provider/aws: avoid ecs cluster name collisions

builtin/providers/aws/data_source_aws_ecs_cluster.go

@@ -50,29 +50,28 @@ func dataSourceAwsEcsCluster() *schema.Resource {
 func dataSourceAwsEcsClusterRead(d *schema.ResourceData, meta interface{}) error {
 	conn := meta.(*AWSClient).ecsconn
 
-	desc, err := conn.DescribeClusters(&ecs.DescribeClustersInput{})
+	desc, err := conn.DescribeClusters(&ecs.DescribeClustersInput{
+		Clusters: []*string{aws.String(d.Get("cluster_name").(string))},
+	})
 
 	if err != nil {
 		return err
 	}
 
-	var c *ecs.Cluster
 	for _, cluster := range desc.Clusters {
-		if aws.StringValue(cluster.ClusterName) == d.Get("cluster_name").(string) {
-			c = cluster
-			break
+		if aws.StringValue(cluster.ClusterName) != d.Get("cluster_name").(string) {
+			continue
 		}
+		d.SetId(aws.StringValue(cluster.ClusterArn))
+		d.Set("status", cluster.Status)
+		d.Set("pending_tasks_count", cluster.PendingTasksCount)
+		d.Set("running_tasks_count", cluster.RunningTasksCount)
+		d.Set("registered_container_instances_count", cluster.RegisteredContainerInstancesCount)
 	}
 
-	if c == nil {
+	if d.Id() == "" {
 		return fmt.Errorf("cluster with name %q not found", d.Get("cluster_name").(string))
 	}
 
-	d.SetId(aws.StringValue(c.ClusterArn))
-	d.Set("status", c.Status)
-	d.Set("pending_tasks_count", c.PendingTasksCount)
-	d.Set("running_tasks_count", c.RunningTasksCount)
-	d.Set("registered_container_instances_count", c.RegisteredContainerInstancesCount)
-
 	return nil
 }

builtin/providers/aws/data_source_aws_ecs_cluster_test.go

@@ -1,7 +1,10 @@
 package aws
 
 import (
+	"fmt"
+	"math/rand"
 	"testing"
+	"time"
 
 	"github.com/hashicorp/terraform/helper/resource"
 )
@@ -24,12 +27,35 @@ func TestAccAWSEcsDataSource_ecsCluster(t *testing.T) {
 	})
 }
 
-const testAccCheckAwsEcsClusterDataSourceConfig = `
+var testAccCheckAwsEcsClusterDataSourceConfig = fmt.Sprintf(`
 resource "aws_ecs_cluster" "default" {
-  name = "default"
+  name = "default-%d"
+}
+
+resource "aws_ecs_task_definition" "mongo" {
+  family = "mongodb"
+  container_definitions = <<DEFINITION
+[
+  {
+    "cpu": 128,
+    "essential": true,
+    "image": "mongo:latest",
+    "memory": 128,
+    "memoryReservation": 64,
+    "name": "mongodb"
+  }
+]
+DEFINITION
+}
+
+resource "aws_ecs_service" "mongo" {
+  name = "mongodb"
+  cluster = "${aws_ecs_cluster.default.id}"
+  task_definition = "${aws_ecs_task_definition.mongo.arn}"
+  desired_count = 1
 }
 
 data "aws_ecs_cluster" "default" {
   cluster_name = "${aws_ecs_cluster.default.name}"
 }
-`
+`, rand.New(rand.NewSource(time.Now().UnixNano())).Int())