Chapter 4. Creating and building an application using the CLI

Procedure

1. To retrieve the created application service, enter the following command:

   $ oc get service

   Example output

   NAME      TYPE       CLUSTER-IP         EXTERNAL-IP    PORT(S)   AGE
   parksmap  ClusterIP  <your-cluster-IP>  <123.456.789>  8080/TCP  8m29s

2. To create a route, enter the following command:

   $ oc create route edge parksmap --service=parksmap

   Example output

   route.route.openshift.io/parksmap created

3. To retrieve the created application route, enter the following command:

   $ oc get route

   Example output

   NAME        HOST/PORT                                                   PATH   SERVICES   PORT       TERMINATION   WILDCARD
   parksmap    parksmap-user-getting-started.apps.cluster.example.com             parksmap   8080-tcp   edge          None

Procedure

1. To list all pods with node names, enter the following command:

   $ oc get pods

   Example output

   NAME                       READY   STATUS    RESTARTS   AGE
   parksmap-5f9579955-6sng8   1/1     Running   0          77s

2. To list all pod details, enter the following command:

   $ oc describe pods

   Example output

   Name:         parksmap-848bd4954b-5pvcc
   Namespace:    user-getting-started
   Priority:     0
   Node:         ci-ln-fr1rt92-72292-4fzf9-worker-a-g9g7c/10.0.128.4
   Start Time:   Sun, 13 Feb 2022 14:14:14 -0500
   Labels:       app=national-parks-app
                 app.kubernetes.io/part-of=national-parks-app
                 component=parksmap
                 deployment=parksmap
                 pod-template-hash=848bd4954b
                 role=frontend
   Annotations:  k8s.v1.cni.cncf.io/network-status:
                   [{
                       "name": "ovn-kubernetes",
                       "interface": "eth0",
                       "ips": [
                           "10.131.0.14"
                       ],
                       "default": true,
                       "dns": {}
                   }]
                 k8s.v1.cni.cncf.io/network-status:
                   [{
                       "name": "ovn-kubernetes",
                       "interface": "eth0",
                       "ips": [
                           "10.131.0.14"
                       ],
                       "default": true,
                       "dns": {}
                   }]
                 openshift.io/generated-by: OpenShiftNewApp
                 openshift.io/scc: restricted
   Status:       Running
   IP:           10.131.0.14
   IPs:
     IP:           10.131.0.14
   Controlled By:  ReplicaSet/parksmap-848bd4954b
   Containers:
     parksmap:
       Container ID:   cri-o://4b2625d4f61861e33cc95ad6d455915ea8ff6b75e17650538cc33c1e3e26aeb8
       Image:          quay.io/openshiftroadshow/parksmap@sha256:89d1e324846cb431df9039e1a7fd0ed2ba0c51aafbae73f2abd70a83d5fa173b
       Image ID:       quay.io/openshiftroadshow/parksmap@sha256:89d1e324846cb431df9039e1a7fd0ed2ba0c51aafbae73f2abd70a83d5fa173b
       Port:           8080/TCP
       Host Port:      0/TCP
       State:          Running
         Started:      Sun, 13 Feb 2022 14:14:25 -0500
       Ready:          True
       Restart Count:  0
       Environment:    <none>
       Mounts:
         /var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-6f844 (ro)
   Conditions:
     Type              Status
     Initialized       True
     Ready             True
     ContainersReady   True
     PodScheduled      True
   Volumes:
     kube-api-access-6f844:
       Type:                    Projected (a volume that contains injected data from multiple sources)
       TokenExpirationSeconds:  3607
       ConfigMapName:           kube-root-ca.crt
       ConfigMapOptional:       <nil>
       DownwardAPI:             true
       ConfigMapName:           openshift-service-ca.crt
       ConfigMapOptional:       <nil>
   QoS Class:                   BestEffort
   Node-Selectors:              <none>
   Tolerations:                 node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
                                node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
   Events:
     Type    Reason          Age   From               Message
     ----    ------          ----  ----               -------
     Normal  Scheduled       46s   default-scheduler  Successfully assigned user-getting-started/parksmap-848bd4954b-5pvcc to ci-ln-fr1rt92-72292-4fzf9-worker-a-g9g7c
     Normal  AddedInterface  44s   multus             Add eth0 [10.131.0.14/23] from ovn-kubernetes
     Normal  Pulling         44s   kubelet            Pulling image "quay.io/openshiftroadshow/parksmap@sha256:89d1e324846cb431df9039e1a7fd0ed2ba0c51aafbae73f2abd70a83d5fa173b"
     Normal  Pulled          35s   kubelet            Successfully pulled image "quay.io/openshiftroadshow/parksmap@sha256:89d1e324846cb431df9039e1a7fd0ed2ba0c51aafbae73f2abd70a83d5fa173b" in 9.49243308s
     Normal  Created         35s   kubelet            Created container parksmap
     Normal  Started         35s   kubelet            Started container parksmap

