feat: add pagination to MachinePool list api calls (#100)

Since it is possible for a MachinePool to be quite large we need to
make sure we iterate through all pages of possible machine pool
instances.

We have another ticket to make sure all other list calls are also
paginated.

Author: joekr

cloud/scope/machine_pool.go

@@ -165,12 +165,26 @@ func (m *MachinePoolScope) ListMachinePoolInstances(ctx context.Context) ([]core
 		CompartmentId:  common.String(m.OCICluster.Spec.CompartmentId),
 		InstancePoolId: common.String(poolOid),
 	}
-	resp, err := m.ComputeManagementClient.ListInstancePoolInstances(ctx, req)
-	if err != nil {
-		return nil, err
+
+	var instanceSummaries []core.InstanceSummary
+	listPoolInstances := func(ctx context.Context, request core.ListInstancePoolInstancesRequest) (core.ListInstancePoolInstancesResponse, error) {
+		return m.ComputeManagementClient.ListInstancePoolInstances(ctx, request)
 	}
+	for resp, err := listPoolInstances(ctx, req); ; resp, err = listPoolInstances(ctx, req) {
+		if err != nil {
+			return nil, err
+		}
+
+		instanceSummaries = append(instanceSummaries, resp.Items...)
 
-	return resp.Items, nil
+		if resp.OpcNextPage == nil {
+			break
+		} else {
+			req.Page = resp.OpcNextPage
+		}
+	}
+
+	return instanceSummaries, nil
 }
 
 // SetListandSetMachinePoolInstances retrieves a machine pools instances and sets them in the ProviderIDList
@@ -412,6 +426,31 @@ func (m *MachinePoolScope) ReconcileInstanceConfiguration(ctx context.Context) e
 	return nil
 }
 
+// ListInstancePoolSummaries list the core.InstancePoolSummary for the given core.ListInstancePoolsRequest
+func (m *MachinePoolScope) ListInstancePoolSummaries(ctx context.Context, req core.ListInstancePoolsRequest) ([]core.InstancePoolSummary, error) {
+	listInstancePools := func(ctx context.Context, request core.ListInstancePoolsRequest) (core.ListInstancePoolsResponse, error) {
+		return m.ComputeManagementClient.ListInstancePools(ctx, request)
+	}
+
+	var instancePoolSummaries []core.InstancePoolSummary
+	for resp, err := listInstancePools(ctx, req); ; resp, err = listInstancePools(ctx, req) {
+		if err != nil {
+			return instancePoolSummaries, errors.Wrapf(err, "failed to query OCIMachinePool by name")
+		}
+
+		instancePoolSummaries = append(instancePoolSummaries, resp.Items...)
+
+		if resp.OpcNextPage == nil {
+			// no more pages
+			break
+		} else {
+			req.Page = resp.OpcNextPage
+		}
+	}
+
+	return instancePoolSummaries, nil
+}
+
 // FindInstancePool attempts to find the instance pool by name and checks to make sure
 // the instance pool was created by the cluster before returning the correct pool
 func (m *MachinePoolScope) FindInstancePool(ctx context.Context) (*core.InstancePool, error) {
@@ -422,18 +461,14 @@ func (m *MachinePoolScope) FindInstancePool(ctx context.Context) (*core.Instance
 		CompartmentId: common.String(m.OCICluster.Spec.CompartmentId),
 		DisplayName:   common.String(m.OCIMachinePool.GetName()),
 	}
-	respList, err := m.ComputeManagementClient.ListInstancePools(ctx, reqList)
-	if err != nil {
-		return nil, errors.Wrapf(err, "failed to query OCIMachinePool by name")
-	}
 
-	if len(respList.Items) <= 0 {
-		m.Info("No machine pool found", "machinepool-name", m.OCIMachinePool.GetName())
-		return nil, nil
+	instancePoolSummaries, err := m.ListInstancePoolSummaries(ctx, reqList)
+	if err != nil {
+		return nil, err
 	}
 
 	var instancePoolSummary *core.InstancePoolSummary
-	for _, i := range respList.Items {
+	for _, i := range instancePoolSummaries {
 		if m.IsResourceCreatedByClusterAPI(i.FreeformTags) {
 			instancePoolSummary = &i
 			break