Add top-level ELB Attachment resource

Add an aws_elb_attachment resource so that the attment of instances to
an ELB can be managed separately from an aws_elb and prevent dependency
cycles.

builtin/providers/aws/provider.go

@@ -176,6 +176,7 @@ func Provider() terraform.ResourceProvider {
 			"aws_elastic_beanstalk_environment":            resourceAwsElasticBeanstalkEnvironment(),
 			"aws_elasticsearch_domain":                     resourceAwsElasticSearchDomain(),
 			"aws_elb":                                      resourceAwsElb(),
+			"aws_elb_attachment":                           resourceAwsElbAttachment(),
 			"aws_flow_log":                                 resourceAwsFlowLog(),
 			"aws_glacier_vault":                            resourceAwsGlacierVault(),
 			"aws_iam_access_key":                           resourceAwsIamAccessKey(),

builtin/providers/aws/resource_aws_elb_attachment.go

@@ -0,0 +1,142 @@
+package aws
+
+import (
+	"fmt"
+	"log"
+
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/service/elb"
+	"github.com/hashicorp/terraform/helper/resource"
+	"github.com/hashicorp/terraform/helper/schema"
+)
+
+func resourceAwsElbAttachment() *schema.Resource {
+	return &schema.Resource{
+		Create: resourceAwsElbAttachmentCreate,
+		Read:   resourceAwsElbAttachmentRead,
+		Update: resourceAwsElbAttachmentUpdate,
+		Delete: resourceAwsElbAttachmentDelete,
+		Importer: &schema.ResourceImporter{
+			State: schema.ImportStatePassthrough,
+		},
+
+		Schema: map[string]*schema.Schema{
+			"elb": &schema.Schema{
+				Type:     schema.TypeString,
+				Required: true,
+			},
+
+			"instances": &schema.Schema{
+				Type:     schema.TypeSet,
+				Elem:     &schema.Schema{Type: schema.TypeString},
+				Set:      schema.HashString,
+				Required: true,
+			},
+		},
+	}
+}
+
+func resourceAwsElbAttachmentCreate(d *schema.ResourceData, meta interface{}) error {
+	elbconn := meta.(*AWSClient).elbconn
+	elbName := d.Get("elb").(string)
+
+	instances := expandInstanceString(d.Get("instances").(*schema.Set).List())
+
+	registerInstancesOpts := elb.RegisterInstancesWithLoadBalancerInput{
+		LoadBalancerName: aws.String(elbName),
+		Instances:        instances,
+	}
+
+	_, err := elbconn.RegisterInstancesWithLoadBalancer(&registerInstancesOpts)
+	if err != nil {
+		return fmt.Errorf("Failure registering instances with ELB: %s", err)
+	}
+
+	d.SetId(resource.PrefixedUniqueId(fmt.Sprintf("%s-", elbName)))
+
+	return nil
+}
+
+func resourceAwsElbAttachmentRead(d *schema.ResourceData, meta interface{}) error {
+	elbconn := meta.(*AWSClient).elbconn
+	elbName := d.Get("elb").(string)
+
+	// Retrieve the ELB properties to get a list of attachments
+	describeElbOpts := &elb.DescribeLoadBalancersInput{
+		LoadBalancerNames: []*string{aws.String(elbName)},
+	}
+
+	describeResp, err := elbconn.DescribeLoadBalancers(describeElbOpts)
+	if err != nil {
+		return fmt.Errorf("Error retrieving ELB: %s", err)
+	}
+	if len(describeResp.LoadBalancerDescriptions) != 1 {
+		return fmt.Errorf("Unable to find ELB: %#v", describeResp.LoadBalancerDescriptions)
+	}
+
+	lb := describeResp.LoadBalancerDescriptions[0]
+
+	d.Set("instances", flattenInstances(lb.Instances))
+
+	return nil
+}
+
+func resourceAwsElbAttachmentUpdate(d *schema.ResourceData, meta interface{}) error {
+	elbconn := meta.(*AWSClient).elbconn
+	elbName := d.Get("elb").(string)
+
+	if d.HasChange("instances") {
+		o, n := d.GetChange("instances")
+		os := o.(*schema.Set)
+		ns := n.(*schema.Set)
+		remove := expandInstanceString(os.Difference(ns).List())
+		add := expandInstanceString(ns.Difference(os).List())
+
+		if len(add) > 0 {
+			registerInstancesOpts := elb.RegisterInstancesWithLoadBalancerInput{
+				LoadBalancerName: aws.String(elbName),
+				Instances:        add,
+			}
+
+			_, err := elbconn.RegisterInstancesWithLoadBalancer(&registerInstancesOpts)
+			if err != nil {
+				return fmt.Errorf("Failure registering instances with ELB: %s", err)
+			}
+		}
+		if len(remove) > 0 {
+			deRegisterInstancesOpts := elb.DeregisterInstancesFromLoadBalancerInput{
+				LoadBalancerName: aws.String(elbName),
+				Instances:        remove,
+			}
+
+			_, err := elbconn.DeregisterInstancesFromLoadBalancer(&deRegisterInstancesOpts)
+			if err != nil {
+				return fmt.Errorf("Failure deregistering instances from ELB: %s", err)
+			}
+		}
+	}
+
+	return resourceAwsElbAttachmentRead(d, meta)
+}
+
+func resourceAwsElbAttachmentDelete(d *schema.ResourceData, meta interface{}) error {
+	elbconn := meta.(*AWSClient).elbconn
+	elbName := d.Get("elb").(string)
+
+	instanceSet := d.Get("instances").(*schema.Set)
+	instances := expandInstanceString(instanceSet.List())
+
+	log.Printf("[INFO] Deleting Attachments %s from: %s", instanceSet, elbName)
+
+	deRegisterInstancesOpts := elb.DeregisterInstancesFromLoadBalancerInput{
+		LoadBalancerName: aws.String(elbName),
+		Instances:        instances,
+	}
+
+	_, err := elbconn.DeregisterInstancesFromLoadBalancer(&deRegisterInstancesOpts)
+	if err != nil {
+		return fmt.Errorf("Failure deregistering instances from ELB: %s", err)
+	}
+
+	return nil
+}

