Alerting: replace usage of simplejson to json.RawMessage in NotificationChannelConfig (#60423)

* introduce alias for json.RawMessage with name RawMessage. This is needed to keep raw JSON and implement a marshaler for YAML, which does not seem to be used but there are tests that fail.
* replace usage of simplejson with RawMessage in NotificationChannelConfig
* remove usage of simplejson in tests
* change migration code to convert simplejson to raw message

pkg/services/ngalert/api/tooling/definitions/alertmanager.go

@@ -17,7 +17,6 @@ import (
 	"github.com/prometheus/common/model"
 	"gopkg.in/yaml.v3"
 
-	"github.com/grafana/grafana/pkg/components/simplejson"
 	"github.com/grafana/grafana/pkg/services/ngalert/models"
 	"github.com/grafana/grafana/pkg/services/secrets"
 	"github.com/grafana/grafana/pkg/util"
@@ -964,12 +963,54 @@ func AllReceivers(route *config.Route) (res []string) {
 	return res
 }
 
+type RawMessage json.RawMessage // This type alias adds YAML marshaling to the json.RawMessage.
+
+// MarshalJSON returns m as the JSON encoding of m.
+func (r RawMessage) MarshalJSON() ([]byte, error) {
+	return json.Marshal(json.RawMessage(r))
+}
+
+func (r *RawMessage) UnmarshalJSON(data []byte) error {
+	var raw json.RawMessage
+	err := json.Unmarshal(data, &raw)
+	if err != nil {
+		return err
+	}
+	*r = RawMessage(raw)
+	return nil
+}
+
+func (r *RawMessage) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	var data interface{}
+	if err := unmarshal(&data); err != nil {
+		return err
+	}
+	bytes, err := json.Marshal(data)
+	if err != nil {
+		return err
+	}
+	*r = bytes
+	return nil
+}
+
+func (r RawMessage) MarshalYAML() (interface{}, error) {
+	if r == nil {
+		return nil, nil
+	}
+	var d interface{}
+	err := json.Unmarshal(r, &d)
+	if err != nil {
+		return nil, err
+	}
+	return d, nil
+}
+
 type GettableGrafanaReceiver struct {
 	UID                   string            `json:"uid"`
 	Name                  string            `json:"name"`
 	Type                  string            `json:"type"`
 	DisableResolveMessage bool              `json:"disableResolveMessage"`
-	Settings              *simplejson.Json  `json:"settings"`
+	Settings              RawMessage        `json:"settings,omitempty"`
 	SecureFields          map[string]bool   `json:"secureFields"`
 	Provenance            models.Provenance `json:"provenance,omitempty"`
 }
@@ -979,7 +1020,7 @@ type PostableGrafanaReceiver struct {
 	Name                  string            `json:"name"`
 	Type                  string            `json:"type"`
 	DisableResolveMessage bool              `json:"disableResolveMessage"`
-	Settings              *simplejson.Json  `json:"settings"`
+	Settings              RawMessage        `json:"settings,omitempty"`
 	SecureSettings        map[string]string `json:"secureSettings"`
 }
 

pkg/services/ngalert/api/tooling/definitions/alertmanager_test.go

@@ -1040,3 +1040,49 @@ func Test_Marshaling_Validation(t *testing.T) {
 	expected := []model.LabelName{"alertname"}
 	require.Equal(t, expected, tmp.AlertmanagerConfig.Config.Route.GroupBy)
 }
+
+func Test_RawMessageMarshaling(t *testing.T) {
+	type Data struct {
+		Field RawMessage `json:"field" yaml:"field"`
+	}
+
+	t.Run("should unmarshal nil", func(t *testing.T) {
+		v := Data{
+			Field: nil,
+		}
+		data, err := json.Marshal(v)
+		require.NoError(t, err)
+		assert.JSONEq(t, `{ "field": null }`, string(data))
+
+		var n Data
+		require.NoError(t, json.Unmarshal(data, &n))
+		assert.Equal(t, RawMessage("null"), n.Field)
+
+		data, err = yaml.Marshal(&v)
+		require.NoError(t, err)
+		assert.Equal(t, "field: null\n", string(data))
+
+		require.NoError(t, yaml.Unmarshal(data, &n))
+		assert.Nil(t, n.Field)
+	})
+
+	t.Run("should unmarshal value", func(t *testing.T) {
+		v := Data{
+			Field: RawMessage(`{ "data": "test"}`),
+		}
+		data, err := json.Marshal(v)
+		require.NoError(t, err)
+		assert.JSONEq(t, `{"field":{"data":"test"}}`, string(data))
+
+		var n Data
+		require.NoError(t, json.Unmarshal(data, &n))
+		assert.Equal(t, RawMessage(`{"data":"test"}`), n.Field)
+
+		data, err = yaml.Marshal(&v)
+		require.NoError(t, err)
+		assert.Equal(t, "field:\n    data: test\n", string(data))
+
+		require.NoError(t, yaml.Unmarshal(data, &n))
+		assert.Equal(t, RawMessage(`{"data":"test"}`), n.Field)
+	})
+}

pkg/services/ngalert/api/tooling/definitions/provisioning_contactpoints.go

@@ -108,8 +108,12 @@ func (e *EmbeddedContactPoint) Valid(decryptFunc channels.GetDecryptedValueFn) e
 	if !exists {
 		return fmt.Errorf("unknown type '%s'", e.Type)
 	}
+	jsonBytes, err := e.Settings.MarshalJSON()
+	if err != nil {
+		return err
+	}
 	cfg, _ := channels.NewFactoryConfig(&channels.NotificationChannelConfig{
-		Settings: e.Settings,
+		Settings: jsonBytes,
 		Type:     e.Type,
 	}, nil, decryptFunc, nil, nil, func(ctx ...interface{}) channels.Logger {
 		return &channels.FakeLogger{}