Allow deleted label names to be replaced (#1309)

Fixes #1310

server/datastore/datastore_labels_test.go

@@ -386,3 +386,42 @@ func testSaveLabel(t *testing.T, db kolide.Datastore) {
 	assert.Equal(t, label.Name, saved.Name)
 	assert.Equal(t, label.Description, saved.Description)
 }
+
+func testReplaceDeletedLabel(t *testing.T, db kolide.Datastore) {
+	if db.Name() == "inmem" {
+		t.Skip("inmem is being deprecated, test skipped")
+	}
+
+	label := &kolide.Label{
+		Name:  "my label",
+		Query: "select 1 from processes;",
+	}
+	saved, err := db.NewLabel(label)
+	require.Nil(t, err)
+
+	saved, err = db.Label(saved.ID)
+	require.Nil(t, err)
+	assert.Equal(t, label.Name, saved.Name)
+	assert.Equal(t, label.Description, saved.Description)
+
+	newLabel := &kolide.Label{
+		Name:  "my label",
+		Query: " select * from time",
+	}
+
+	// Replace should fail when label already exists and isn't soft deleted
+	_, err = db.NewLabel(newLabel)
+	require.NotNil(t, err)
+
+	// Now delete label and replace should succeed
+	err = db.DeleteLabel(label.ID)
+	require.Nil(t, err)
+
+	saved, err = db.NewLabel(newLabel)
+	require.Nil(t, err)
+
+	saved, err = db.Label(saved.ID)
+	require.Nil(t, err)
+	assert.Equal(t, newLabel.Name, saved.Name)
+	assert.Equal(t, newLabel.Description, saved.Description)
+}

server/datastore/datastore_test.go

@@ -73,4 +73,5 @@ var testFunctions = [...]func(*testing.T, kolide.Datastore){
 	testLicense,
 	testSaveLabel,
 	testFlappingNetworkInterfaces,
+	testReplaceDeletedLabel,
 }

server/datastore/mysql/labels.go

@@ -11,8 +11,25 @@ import (
 
 // NewLabel creates a new kolide.Label
 func (d *Datastore) NewLabel(label *kolide.Label) (*kolide.Label, error) {
-
-	sql := `
+	var (
+		deletedLabel kolide.Label
+		query        string
+	)
+	err := d.db.Get(&deletedLabel,
+		"SELECT * FROM labels WHERE name = ? AND deleted", label.Name)
+	switch err {
+	case nil:
+		query = `
+		REPLACE INTO labels (
+			name,
+			description,
+			query,
+			platform,
+			label_type
+		) VALUES ( ?, ?, ?, ?, ?)
+	`
+	case sql.ErrNoRows:
+		query = `
 		INSERT INTO labels (
 			name,
 			description,
@@ -21,7 +38,10 @@ func (d *Datastore) NewLabel(label *kolide.Label) (*kolide.Label, error) {
 			label_type
 		) VALUES ( ?, ?, ?, ?, ?)
 	`
-	result, err := d.db.Exec(sql, label.Name, label.Description, label.Query, label.Platform, label.LabelType)
+	default:
+		return nil, errors.Wrap(err, "check for existing label")
+	}
+	result, err := d.db.Exec(query, label.Name, label.Description, label.Query, label.Platform, label.LabelType)
 	if err != nil {
 		return nil, errors.Wrap(err, "inserting label")
 	}

server/service/endpoint_labels.go

@@ -119,11 +119,17 @@ func (r createLabelResponse) error() error { return r.Err }
 func makeCreateLabelEndpoint(svc kolide.Service) endpoint.Endpoint {
 	return func(ctx context.Context, request interface{}) (interface{}, error) {
 		req := request.(createLabelRequest)
+
 		label, err := svc.NewLabel(ctx, req.payload)
+		if err != nil {
+			return createLabelResponse{Err: err}, nil
+		}
+
 		labelResp, err := labelResponseForLabel(ctx, svc, label)
 		if err != nil {
 			return createLabelResponse{Err: err}, nil
 		}
+
 		return createLabelResponse{Label: *labelResp}, nil
 	}
 }