Fix spot fleet request panic (hashicorp#9836)

Change panic to error and return it

aws/resource_aws_spot_fleet_request.go

@@ -963,25 +963,30 @@ func resourceAwsSpotFleetRequestRead(d *schema.ResourceData, meta interface{}) e
 			aws.TimeValue(config.ValidUntil).Format(time.RFC3339))
 	}
 
+	launchSpec, err := launchSpecsToSet(config.LaunchSpecifications, conn)
+	if err != nil {
+		return fmt.Errorf("error occurred while reading launch specification: %s", err)
+	}
+
 	d.Set("replace_unhealthy_instances", config.ReplaceUnhealthyInstances)
 	d.Set("instance_interruption_behaviour", config.InstanceInterruptionBehavior)
 	d.Set("fleet_type", config.Type)
-	d.Set("launch_specification", launchSpecsToSet(config.LaunchSpecifications, conn))
+	d.Set("launch_specification", launchSpec)
 
 	return nil
 }
 
-func launchSpecsToSet(launchSpecs []*ec2.SpotFleetLaunchSpecification, conn *ec2.EC2) *schema.Set {
+func launchSpecsToSet(launchSpecs []*ec2.SpotFleetLaunchSpecification, conn *ec2.EC2) (*schema.Set, error) {
 	specSet := &schema.Set{F: hashLaunchSpecification}
 	for _, spec := range launchSpecs {
 		rootDeviceName, err := fetchRootDeviceName(aws.StringValue(spec.ImageId), conn)
 		if err != nil {
-			log.Panic(err)
+			return nil, err
 		}
 
 		specSet.Add(launchSpecToMap(spec, rootDeviceName))
 	}
-	return specSet
+	return specSet, nil
 }
 
 func launchSpecToMap(l *ec2.SpotFleetLaunchSpecification, rootDevName *string) map[string]interface{} {

aws/resource_aws_spot_fleet_request_test.go

@@ -690,6 +690,24 @@ func TestAccAWSSpotFleetRequest_WithTargetGroups(t *testing.T) {
 	})
 }
 
+func TestAccAWSSpotFleetRequest_WithInstanceStoreAmi(t *testing.T) {
+	t.Skip("Test fails due to test harness constraints")
+	rName := acctest.RandString(10)
+	rInt := acctest.RandInt()
+
+	resource.ParallelTest(t, resource.TestCase{
+		PreCheck:     func() { testAccPreCheck(t); testAccPreCheckAWSEc2SpotFleetRequest(t) },
+		Providers:    testAccProviders,
+		CheckDestroy: testAccCheckAWSSpotFleetRequestDestroy,
+		Steps: []resource.TestStep{
+			{
+				Config:      testAccAWSSpotFleetRequestLaunchSpecificationWithInstanceStoreAmi(rName, rInt),
+				ExpectError: regexp.MustCompile("Instance store backed AMIs do not provide a root device name"),
+			},
+		},
+	})
+}
+
 func testAccCheckAWSSpotFleetRequestConfigRecreated(t *testing.T,
 	before, after *ec2.SpotFleetRequestConfig) resource.TestCheckFunc {
 	return func(s *terraform.State) error {
@@ -1624,6 +1642,37 @@ resource "aws_spot_fleet_request" "test" {
 `)
 }
 
+func testAccAWSSpotFleetRequestLaunchSpecificationWithInstanceStoreAmi(rName string, rInt int) string {
+	return testAccAWSSpotFleetRequestConfigBase(rName, rInt) + fmt.Sprint(`
+data "aws_ami" "ubuntu_instance_store" {
+  most_recent = true
+  owners      = ["099720109477"] # Canonical
+
+  # Latest Ubuntu 18.04 LTS amd64 instance-store HVM AMI
+  filter {
+    name   = "name"
+    values = ["ubuntu/images/hvm-instance/ubuntu-bionic-18.04-amd64-server*"]
+  }
+}
+
+resource "aws_spot_fleet_request" "foo" {
+    iam_fleet_role = "${aws_iam_role.test-role.arn}"
+    spot_price = "0.03"
+    target_capacity = 2
+    valid_until = "2019-11-04T20:44:20Z"
+    terminate_instances_with_expiration = true
+    wait_for_fulfillment = true
+
+    launch_specification {
+      ami           = "${data.aws_ami.ubuntu_instance_store.id}"
+	  instance_type = "c3.large"
+    }
+
+	depends_on = ["aws_iam_policy_attachment.test-attach"]
+}
+`)
+}
+
 func testAccAWSSpotFleetRequestTagsConfig(rName string, rInt int) string {
 	return testAccAWSSpotFleetRequestConfigBase(rName, rInt) + fmt.Sprint(`
 resource "aws_spot_fleet_request" "foo" {