Fix an issue with MaxItems

api/handlers_users.go

@@ -392,7 +392,7 @@ func (s *server) UserListHandler(w http.ResponseWriter, r *http.Request) {
 
 	// TODO check if bucket exists and fail if it doesn't?
 	users := []*iam.User{}
-	foundGroups, err := iamService.ListGroups(r.Context(), &iam.ListGroupsInput{MaxItems: aws.Int64(1000)}, bucket)
+	foundGroups, err := iamService.ListGroups(r.Context(), &iam.ListGroupsInput{}, bucket)
 	if err != nil {
 		log.Errorf("there was an error listing groups %s", err)
 	}

iam/groups.go

@@ -132,11 +132,29 @@ func (i *IAM) ListGroups(ctx context.Context, input *iam.ListGroupsInput, bucket
 	if err != nil {
 		return []*iam.Group{}, apierror.New(apierror.ErrInternalError, "unknown error", err)
 	}
+	isTruncated := groups.IsTruncated
+	groupsList := groups.Groups
+
+	if isTruncated != nil && *isTruncated {
+		for ok := true; ok; ok = *isTruncated {
+			input.Marker = groups.Marker
+			groups, err = i.Service.ListGroupsWithContext(ctx, input)
+			if err != nil {
+				return []*iam.Group{}, apierror.New(apierror.ErrInternalError, "unknown error", err)
+			}
+			if *groups.IsTruncated != false {
+				isTruncated = groups.IsTruncated
+				groupsList = append(groupsList, groups.Groups...)
+			} else {
+				break
+			}
+		}
+	}
 
 	log.Debugf("listing iam groups for account %+v", groups)
 	var outGroups []*iam.Group
 
-	for _, group := range groups.Groups {
+	for _, group := range groupsList {
 		log.Debugf("checking if %s contains %s", aws.StringValue(group.GroupName), bucket)
 		if strings.Contains(aws.StringValue(group.GroupName), bucket) {
 			outGroups = append(outGroups, group)

iam/groups_test.go

@@ -77,6 +77,12 @@ var testFormatGroupNameInputs = []TestFormatGroupNameSet{
 	},
 }
 
+var testListGroupsDataMarkers = []string{
+	"mymarker1",
+	"mymarker2",
+	"mymarker3",
+}
+
 var testListGroupsData = []*iam.Group{
 	{
 		Arn:        aws.String("arn:aws:iam::12345678910:group/testsite.yalepages.org-spinup-BktAdmGrp"),
@@ -166,7 +172,63 @@ func (m *mockIAMClient) ListGroupsWithContext(ctx context.Context, input *iam.Li
 		return nil, m.err
 	}
 
-	return &iam.ListGroupsOutput{Groups: testListGroupsData}, nil
+	if input.Marker == nil && input.MaxItems == nil {
+		return &iam.ListGroupsOutput{Groups: testListGroupsData}, nil
+	}
+
+	if input.Marker == nil && input.MaxItems != nil {
+		maxItems := aws.Int64Value(input.MaxItems) << 32
+		itemsLen := len(testListGroupsData)
+		g := int(maxItems)
+
+		var groups []*iam.Group
+
+		if g > itemsLen {
+			g = itemsLen
+		}
+
+		for i := 0; i < g; i++ {
+			groups = append(groups, testListGroupsData[i])
+		}
+
+		return &iam.ListGroupsOutput{Groups: groups}, nil
+	}
+
+	if input.Marker != nil && input.MaxItems != nil {
+		markerIndex := -1
+		startIndex := -1
+		itemsLen := len(testListGroupsData)
+
+		for i := 0; i < len(testListGroupsDataMarkers); i++ {
+			m := testListGroupsDataMarkers[i]
+			if m == *input.Marker {
+				markerIndex = i
+			}
+		}
+
+		if markerIndex == -1 {
+			return &iam.ListGroupsOutput{}, nil
+		}
+
+		startIndex = markerIndex
+		maxItems := aws.Int64Value(input.MaxItems) << 32
+		itemsLen = len(testListGroupsData) - startIndex
+		g := int(maxItems)
+
+		var groups []*iam.Group
+
+		if g > itemsLen {
+			g = itemsLen
+		}
+
+		for i := startIndex; i < g; i++ {
+			groups = append(groups, testListGroupsData[i])
+		}
+
+		return &iam.ListGroupsOutput{Groups: groups}, nil
+	}
+
+	return &iam.ListGroupsOutput{}, nil
 }
 
 func (m *mockIAMClient) CreateGroupWithContext(ctx context.Context, input *iam.CreateGroupInput, opts ...request.Option) (*iam.CreateGroupOutput, error) {
@@ -238,6 +300,15 @@ func TestListGroups(t *testing.T) {
 		t.Errorf("expected %+v, got %+v", testListGroupsExpected, listResult)
 	}
 
+	listResultMaxItemsConstrain, err := i.ListGroups(context.TODO(), &iam.ListGroupsInput{MaxItems: aws.Int64(1)}, "testsite.yalepages.org")
+	if err != nil {
+		t.Errorf("expected nil error, got %s", err)
+	}
+
+	if !reflect.DeepEqual(listResultMaxItemsConstrain, testListGroupsExpected) {
+		t.Errorf("expected %+v, got %+v", testListGroupsExpected, listResultMaxItemsConstrain)
+	}
+
 	listResult, err = i.ListGroups(context.TODO(), &iam.ListGroupsInput{}, "anothersite.yalepages.org")
 	if err != nil {
 		t.Errorf("expected nil error, got %s", err)