Fix null canary object (#3435)

* Do not send null canary object if no steps have been specified

Author: Samze

actor/v7pushaction/create_deployment_for_push_plan.go

@@ -19,7 +19,7 @@ func (actor Actor) CreateDeploymentForApplication(pushPlan PushPlan, eventStream
 	}
 
 	if len(pushPlan.InstanceSteps) > 0 {
-		dep.Options.CanaryDeploymentOptions = resources.CanaryDeploymentOptions{Steps: []resources.CanaryStep{}}
+		dep.Options.CanaryDeploymentOptions = &resources.CanaryDeploymentOptions{Steps: []resources.CanaryStep{}}
 		for _, w := range pushPlan.InstanceSteps {
 			dep.Options.CanaryDeploymentOptions.Steps = append(dep.Options.CanaryDeploymentOptions.Steps, resources.CanaryStep{InstanceWeight: w})
 		}

actor/v7pushaction/create_deployment_for_push_plan_test.go

@@ -175,7 +175,7 @@ var _ = Describe("CreateDeploymentForApplication()", func() {
 				Expect(dep).To(Equal(resources.Deployment{
 					Strategy: "canary",
 					Options: resources.DeploymentOpts{
-						CanaryDeploymentOptions: resources.CanaryDeploymentOptions{
+						CanaryDeploymentOptions: &resources.CanaryDeploymentOptions{
 							Steps: []resources.CanaryStep{
 								{InstanceWeight: 1},
 								{InstanceWeight: 2},

api/cloudcontroller/ccv3/deployment_test.go

@@ -251,7 +251,7 @@ var _ = Describe("Deployment", func() {
 			dep.Strategy = constant.DeploymentStrategyCanary
 			dep.RevisionGUID = revisionGUID
 			dep.Relationships = resources.Relationships{constant.RelationshipTypeApplication: resources.Relationship{GUID: "some-app-guid"}}
-			dep.Options.CanaryDeploymentOptions = resources.CanaryDeploymentOptions{Steps: []resources.CanaryStep{{InstanceWeight: 1}, {InstanceWeight: 2}}}
+			dep.Options.CanaryDeploymentOptions = &resources.CanaryDeploymentOptions{Steps: []resources.CanaryStep{{InstanceWeight: 1}, {InstanceWeight: 2}}}
 			deploymentGUID, warnings, executeErr = client.CreateApplicationDeployment(dep)
 		})
 

resources/deployment_resource.go

@@ -24,12 +24,12 @@ type Deployment struct {
 }
 
 type DeploymentOpts struct {
-	MaxInFlight             int                     `json:"max_in_flight,omitempty"`
-	CanaryDeploymentOptions CanaryDeploymentOptions `json:"canary,omitempty"`
+	MaxInFlight             int                      `json:"max_in_flight,omitempty"`
+	CanaryDeploymentOptions *CanaryDeploymentOptions `json:"canary,omitempty"`
 }
 
 func (d DeploymentOpts) IsEmpty() bool {
-	return d.MaxInFlight == 0 && len(d.CanaryDeploymentOptions.Steps) == 0
+	return d.MaxInFlight == 0 && (d.CanaryDeploymentOptions == nil || len(d.CanaryDeploymentOptions.Steps) == 0)
 }
 
 type CanaryDeploymentOptions struct {