Add ability to modify chart in MongoDB and MysqlDB structs (#1637)

* Add ability to configure MongoDB app via Options

* after review
added interface HelmApp and implemented in MongoDB and MysqlDB structs

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

pkg/app/helm_app.go

@@ -0,0 +1,11 @@
+package app
+
+import "github.com/kanisterio/kanister/pkg/helm"
+
+type HelmApp interface {
+	App
+	// Chart returns the chart of this Helm app.
+	Chart() *helm.ChartInfo
+	// SetChart sets the chart of this Helm app.
+	SetChart(chart helm.ChartInfo)
+}

pkg/app/mongodb.go

@@ -41,6 +41,8 @@ type IsMasterOutput struct {
 	Ismaster bool `json:"ismaster"`
 }
 
+var _ HelmApp = &MongoDB{}
+
 type MongoDB struct {
 	cli       kubernetes.Interface
 	namespace string
@@ -50,7 +52,7 @@ type MongoDB struct {
 }
 
 // Last tested working version "9.0.0"
-func NewMongoDB(name string) App {
+func NewMongoDB(name string) HelmApp {
 	return &MongoDB{
 		username: "root",
 		name:     name,
@@ -70,6 +72,14 @@ func NewMongoDB(name string) App {
 	}
 }
 
+func (mongo *MongoDB) Chart() *helm.ChartInfo {
+	return &mongo.chart
+}
+
+func (mongo *MongoDB) SetChart(chart helm.ChartInfo) {
+	mongo.chart = chart
+}
+
 func (mongo *MongoDB) Init(ctx context.Context) error {
 	// Instantiate Client SDKs
 	cfg, err := kube.LoadConfig()

pkg/app/mysql.go

@@ -42,19 +42,11 @@ type MysqlDB struct {
 	chart     helm.ChartInfo
 }
 
-type MysqlDBOptions func(*MysqlDB)
-
-func MysqlDBChartValues(values map[string]string) MysqlDBOptions {
-	return func(db *MysqlDB) {
-		for k, v := range values {
-			db.chart.Values[k] = v
-		}
-	}
-}
+var _ HelmApp = &MysqlDB{}
 
 // Last tested working version "6.14.11"
-func NewMysqlDB(name string, opts ...MysqlDBOptions) App {
-	m := MysqlDB{
+func NewMysqlDB(name string) HelmApp {
+	return &MysqlDB{
 		name: name,
 		chart: helm.ChartInfo{
 			Release:  appendRandString(name),
@@ -67,10 +59,14 @@ func NewMysqlDB(name string, opts ...MysqlDBOptions) App {
 			},
 		},
 	}
-	for _, opt := range opts {
-		opt(&m)
-	}
-	return &m
+}
+
+func (mdb *MysqlDB) Chart() *helm.ChartInfo {
+	return &mdb.chart
+}
+
+func (mdb *MysqlDB) SetChart(chart helm.ChartInfo) {
+	mdb.chart = chart
 }
 
 func (mdb *MysqlDB) Init(ctx context.Context) error {