Alerting: Add MissingSeriesEvalsToResolve to the APIs (#102150)

What is this feature?

A follow-up for #101184, adds AlertRule.MissingSeriesEvalsToResolve to the APIs.

missing_series_evals_to_resolve must be specified too and it must be > 0.

POST /api/ruler/grafana/api/v1/rules/{folderUID} works in the following way:

    If missing_series_evals_to_resolve is not sent or null, the rule keeps its existing value
    If missing_series_evals_to_resolve > 0: updates to that value
    If missing_series_evals_to_resolve = 0: resets to default (nil).
    AlertRule.MissingSeriesEvalsToResolve can't be 0, so I used it to reset

In the Provisioning API, the value is just set if present and > 0. Otherwise it's reset:

PUT to /api/v1/provisioning/alert-rules/{UID}:

    If missing_series_evals_to_resolve is nil, it's reset to the default value
    If missing_series_evals_to_resolve > 0, it's updated

pkg/services/ngalert/api/api_provisioning_test.go

@@ -408,6 +408,42 @@ func TestProvisioningApi(t *testing.T) {
 				updated := deserializeRule(t, response.Body())
 				require.Equal(t, rule.UID, updated.UID)
 			})
+
+			t.Run("PUT without MissingSeriesEvalsToResolve clears the field", func(t *testing.T) {
+				oldValue := util.Pointer(5)
+				sut := createProvisioningSrvSut(t)
+				rc := createTestRequestCtx()
+				rule := createTestAlertRule("rule", 1)
+				rule.MissingSeriesEvalsToResolve = oldValue
+				insertRule(t, sut, rule)
+				rule.MissingSeriesEvalsToResolve = nil
+
+				response := sut.RoutePutAlertRule(&rc, rule, rule.UID)
+				require.Equal(t, 200, response.Status(), string(response.Body()))
+				require.NotEmpty(t, response.Body())
+				updated := deserializeRule(t, response.Body())
+				require.Equal(t, rule.UID, updated.UID)
+				require.Nil(t, updated.MissingSeriesEvalsToResolve)
+			})
+
+			t.Run("PUT with MissingSeriesEvalsToResolve updates the value", func(t *testing.T) {
+				oldValue := util.Pointer(5)
+				newValue := util.Pointer(10)
+				sut := createProvisioningSrvSut(t)
+				rc := createTestRequestCtx()
+				rule := createTestAlertRule("rule", 1)
+				rule.MissingSeriesEvalsToResolve = oldValue
+				insertRule(t, sut, rule)
+				rule.MissingSeriesEvalsToResolve = newValue
+
+				response := sut.RoutePutAlertRule(&rc, rule, rule.UID)
+				require.Equal(t, 200, response.Status(), string(response.Body()))
+				require.NotEmpty(t, response.Body())
+				updated := deserializeRule(t, response.Body())
+				require.Equal(t, rule.UID, updated.UID)
+				require.NotNil(t, updated.MissingSeriesEvalsToResolve)
+				require.Equal(t, *newValue, *updated.MissingSeriesEvalsToResolve)
+			})
 		})
 
 		t.Run("exist in non-default orgs", func(t *testing.T) {
@@ -657,6 +693,47 @@ func TestProvisioningApi(t *testing.T) {
 				require.Contains(t, string(response.Body()), "invalid alert rule")
 			})
 		})
+
+		t.Run("are valid", func(t *testing.T) {
+			t.Run("PUT returns 200", func(t *testing.T) {
+				sut := createProvisioningSrvSut(t)
+				rc := createTestRequestCtx()
+				group := createTestAlertRuleGroup(1)
+
+				response := sut.RoutePutAlertRuleGroup(&rc, group, "folder-uid", group.Title)
+
+				require.Equal(t, 200, response.Status())
+				require.NotEmpty(t, response.Body())
+
+				updated := deserializeRuleGroup(t, response.Body())
+				require.Equal(t, group.Title, updated.Title)
+			})
+
+			t.Run("PUT with MissingSeriesEvalsToResolve updates the value", func(t *testing.T) {
+				sut := createProvisioningSrvSut(t)
+				rc := createTestRequestCtx()
+				group := createTestAlertRuleGroup(1)
+
+				response := sut.RoutePutAlertRuleGroup(&rc, group, "folder-uid", group.Title)
+				updated := deserializeRuleGroup(t, response.Body())
+				require.Nil(t, updated.Rules[0].MissingSeriesEvalsToResolve)
+
+				// Put the same group with a new value
+				group.Rules[0].MissingSeriesEvalsToResolve = util.Pointer(5)
+				response = sut.RoutePutAlertRuleGroup(&rc, group, "folder-uid", group.Title)
+				require.Equal(t, 200, response.Status())
+				updated = deserializeRuleGroup(t, response.Body())
+				require.NotNil(t, updated.Rules[0].MissingSeriesEvalsToResolve)
+				require.Equal(t, 5, *updated.Rules[0].MissingSeriesEvalsToResolve)
+
+				// Reset the value again
+				group.Rules[0].MissingSeriesEvalsToResolve = nil
+				response = sut.RoutePutAlertRuleGroup(&rc, group, "folder-uid", group.Title)
+				require.Equal(t, 200, response.Status())
+				updated = deserializeRuleGroup(t, response.Body())
+				require.Nil(t, updated.Rules[0].MissingSeriesEvalsToResolve)
+			})
+		})
 	})
 
 	t.Run("exports", func(t *testing.T) {
@@ -2178,6 +2255,18 @@ func createInvalidAlertRuleGroup() definitions.AlertRuleGroup {
 	}
 }
 
+func createTestAlertRuleGroup(orgID int64) definitions.AlertRuleGroup {
+	return definitions.AlertRuleGroup{
+		Title:    "test rule group",
+		Interval: 60,
+		Rules: []definitions.ProvisionedAlertRule{
+			createTestAlertRule("test-alert-rule", orgID),
+			createTestAlertRule("test-alert-rule-2", orgID),
+			createTestRecordingRule("test-recording-rule", orgID),
+		},
+	}
+}
+
 func createTestAlertRuleWithFolderAndGroup(title string, orgID int64, folderUid string, group string) definitions.ProvisionedAlertRule {
 	rule := createTestAlertRule(title, orgID)
 	rule.FolderUID = folderUid
@@ -2256,6 +2345,15 @@ func insertRuleInOrg(t *testing.T, srv ProvisioningSrv, rule definitions.Provisi
 	require.Equal(t, 201, resp.Status())
 }
 
+func deserializeRuleGroup(t *testing.T, data []byte) definitions.AlertRuleGroup {
+	t.Helper()
+
+	var rule definitions.AlertRuleGroup
+	err := json.Unmarshal(data, &rule)
+	require.NoError(t, err)
+	return rule
+}
+
 func deserializeRule(t *testing.T, data []byte) definitions.ProvisionedAlertRule {
 	t.Helper()