Issue 82: Ability to scale Pravega Controller

[adrianmo]

Change log description

This PR adds the ability to scale the number of Controller replicas. It has been implemented in the pkg/pravega/sync.go file, in the same way as other components are scaled (Segmentstore, Bookkeeper), i.e., the code obtains the desired number of replicas from the updated manifest and makes sure the Controller Deployment object is in sync.

Purpose of the change

• Fix Pravega-controller pods failed to scale up  #82

How to test the change

Checkout the repository (master branch is fine, no need to checkout this branch).

Edit the operator image used in the deploy/operator.yaml file to use the adrianmo/pravega-operator:issue-82-1 image, which contains the changes in this PR.

Follow the instructions in the README file to install the operator, deploy the operator, and create a Pravega cluster.

By default, there will only be one Controller replica.

$ kubectl get all -l pravega_cluster=pravega
NAME                                             READY     STATUS    RESTARTS   AGE                                                                            
pod/pravega-bookie-0                             1/1       Running   0          28m                                                                            
pod/pravega-bookie-1                             1/1       Running   0          28m                                                                            
pod/pravega-bookie-2                             1/1       Running   0          28m                                                                            
pod/pravega-pravega-controller-c9875fc6d-l7prt   1/1       Running   0          28m                                                                            
pod/pravega-segmentstore-0                       1/1       Running   1          28m                                                                            
pod/pravega-segmentstore-1                       1/1       Running   1          28m                                                                            
pod/pravega-segmentstore-2                       1/1       Running   1          28m                                                                            

NAME                                 TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)              AGE                                                        
service/pravega-bookie-headless      ClusterIP   None            <none>        3181/TCP             28m                                                        
service/pravega-pravega-controller   ClusterIP   10.71.254.167   <none>        10080/TCP,9090/TCP   28m                                                        

NAME                                               DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE                                                            
deployment.extensions/pravega-pravega-controller   1         1         1            1           28m                                                            

NAME                                                         DESIRED   CURRENT   READY     AGE                                                                 
replicaset.extensions/pravega-pravega-controller-c9875fc6d   1         1         1         28m                                                                 

NAME                                         DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE                                                                  
deployment.apps/pravega-pravega-controller   1         1         1            1           28m                                                                  

NAME                                                   DESIRED   CURRENT   READY     AGE                                                                       
replicaset.apps/pravega-pravega-controller-c9875fc6d   1         1         1         28m                                                                       

NAME                                    DESIRED   CURRENT   AGE
statefulset.apps/pravega-bookie         3         3         28m
statefulset.apps/pravega-segmentstore   3         3         28m

To scale the number of Controller replicas, edit the PravegaCluster resource and update the controllerReplicas field.

$ kubectl edit PravegaCluster pravega

Verify that the number of Controller pods matches with the number of replicas.

$ kubectl get po -l pravega_cluster=pravega
NAME                                         READY     STATUS    RESTARTS   AGE
pravega-bookie-0                             1/1       Running   0          28m                                                                            
pravega-bookie-1                             1/1       Running   0          28m                                                                            
pravega-bookie-2                             1/1       Running   0          28m                                                                            
pravega-pravega-controller-c9875fc6d-l7prt   1/1       Running   0          28m                                                                            
pravega-pravega-controller-c9875fc6d-nsg5v   1/1       Running   0          28m                                                                            
pravega-segmentstore-0                       1/1       Running   1          28m                                                                            
pravega-segmentstore-1                       1/1       Running   1          28m                                                                            
pravega-segmentstore-2                       1/1       Running   1          28m 

Run a Pravega sample as explained here to verify that Pravega works as expected.

---

Signed-off-by: Adrian Moreno adrian@morenomartinez.com

[adrianmo]

@shrids please take a look at this change and let me know if it unblocks your work on pravega/pravega#3135

[adrianmo]

Operator: Ability to scale Pravega Controller

[shrids]

+1

[fpj]

+1

[deenav]

I have tested and verified that Pravega Controller scaling works fine with this fix.