Troubleshoot Migration Problems

If you encounter problems migrating your Oracle Application Container Cloud Service application to Oracle Cloud Infrastructure, then you can do troubleshooting during your migration.

Verify the Status of the Kubernetes Resources

If the deployment of your application fails, then you can fetch details of the deployment, pods, and service.

1. Fetch the deployments in your Kubernetes cluster.

   kubectl get deployments

   Example:

   $ kubectl get deployments
   NAME                     DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
   webapp01-deployment      2         2         2            2           16h
   webapp02-deployment      1         1         1            1           2d
   javaeeapp01-deployment   1         1         1            1           1d
   javaeeapp02-deployment   1         1         1            0           1d

   The value under the DESIRED and AVAILABLE columns should be at least 1. If the values is 0, then you have a problem in your deployment.

2. Fetch the services in your Kubernetes cluster.

   kubectl get services

   Example:

   $ kubectl get services
   NAME                  TYPE           CLUSTER-IP      EXTERNAL-IP       PORT(S)         AGE
   webapp01-service      LoadBalancer   10.x.x.x        132.x.x.x         80:43678/TCP    16h
   webapp02-service      LoadBalancer   10.x.x.x        132.x.x.x         443:32628/TCP   2d
   javaeeapp01-service   LoadBalancer   10.96.112.230   10.x.x.x          443:30824/TCP   1d
   javaeeapp02-service   LoadBalancer   10.96.142.94    10.x.x.x          443:30830/TCP   1d

   The value under the TYPE column should be ClusterIP or LoadBalancer according to you application. The value under the EXTERNAL-IP should be a valid IP address. If you have different values, then you have a problem in your service.

3. Fetch the pods in your Kubernetes cluster.

   kubectl get pods

   Example:

   $ kubectl get pods
   NAME                                      READY   STATUS             RESTARTS   AGE
   javaeeapp01-deployment-67fb54b6c4-bdsfh   1/1     Running            0          1d
   javaeeapp02-deployment-79f8f9bff9-42dqk   1/1     Running            0          1d
   webapp01-deployment-7977d9f97b-4d4s9      0/1     Failed             0          16h
   webapp01-deployment-7977d9f97b-7bwqf      1/1     Running            0          16h

   The value under the STATUS column should be Running. If the value is FAILED, then you have a problem in your pod.

4. To fetch more details about a failed resource, run the following command. Provide appropriate values for the <resource-type> and <resource-id-or-name> placeholders.

   kubectl describe <resource-type> <resource-id-or-name>

   Example:

   $ kubectl describe deployment webapp01-deployment
   Name:                   webapp01-deployment
   Namespace:              default
   CreationTimestamp:      Thu, 07 Feb 2019 17:20:03 +0530
   ...
   Pod Template:
     Labels:  app=webapp01-selector
     Containers:
      webapp01:
       Image:      fra.ocir.io/tenancy1/accs/oci_user1/webapp01:latest
       Port:       8080/TCP
       Host Port:  0/TCP
   ...
   Conditions:
     Type           Status  Reason
     ----           ------  ------
     Available      False   MinimumReplicasUnavailable
     Progressing    False   ProgressDeadlineExceeded
   OldReplicaSets:  <none>
   NewReplicaSet:   webapp01-deployment-7977d9f97b (2/2 replicas created)
   Events:          <none>

Delete Resources Created During Migration

Remove the resources created during the migration facilitates quick recovery in the event of migration failure.

1. Delete the Kubernetes service. Provide an appropriate value for <app-name>.

   kubectl delete service <app-name>-service

   Example:

   $ kubectl delete service webapp01-service
   service "webapp01-service" deleted

2. Delete Kubernetes deployment. Provide an appropriate value for <app-name>.

   kubectl delete deployment <app-name>-deployment

   Example:

   $ kubectl delete deployment webapp01-deployment
   service "webapp01-deployment" deleted

3. Delete Kubernetes secret for TLS key and certificate. Provide an appropriate value for <app-name>.

   kubectl delete secret <app-name>-tls-certificate

   Example:

   $ kubectl delete secret webapp01-tls-certificate
   secret "webapp01-tls-certificate" deleted

4. Delete Kubernetes docker secret. Provide an appropriate value for <app-name>.

   kubectl delete secret <app-name>-secret

   Example:

   $ kubectl delete secret webapp01-secret
   secret "webapp01-secret" deleted

5. Delete Kubernetes configuration map for environment variables. Provide an appropriate value for <app-name>.

   kubectl delete configmap <app-name>-config-var-map

   Example:

   $ kubectl delete configmap webapp01-config-var-map
   configmap "webapp01-config-var-map" deleted

After you delete the Kubernetes resources, you can restart the migration process.