Merge pull request #562 from docker/dns

Check VPC has DNS resolution enabled

ecs/sdk.go

@@ -105,10 +105,19 @@ func (s sdk) CreateCluster(ctx context.Context, name string) (string, error) {
 	return *response.Cluster.Status, nil
 }
 
-func (s sdk) VpcExists(ctx context.Context, vpcID string) (bool, error) {
-	logrus.Debug("CheckRequirements if VPC exists: ", vpcID)
-	_, err := s.EC2.DescribeVpcsWithContext(ctx, &ec2.DescribeVpcsInput{VpcIds: []*string{&vpcID}})
-	return err == nil, err
+func (s sdk) CheckVPC(ctx context.Context, vpcID string) error {
+	logrus.Debug("CheckRequirements on VPC : ", vpcID)
+	output, err := s.EC2.DescribeVpcAttributeWithContext(ctx, &ec2.DescribeVpcAttributeInput{
+		VpcId:     aws.String(vpcID),
+		Attribute: aws.String("enableDnsSupport"),
+	})
+	if err != nil {
+		return err
+	}
+	if !*output.EnableDnsSupport.Value {
+		return fmt.Errorf("VPC %q doesn't have DNS resolution enabled", vpcID)
+	}
+	return err
 }
 
 func (s sdk) GetDefaultVPC(ctx context.Context) (string, error) {

ecs/up.go

@@ -103,23 +103,23 @@ func (b *ecsAPIService) Up(ctx context.Context, project *types.Project) error {
 }
 
 func (b ecsAPIService) GetVPC(ctx context.Context, project *types.Project) (string, error) {
+	var vpcID string
 	//check compose file for custom VPC selected
 	if vpc, ok := project.Extensions[extensionVPC]; ok {
-		vpcID := vpc.(string)
-		ok, err := b.SDK.VpcExists(ctx, vpcID)
+		vpcID = vpc.(string)
+	} else {
+		defaultVPC, err := b.SDK.GetDefaultVPC(ctx)
 		if err != nil {
 			return "", err
 		}
-		if !ok {
-			return "", fmt.Errorf("VPC does not exist: %s", vpc)
-		}
-		return vpcID, nil
+		vpcID = defaultVPC
 	}
-	defaultVPC, err := b.SDK.GetDefaultVPC(ctx)
+
+	err := b.SDK.CheckVPC(ctx, vpcID)
 	if err != nil {
 		return "", err
 	}
-	return defaultVPC, nil
+	return vpcID, nil
 }
 
 func (b ecsAPIService) GetLoadBalancer(ctx context.Context, project *types.Project) (string, error) {