Verification

1. To ensure that your application scaled properly, enter the following command:

   $ oc get pods

   Example output

   NAME                       READY   STATUS    RESTARTS   AGE
   parksmap-5f9579955-6sng8   1/1     Running   0          7m39s
   parksmap-5f9579955-8tgft   1/1     Running   0          24s

2. To scale your application back down to one pod instance, enter the following command:

   $ oc scale --current-replicas=2 --replicas=1 deployment/parksmap

Procedure

1. To create a secret, enter the following command:

   $ oc create secret generic nationalparks-mongodb-parameters --from-literal=DATABASE_SERVICE_NAME=mongodb-nationalparks --from-literal=MONGODB_USER=mongodb --from-literal=MONGODB_PASSWORD=mongodb --from-literal=MONGODB_DATABASE=mongodb --from-literal=MONGODB_ADMIN_PASSWORD=mongodb

   Example output

   secret/nationalparks-mongodb-parameters created

2. To update the environment variable to attach the mongodb secret to the nationalpartks workload, enter the following command:

   $ oc set env --from=secret/nationalparks-mongodb-parameters deploy/nationalparks

   Example output

   deployment.apps/nationalparks updated

3. To show the status of the nationalparks deployment, enter the following command:

   $ oc rollout status deployment nationalparks

   Example output

   deployment "nationalparks" successfully rolled out

4. To show the status of the mongodb-nationalparks deployment, enter the following command:

   $ oc rollout status deployment mongodb-nationalparks

   Example output

   deployment "nationalparks" successfully rolled out
   deployment "mongodb-nationalparks" successfully rolled out

Procedure

1. To load national parks data, enter the following command:

   $ oc exec $(oc get pods -l component=nationalparks | tail -n 1 | awk '{print $1;}') -- curl -s http://localhost:8080/ws/data/load

   Example output

   "Items inserted in database: 2893"

2. To verify that your data is loaded properly, enter the following command:

   $ oc exec $(oc get pods -l component=nationalparks | tail -n 1 | awk '{print $1;}') -- curl -s http://localhost:8080/ws/data/all

   Example output (trimmed)

   , {"id": "Great Zimbabwe", "latitude": "-20.2674635", "longitude": "30.9337986", "name": "Great Zimbabwe"}]

3. To add labels to the route, enter the following command:

   $ oc label route nationalparks type=parksmap-backend

   Example output

   route.route.openshift.io/nationalparks labeled

4. To retrieve your routes to view your map, enter the following command:

   $ oc get routes

   Example output

   NAME            HOST/PORT                                                      PATH   SERVICES        PORT       TERMINATION   WILDCARD
   nationalparks   nationalparks-user-getting-started.apps.cluster.example.com           nationalparks   8080-tcp   edge          None
   parksmap        parksmap-user-getting-started.apps.cluster.example.com                parksmap        8080-tcp   edge          None

5. Copy and paste the HOST/PORT path you retrieved above into your web browser. Your browser should display a map of the national parks across the world.

   Figure 4.1. National parks across the world