Allow bringing your own alb listener

.changelog/4453.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+plugin/aws-ecs: Fix bringing your own alb listener to ecs deployments.
+```

builtin/aws/ecs/platform.go

@@ -395,7 +395,18 @@ func (p *Platform) Deploy(
 	result.TargetGroupArn = tgState.Arn
 
 	albState := rm.Resource("application load balancer").State().(*Resource_Alb)
-	result.LoadBalancerArn = albState.Arn
+	albListenerState := rm.Resource("alb listener").State().(*Resource_Alb_Listener)
+	if albState != nil && albState.Arn != "" {
+		result.LbReference = &Deployment_LoadBalancerArn{
+			LoadBalancerArn: albState.Arn,
+		}
+	} else if albListenerState != nil && albListenerState.Arn != "" {
+		result.LbReference = &Deployment_ListenerArn{
+			ListenerArn: albListenerState.Arn,
+		}
+	} else {
+		return nil, status.Errorf(codes.FailedPrecondition, "missing an alb and an alb listener - one must be set")
+	}
 
 	cState := rm.Resource("cluster").State().(*Resource_Cluster)
 	result.Cluster = cState.Name
@@ -1720,7 +1731,6 @@ func (p *Platform) resourceAlbCreate(
 	}
 	state.Arn = *lb.LoadBalancerArn
 
-	state.Arn = *lb.LoadBalancerArn
 	state.DnsName = *lb.DNSName
 	state.CanonicalHostedZoneId = *lb.CanonicalHostedZoneId
 
@@ -2514,22 +2524,29 @@ func (p *Platform) loadResourceManagerState(
 		listenerResource.Managed = false
 		log.Debug("Using existing listener", "arn", listenerResource.Arn)
 	} else {
+		var loadBalancerArn string
+		if albRef, ok := deployment.LbReference.(*Deployment_LoadBalancerArn); ok {
+			loadBalancerArn = albRef.LoadBalancerArn
+		} else {
+			return status.Errorf(codes.FailedPrecondition, "cannot restore state to release this old deployment - expecting deployment to have an ALB reference, instead got %T. Please deploy again.", deployment.LbReference)
+		}
+
 		listenerResource.Managed = true
-		s.Update("Describing load balancer %s", deployment.LoadBalancerArn)
+		s.Update("Describing load balancer %s", loadBalancerArn)
 		sess, err := p.getSession(log)
 		if err != nil {
 			return status.Errorf(codes.Internal, "failed to get aws session: %s", err)
 		}
 		elbsrv := elbv2.New(sess)
 
 		listeners, err := elbsrv.DescribeListenersWithContext(ctx, &elbv2.DescribeListenersInput{
-			LoadBalancerArn: &deployment.LoadBalancerArn,
+			LoadBalancerArn: &loadBalancerArn,
 		})
 		if err != nil {
-			return status.Errorf(codes.Internal, "failed to describe listeners for ALB %q: %s", deployment.LoadBalancerArn, err)
+			return status.Errorf(codes.Internal, "failed to describe listeners for ALB %q: %s", loadBalancerArn, err)
 		}
 		if len(listeners.Listeners) == 0 {
-			s.Update("No listeners found for ALB %q", deployment.LoadBalancerArn)
+			s.Update("No listeners found for ALB %q", loadBalancerArn)
 		} else {
 			listenerResource.Arn = *listeners.Listeners[0].ListenerArn
 			s.Update("Found existing listener (ARN: %q)", listenerResource.Arn)

builtin/aws/ecs/plugin.proto

@@ -11,7 +11,14 @@ message Deployment {
   string task_arn = 2;
   string service_arn = 3;
   string target_group_arn = 4;
-  string load_balancer_arn = 5;
+
+  // Reference to the load balancer. Either the LB itself (if we created it),
+  // or the lb listener if the user specified it.
+  oneof lb_reference {
+    string load_balancer_arn = 5;
+    string listener_arn = 8;
+  }
+
   string cluster = 6;
   opaqueany.Any resource_state = 7;
 }

builtin/aws/ecs/releaser.go

@@ -7,6 +7,8 @@ import (
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/service/elbv2"
 	"github.com/hashicorp/go-hclog"
+	"github.com/pkg/errors"
+
 	"github.com/hashicorp/waypoint-plugin-sdk/component"
 	"github.com/hashicorp/waypoint-plugin-sdk/docs"
 	"github.com/hashicorp/waypoint-plugin-sdk/terminal"
@@ -37,8 +39,9 @@ func (r *Releaser) Release(
 	ui terminal.UI,
 	target *Deployment,
 ) (*Release, error) {
-	if target.LoadBalancerArn == "" && target.TargetGroupArn == "" {
-		log.Info("No load-balancer configured")
+
+	if target.TargetGroupArn == "" {
+		log.Info("No target group configured, skipping release")
 		return &Release{}, nil
 	}
 