builtin/providers/aws/resource_aws_elb_attachment_test.go

@@ -0,0 +1,123 @@
+package aws
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/aws/aws-sdk-go/service/elb"
+	"github.com/hashicorp/terraform/helper/resource"
+	"github.com/hashicorp/terraform/terraform"
+)
+
+func TestAccAWSELBAttachment(t *testing.T) {
+	var conf elb.LoadBalancerDescription
+
+	testCheckInstanceAttached := func(count int) resource.TestCheckFunc {
+		return func(*terraform.State) error {
+			if len(conf.Instances) != count {
+				return fmt.Errorf("instance count does not match")
+			}
+			return nil
+		}
+	}
+
+	resource.Test(t, resource.TestCase{
+		PreCheck:      func() { testAccPreCheck(t) },
+		IDRefreshName: "aws_elb.bar",
+		Providers:     testAccProviders,
+		CheckDestroy:  testAccCheckAWSELBDestroy,
+		Steps: []resource.TestStep{
+			resource.TestStep{
+				Config: testAccAWSELBAttachmentConfig1,
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckAWSELBExists("aws_elb.bar", &conf),
+					testCheckInstanceAttached(1),
+				),
+			},
+
+			resource.TestStep{
+				Config: testAccAWSELBAttachmentConfig2,
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckAWSELBExists("aws_elb.bar", &conf),
+					testCheckInstanceAttached(2),
+				),
+			},
+
+			resource.TestStep{
+				Config: testAccAWSELBAttachmentConfig3,
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckAWSELBExists("aws_elb.bar", &conf),
+					testCheckInstanceAttached(0),
+				),
+			},
+		},
+	})
+
+}
+
+const testAccAWSELBAttachmentConfig1 = `
+resource "aws_elb" "bar" {
+  availability_zones = ["us-west-2a", "us-west-2b", "us-west-2c"]
+
+  listener {
+    instance_port = 8000
+    instance_protocol = "http"
+    lb_port = 80
+    lb_protocol = "http"
+  }
+}
+
+resource "aws_instance" "foo" {
+	# us-west-2
+	ami = "ami-043a5034"
+	instance_type = "t1.micro"
+}
+
+resource "aws_elb_attachment" "app" {
+  elb      = "${aws_elb.bar.id}"
+  instances = ["${aws_instance.foo.id}"]
+}
+`
+
+const testAccAWSELBAttachmentConfig2 = `
+resource "aws_elb" "bar" {
+  availability_zones = ["us-west-2a", "us-west-2b", "us-west-2c"]
+
+  listener {
+    instance_port = 8000
+    instance_protocol = "http"
+    lb_port = 80
+    lb_protocol = "http"
+  }
+}
+
+resource "aws_instance" "foo" {
+	# us-west-2
+	ami = "ami-043a5034"
+	instance_type = "t1.micro"
+}
+
+resource "aws_instance" "foo2" {
+	# us-west-2
+	ami = "ami-043a5034"
+	instance_type = "t1.micro"
+}
+
+resource "aws_elb_attachment" "app" {
+  elb      = "${aws_elb.bar.id}"
+  instances = ["${aws_instance.foo.id}", "${aws_instance.foo2.id}"]
+}
+`
+
+const testAccAWSELBAttachmentConfig3 = `
+resource "aws_elb" "bar" {
+  availability_zones = ["us-west-2a", "us-west-2b", "us-west-2c"]
+
+  listener {
+    instance_port = 8000
+    instance_protocol = "http"
+    lb_port = 80
+    lb_protocol = "http"
+  }
+}
+`