From 2322d3ae6bde7d91af77c137601a7492cb3ae5e4 Mon Sep 17 00:00:00 2001
From: Anthony Dong <adongy@users.noreply.github.com>
Date: Thu, 25 Jun 2020 10:48:24 +0200
Subject: [PATCH] aws: retry fetching blockdevicemapping if empty

---
 builder/amazon/common/step_run_spot_instance.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/builder/amazon/common/step_run_spot_instance.go b/builder/amazon/common/step_run_spot_instance.go
index 0f9e65aaf..a07aad5e5 100644
--- a/builder/amazon/common/step_run_spot_instance.go
+++ b/builder/amazon/common/step_run_spot_instance.go
@@ -324,6 +324,9 @@ func (s *StepRunSpotInstance) Run(ctx context.Context, state multistep.StateBag)
 		describeOutput, err = ec2conn.DescribeInstances(&ec2.DescribeInstancesInput{
 			InstanceIds: []*string{aws.String(instanceId)},
 		})
+		if len(describeOutput.Reservations) > 0 && len(describeOutput.Reservations[0].Instances) > 0 && len(describeOutput.Reservations[0].Instances[0].BlockDeviceMappings) == 0 {
+			return fmt.Errorf("Instance has no block devices")
+		}
 		return err
 	})
 	if err != nil || len(describeOutput.Reservations) == 0 || len(describeOutput.Reservations[0].Instances) == 0 {