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

Instructions

Use the following as the input data for the required actions:

1. Build the container image in the ~/DO288/labs/images-review directory.

   1. Go to the location of the container that the exercise provides.

      [student@workstation ~]$ cd ~/DO288/labs/images-review

   2. Review the Containerfile contents.

      [student@workstation images-review]$ cat Containerfile
      FROM registry.ocp4.example.com:8443/redhattraining/hello-world-nginx:latest
      
      USER root
      
      RUN sed -i "s/nginx/OpenShift/g" /usr/share/nginx/html/index.html
      
      USER 1001

   3. Log in to the classroom container registry.

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

   4. Build the container image.

      [student@workstation images-review]$ podman build . \
        -t registry.ocp4.example.com:8443/developer/custom-server:1.0.0
      STEP 1/4: FROM registry.ocp4.example.com:8443/redhattraining/hello-world-nginx:latest
      STEP 2/4: USER root
      --> c8bd9df97f6
      STEP 3/4: RUN sed -i "s/nginx/OpenShift/g" /usr/share/nginx/html/index.html
      --> a09383c6d5e
      STEP 4/4: USER 1001
      COMMIT registry.ocp4.example.com:8443/developer/custom-server:1.0.0
      --> afef715ff1d
      Successfully tagged registry.ocp4.example.com:8443/developer/custom-server:1.0.0
      afef715ff1daffe01e1f0a225fbaa089ee28617d23e9ffc4e91f4f6f75c32faa

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2. Push the custom-server image to the classroom private registry.

   1. Push the container image to the internal classroom registry.

      [student@workstation images-review]$ podman push \
        registry.ocp4.example.com:8443/developer/custom-server:1.0.0
      ...output omitted...
      Writing manifest to image destination
      Storing signatures

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3. Create a secret called registry-credentials to access the private registry by using the data that the exercise provides.

   1. Log in to Red Hat OpenShift.

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

   2. Ensure that you are in the images-review project.

      [student@workstation images-review]$ oc project images-review
      Already on project"images-review" on server "https://api.ocp4.example.com:6443".

   3. Create the registry-credentials secret of the docker-registry type that contains the credentials.

      [student@workstation images-review]$ oc create secret docker-registry \
        registry-credentials \
        --docker-server=registry.ocp4.example.com:8443 \
        --docker-username=developer \
        --docker-password=developer \
        --docker-email=developer@example.org
      secret/registry-credentials created

   4. Link the secret to the default service account.

      [student@workstation images-review]$ oc secrets link default \
        registry-credentials --for=pull
      no output expected

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4. Create an image stream for the custom-server:1.0.0 image that you pushed to the classroom registry.

   1. Create the custom-server image stream that points to the container image that you pushed to the registry.

      [student@workstation images-review]$ oc import-image custom-server --confirm \
      --from registry.ocp4.example.com:8443/developer/custom-server:1.0.0
      imagestream.image.openshift.io/custom-server imported
      
      Name:           custom-server
      Namespace:      images-review
      ...output omitted...
      Unique Images:  1
      Tags:           1
      
      latest
        tagged from registry.ocp4.example.com:8443/developer/custom-server:1.0.0
      ...output omitted...

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5. Create an OpenShift application by using the custom-server image stream.

   1. Deploy an application by using the image stream.

      [student@workstation images-review]$ oc new-app --name custom-server \
      -i images-review/custom-server
      --> Found image ...output omitted...
      ...output omitted...
      --> Creating resources ...
          deployment.apps "custom-server" created
          service "custom-server" created
      --> Success
      ...output omitted...

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

      [student@workstation images-review]$ oc get pod
      NAME                     READY   STATUS    RESTARTS   AGE
      custom-server-7d597c89c4-lng8p   1/1     Running   0          30s

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6. Validate that the application works by using the route URL and by verifying that the Hello, world from OpenShift! string shows in the response.

   1. Create a route to expose the application.

      [student@workstation images-review]$ oc expose svc custom-server
      route.route.openshift.io/custom-server exposed

   2. Get the hostname of the route.

      [student@workstation images-review]$ oc get route
      NAME    HOST/PORT ...output omitted...
      custom-server   custom-server-images-review.apps.ocp4.example.com ...output omitted...

   3. Test the application by using the curl command and the hostname from the previous step.

      [student@workstation images-review]$ curl \
        http://custom-server-images-review.apps.ocp4.example.com
      <html>
        <body>
          <h1>Hello, world from OpenShift!</h1>
        </body>
      </html>