@@ -51,43 +54,119 @@ func (r *Releaser) Release(
 	}
 	elbsrv := elbv2.New(sess)
 
-	dlb, err := elbsrv.DescribeLoadBalancers(&elbv2.DescribeLoadBalancersInput{
-		LoadBalancerArns: []*string{&target.LoadBalancerArn},
-	})
-	if err != nil {
-		return nil, err
-	}
-
-	var lb *elbv2.LoadBalancer
-
-	if len(dlb.LoadBalancers) == 0 {
-		return nil, fmt.Errorf("No load balancers returned by DescribeLoadBalancers")
-	}
-
-	lb = dlb.LoadBalancers[0]
-
-	listeners, err := elbsrv.DescribeListeners(&elbv2.DescribeListenersInput{
-		LoadBalancerArn: lb.LoadBalancerArn,
-	})
-	if err != nil {
-		return nil, err
+	var hostname string
+	if r.p.config.ALB != nil && r.p.config.ALB.FQDN != "" {
+		hostname = r.p.config.ALB.FQDN
 	}
 
-	var listener *elbv2.Listener
-
 	tgs := []*elbv2.TargetGroupTuple{
 		{
 			TargetGroupArn: &target.TargetGroupArn,
 			Weight:         aws.Int64(100),
 		},
 	}
 
-	log.Debug("configuring weight 100 for target group", "arn", target.TargetGroupArn)
+	// existingListener, if discovered, will be modified to introduce the new target group.
+	var existingListener *elbv2.Listener
+	var lbArn string
+
+	switch lbRef := target.LbReference.(type) {
+	case *Deployment_LoadBalancerArn:
+		// We have a load balancer. Either discover the existing listener, or create a new one.
+		lbArn = lbRef.LoadBalancerArn
+
+		dlb, err := elbsrv.DescribeLoadBalancers(&elbv2.DescribeLoadBalancersInput{
+			LoadBalancerArns: []*string{&lbRef.LoadBalancerArn},
+		})
+		if err != nil {
+			return nil, errors.Wrapf(err, "failed to describe load balancer %q", lbRef.LoadBalancerArn)
+		}
+
+		var lb *elbv2.LoadBalancer
+
+		if len(dlb.LoadBalancers) == 0 {
+			return nil, fmt.Errorf("no load balancers returned by DescribeLoadBalancers")
+		}
 
-	if len(listeners.Listeners) > 0 {
-		listener = listeners.Listeners[0]
+		lb = dlb.LoadBalancers[0]
 
