Alerting: Add rule conversion package (#100224)

pkg/services/ngalert/models/alert_rule.go

@@ -295,7 +295,8 @@ type AlertRule struct {
 }
 
 type AlertRuleMetadata struct {
-	EditorSettings EditorSettings `json:"editor_settings"`
+	EditorSettings      EditorSettings       `json:"editor_settings"`
+	PrometheusStyleRule *PrometheusStyleRule `json:"prometheus_style_rule,omitempty"`
 }
 
 type EditorSettings struct {
@@ -303,6 +304,10 @@ type EditorSettings struct {
 	SimplifiedNotificationsSection       bool `json:"simplified_notifications_section"`
 }
 
+type PrometheusStyleRule struct {
+	OriginalRuleDefinition string `json:"original_rule_definition,omitempty"`
+}
+
 // Namespaced describes a class of resources that are stored in a specific namespace.
 type Namespaced interface {
 	GetNamespaceUID() string
@@ -748,6 +753,11 @@ func (alertRule *AlertRule) Copy() *AlertRule {
 		}
 	}
 
+	if alertRule.Metadata.PrometheusStyleRule != nil {
+		prometheusStyleRule := *alertRule.Metadata.PrometheusStyleRule
+		result.Metadata.PrometheusStyleRule = &prometheusStyleRule
+	}
+
 	for _, s := range alertRule.NotificationSettings {
 		result.NotificationSettings = append(result.NotificationSettings, CopyNotificationSettings(s))
 	}

pkg/services/ngalert/models/alert_rule_test.go

@@ -841,7 +841,7 @@ func TestDiff(t *testing.T) {
 		}
 	})
 
-	t.Run("should detect changes in Metadata", func(t *testing.T) {
+	t.Run("should detect changes in Metadata.EditorSettings", func(t *testing.T) {
 		rule1 := RuleGen.With(RuleGen.WithMetadata(AlertRuleMetadata{EditorSettings: EditorSettings{
 			SimplifiedQueryAndExpressionsSection: false,
 			SimplifiedNotificationsSection:       false,
@@ -858,6 +858,21 @@ func TestDiff(t *testing.T) {
 			"Metadata.EditorSettings.SimplifiedNotificationsSection",
 		}, diff.Paths())
 	})
+
+	t.Run("should detect changes in Metadata.PrometheusStyleRule", func(t *testing.T) {
+		rule1 := RuleGen.With(RuleGen.WithMetadata(AlertRuleMetadata{PrometheusStyleRule: &PrometheusStyleRule{
+			OriginalRuleDefinition: "data",
+		}})).GenerateRef()
+
+		rule2 := CopyRule(rule1, RuleGen.WithMetadata(AlertRuleMetadata{PrometheusStyleRule: &PrometheusStyleRule{
+			OriginalRuleDefinition: "updated data",
+		}}))
+
+		diff := rule1.Diff(rule2)
+		assert.ElementsMatch(t, []string{
+			"Metadata.PrometheusStyleRule.OriginalRuleDefinition",
+		}, diff.Paths())
+	})
 }
 
 func TestSortByGroupIndex(t *testing.T) {
@@ -940,11 +955,21 @@ func TestAlertRuleGetKeyWithGroup(t *testing.T) {
 }
 
 func TestAlertRuleCopy(t *testing.T) {
-	for i := 0; i < 100; i++ {
-		rule := RuleGen.GenerateRef()
+	t.Run("should return a copy of the rule", func(t *testing.T) {
+		for i := 0; i < 100; i++ {
+			rule := RuleGen.GenerateRef()
+			copied := rule.Copy()
+			require.Empty(t, rule.Diff(copied))
+		}
+	})
+
+	t.Run("should create a copy of the prometheus rule definition from the metadata", func(t *testing.T) {
+		rule := RuleGen.With(RuleGen.WithMetadata(AlertRuleMetadata{PrometheusStyleRule: &PrometheusStyleRule{
+			OriginalRuleDefinition: "data",
+		}})).GenerateRef()
 		copied := rule.Copy()
-		require.Empty(t, rule.Diff(copied))
-	}
+		require.NotSame(t, rule.Metadata.PrometheusStyleRule, copied.Metadata.PrometheusStyleRule)
+	})
 }
 
 // This test makes sure the default generator