From 3834620b35e3e5b261d3eb8518013591e0fdbf6b Mon Sep 17 00:00:00 2001
From: Mustafa Abdelrahman <mustafa.abdelrahman@zalando.de>
Date: Tue, 9 Jan 2024 10:40:29 +0100
Subject: [PATCH] Add testcase for stack coming without tg tag and in
 `ROLLBACK_IN_PROGRESS` state

Signed-off-by: Mustafa Abdelrahman <mustafa.abdelrahman@zalando.de>
---
 aws/cf.go      |  2 +-
 aws/cf_test.go | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/aws/cf.go b/aws/cf.go
index 3a481515..9eb3a6d4 100644
--- a/aws/cf.go
+++ b/aws/cf.go
@@ -488,12 +488,12 @@ func mapToManagedStack(stack *cloudformation.Stack) *Stack {
 
 	// If the stack is in rollback state, the outputs are not available.
 	// We need to store target group ARNs in the tags.
+	// To restore the ARNs, and keep sending traffic to the right target groups.
 	if aws.StringValue(stack.StackStatus) == cloudformation.StackStatusRollbackInProgress && len(tgARNs) == 0 {
 		if tgARNsTag, ok := tags[targetGroupsArnsTag]; ok {
 			values, err := base64.StdEncoding.DecodeString(tgARNsTag)
 			if err != nil {
 				log.Errorf("failed to decode target group ARNs from tags: %v", err)
-				tgARNs = []string{}
 			} else {
 				tgARNs = strings.Split(string(values), ",")
 			}
diff --git a/aws/cf_test.go b/aws/cf_test.go
index a3d27ec3..e247077d 100644
--- a/aws/cf_test.go
+++ b/aws/cf_test.go
@@ -570,6 +570,41 @@ func TestFindManagedStacks(t *testing.T) {
 				},
 			},
 		},
+		{
+			name: "successfull-call-with-rollback-status-and-no-tg-tag",
+			given: fake.CFOutputs{
+				DescribeStackPages: fake.R(nil, nil),
+				DescribeStacks: fake.R(&cloudformation.DescribeStacksOutput{
+					Stacks: []*cloudformation.Stack{
+						{
+							StackName:   aws.String("managed-stack-rolling-back"),
+							StackStatus: aws.String(cloudformation.StackStatusRollbackInProgress),
+							Tags: []*cloudformation.Tag{
+								cfTag(kubernetesCreatorTag, DefaultControllerID),
+								cfTag(clusterIDTagPrefix+"test-cluster", resourceLifecycleOwned),
+								cfTag(certificateARNTagPrefix+"cert-arn", time.Time{}.Format(time.RFC3339)),
+							},
+							Outputs: []*cloudformation.Output{},
+						},
+					},
+				}, nil),
+			},
+			want: []*Stack{
+				{
+					Name: "managed-stack-rolling-back",
+					CertificateARNs: map[string]time.Time{
+						"cert-arn": {},
+					},
+					tags: map[string]string{
+						kubernetesCreatorTag:                 DefaultControllerID,
+						clusterIDTagPrefix + "test-cluster":  resourceLifecycleOwned,
+						certificateARNTagPrefix + "cert-arn": time.Time{}.Format(time.RFC3339),
+					},
+					status: cloudformation.StackStatusRollbackInProgress,
+					HTTP2:  true,
+				},
+			},
+		},
 		{
 			name: "no-ready-stacks",
 			given: fake.CFOutputs{