   1. Log in to OpenShift using the developer user account.

      [student@workstation ~]$ oc login -u developer -p developer \
      https://api.ocp4.example.com:6443
      Login successful.
      ...output omitted...

   2. Create a project to host the image streams that are potentially shared among multiple projects.

      [student@workstation ~]$ oc new-project images-streams-common
      Now using project "images-streams-common" on server "registry.ocp4.example.com:8443".
      ...output omitted...

2. Create an image stream that points to the Nginx image from the external registry.

   1. Verify that the redhattraining/hello-world-nginx image from the registry has a tag called latest.

      [student@workstation ~]$ skopeo login registry.ocp4.example.com:8443 \
      -u developer -p developer
      Login Succeeded!

      [student@workstation ~]$ skopeo inspect \
      docker://registry.ocp4.example.com:8443/redhattraining/hello-world-nginx
      {
          "Name": "registry.ocp4.example.com:8443/redhattraining/hello-world-nginx",
          "Digest": "sha256:...output omitted..."
          "RepoTags": [
              "v1.0",
              "latest"
          ],
      ...output omitted...
      }

   2. Create the hello-world image stream that points to the redhattraining/hello-world-nginx container image from the registry.

      [student@workstation ~]$ oc import-image hello-world --confirm \
      --from registry.ocp4.example.com:8443/redhattraining/hello-world-nginx
      imagestream.image.openshift.io/hello-world imported
      
      Name:           hello-world
      Namespace:      images-streams-common
      ...output omitted...
      Unique Images:  1
      Tags:           1
      
      latest
        tagged from registry.ocp4.example.com:8443/redhattraining/hello-world-nginx
      ...output omitted...

   3. Verify that the hello-world:latest image stream tag is created.

      [student@workstation ~]$ oc get istag
      NAME                 IMAGE REF ...output omitted...
      hello-world:latest   registry.ocp4.example.com:8443/redhattraining/hello-world-nginx...output omitted...

   4. Verify that the image stream and its tag contain metadata about the Nginx container image.

      [student@workstation ~]$ oc describe is hello-world
      Name:          hello-world
      Namespace:     images-streams-common
      ...output omitted...
      Tags:          1
      
      latest
        tagged from registry.ocp4.example.com:8443/redhattraining/hello-world-nginx 
      
        * registry.ocp4.example.com:8443/redhattraining/hello-world-nginx@sha256:4f4f...acc1
            2 minutes ago
      
      ...output omitted...

      	The image stream tag hello-world:latest references an image from the classroom Quay instance.
      	The asterisk (*) indicates that the latest image stream tag references only the particular image with the given SHA-256 identifier.

3. Create a new project and deploy an application using the hello-world image stream from the images-streams-common project.

   1. Create a project to host the test application.

      [student@workstation ~]$ oc new-project images-streams-app
      Now using project "images-streams-app" on server "registry.ocp4.example.com:8443".
      ...output omitted...

   2. Deploy an application from the image stream.

      [student@workstation ~]$ oc new-app --name hello \
      -i images-streams-common/hello-world
      --> Found image ...output omitted...
      ...output omitted...
      --> Creating resources ...
          deployment.apps "hello" created
          service "hello" created
      --> Success
      ...output omitted...

   3. Wait until the application pod is ready and running.

      [student@workstation ~]$ oc get pod
      NAME                     READY   STATUS    RESTARTS   AGE
      hello-6599bb7b9c-zk58m   1/1     Running   0          40s

   4. Create a route to expose the application.

      [student@workstation ~]$ oc expose svc hello
      route.route.openshift.io/hello exposed

4. Verify that the application is exposed and works.

   1. Get the host name of the route.

      [student@workstation ~]$ oc get route
      NAME    HOST/PORT ...output omitted...
      hello   hello-images-streams-app.apps.ocp4.example.com ...output omitted...

   2. Test the application using the curl command and the host name from the previous step.

      [student@workstation ~]$ curl \
      http://hello-images-streams-app.apps.ocp4.example.com
      <html>
        <body>
          <h1>Hello, world from nginx!</h1>
        </body>
      </html>