-		def := listener.DefaultActions
+		// Now that we have the LB, set the hostname if necessary
+		if hostname == "" {
+			hostname = *lb.DNSName
+		}
+
+		listeners, err := elbsrv.DescribeListeners(&elbv2.DescribeListenersInput{
+			LoadBalancerArn: lb.LoadBalancerArn,
+		})
+		if err != nil {
+			return nil, errors.Wrapf(err, "failed to describe listener for lb %q", lb.LoadBalancerArn)
+		}
+
+		if len(listeners.Listeners) > 0 {
+			if len(listeners.Listeners) > 1 {
+				log.Warn("ALB has multiple listeners - only modifying the first listaner and ignoring all others")
+			}
+			existingListener = listeners.Listeners[0]
+		} else {
+			log.Info("load-balancer defined", "dns-name", *lb.DNSName)
+
+			_, err := elbsrv.CreateListener(&elbv2.CreateListenerInput{
+				LoadBalancerArn: lb.LoadBalancerArn,
+				Port:            aws.Int64(80),
+				Protocol:        aws.String("HTTP"),
+				DefaultActions: []*elbv2.Action{
+					{
+						ForwardConfig: &elbv2.ForwardActionConfig{
+							TargetGroups: tgs,
+						},
+						Type: aws.String("forward"),
+					},
+				},
+			})
+
+			if err != nil {
+				return nil, errors.Wrapf(err, "failed to create listener")
+			}
+
+			// Do not set existingListener
+		}
+
+	case *Deployment_ListenerArn:
+		lo, err := elbsrv.DescribeListeners(&elbv2.DescribeListenersInput{
+			ListenerArns: []*string{&lbRef.ListenerArn},
+		})
+		if err != nil {
+			return nil, errors.Wrapf(err, "failed to describe listener %q", lbRef.ListenerArn)
+		}
+		if len(lo.Listeners) == 0 {
+			return nil, errors.Errorf("listener %q not found", lbRef.ListenerArn)
+		}
+		existingListener = lo.Listeners[0]
+		lbArn = *existingListener.LoadBalancerArn
+
+		if hostname == "" {
+			// We need to get the hostname from the existing alb
+
+			dlb, err := elbsrv.DescribeLoadBalancers(&elbv2.DescribeLoadBalancersInput{
+				LoadBalancerArns: []*string{existingListener.LoadBalancerArn},
+			})
+			if err != nil {
+				return nil, errors.Wrapf(err, "failed to describe load balancer for listener %q", *existingListener.LoadBalancerArn)
+			}
+
+			if len(dlb.LoadBalancers) == 0 {
+				return nil, fmt.Errorf("no load balancers returned by DescribeLoadBalancers")
+			}
+
+			hostname = *dlb.LoadBalancers[0].DNSName
+		}
+
+	}
+
+	if existingListener != nil {
+		log.Debug("configuring weight 100 for target group", "arn", target.TargetGroupArn)
+
+		def := existingListener.DefaultActions
 
 		if len(def) > 0 && def[0].ForwardConfig != nil {
 			for _, tg := range def[0].ForwardConfig.TargetGroups {
@@ -104,9 +183,9 @@ func (r *Releaser) Release(
 
 		log.Debug("modifying load balancer", "tgs", len(tgs))
 		_, err = elbsrv.ModifyListener(&elbv2.ModifyListenerInput{
-			ListenerArn: listener.ListenerArn,
-			Port:        listener.Port,
-			Protocol:    listener.Protocol,
+			ListenerArn: existingListener.ListenerArn,
+			Port:        existingListener.Port,
+			Protocol:    existingListener.Protocol,
 			DefaultActions: []*elbv2.Action{
 				{
 					ForwardConfig: &elbv2.ForwardActionConfig{
@@ -117,41 +196,13 @@ func (r *Releaser) Release(
 			},
 		})
 		if err != nil {
-			return nil, err
+			return nil, errors.Wrapf(err, "failed to modify listener %q to introduce new target group", existingListener.ListenerArn)
 		}
-	} else {
-		log.Info("load-balancer defined", "dns-name", *lb.DNSName)
-
-		lo, err := elbsrv.CreateListener(&elbv2.CreateListenerInput{
-			LoadBalancerArn: lb.LoadBalancerArn,
-			Port:            aws.Int64(80),
-			Protocol:        aws.String("HTTP"),
-			DefaultActions: []*elbv2.Action{
-				{
-					ForwardConfig: &elbv2.ForwardActionConfig{
-						TargetGroups: tgs,
-					},
-					Type: aws.String("forward"),
-				},
-			},
-		})
-
-		if err != nil {
-			return nil, err
-		}
-
-		listener = lo.Listeners[0]
-	}
-
-	hostname := *lb.DNSName
-
-	if r.p.config.ALB != nil && r.p.config.ALB.FQDN != "" {
-		hostname = r.p.config.ALB.FQDN
 	}
 
 	return &Release{
 		Url:             "http://" + hostname,
-		LoadBalancerArn: *lb.LoadBalancerArn,
+		LoadBalancerArn: lbArn,
 	}, nil
 }
 

embedJson/gen/platform-aws-ecs.json

@@ -334,8 +334,8 @@
          "SubFields": null
       },
       {
-         "Field": "load_balancer_arn",
-         "Type": "string",
+         "Field": "lb_reference",
+         "Type": "ecs.isDeployment_LbReference",
          "Synopsis": "",
          "Summary": "",
          "Optional": false,

website/content/partials/components/platform-aws-ecs.mdx

@@ -387,9 +387,9 @@ Output attributes can be used in your `waypoint.hcl` as [variables](/waypoint/do
 
 - Type: **string**
 
-#### load_balancer_arn
+#### lb_reference
 
-- Type: **string**
+- Type: **ecs.isDeployment_LbReference**
 
 #### resource_state