feat: add new validator keepFiringForIsNotLongerThan

Signed-off-by: Martin Chodur <[email protected]>

docs/validations.md

@@ -46,6 +46,7 @@ All the supported validations are listed here. The validations are grouped by th
       - [`validateAnnotationTemplates`](#validateannotationtemplates)
     - [Other](#other-1)
       - [`forIsNotLongerThan`](#forisnotlongerthan)
+      - [`keepFiringForIsNotLongerThan`](#keepfiringforisnotlongerthan)
   - [Recording rules validators](#recording-rules-validators)
 
 
@@ -419,5 +420,14 @@ params:
   limit: "1h"
 ```
 
+#### `keepFiringForIsNotLongerThan`
+
+Fails if the alert uses longer `keep_firing_for` than the specified limit.
+
+```yaml
+params:
+  limit: "1h"
+```
+
 ## Recording rules validators
 Validators that can be used on `Recording rule` scope.

examples/human_readable.html

@@ -44,6 +44,7 @@ <h2><a href="#check-metric-name">check-metric-name</a></h2>
 	  <ul>
 		<li>Alert expression uses metric name in selectors</li>
 		<li>Alert labels are valid templates</li>
+		<li>Alert <code>keep_firing_for</code> is not longer than <code>1h</code></li>
 	  </ul>
 
   <h2><a href="#check-groups">check-groups</a></h2>

examples/human_readable.md

@@ -31,6 +31,7 @@ Validation rules:
   check-metric-name
     - Alert expression uses metric name in selectors
     - Alert labels are valid templates
+    - Alert `keep_firing_for` is not longer than `1h`
 
   check-groups
     - Group does not have other `source_tenants` than: `tenant1`, `tenant2`, `k8s`

examples/validation.yaml

@@ -84,6 +84,9 @@ validationRules:
     validations:
       - type: expressionWithNoMetricName
       - type: validateLabelTemplates
+      - type: keepFiringForIsNotLongerThan
+        params:
+          limit: "1h"
 
   - name: check-groups
     scope: Group

pkg/validator/alert.go

@@ -44,6 +44,31 @@ func (h forIsNotLongerThan) Validate(_ unmarshaler.RuleGroup, rule rulefmt.Rule,
 	return nil
 }
 
+func newKeepFiringForIsNotLongerThan(paramsConfig yaml.Node) (Validator, error) {
+	params := struct {
+		Limit model.Duration `yaml:"limit"`
+	}{}
+	if err := paramsConfig.Decode(&params); err != nil {
+		return nil, err
+	}
+	return &keepFiringForIsNotLongerThan{limit: params.Limit}, nil
+}
+
+type keepFiringForIsNotLongerThan struct {
+	limit model.Duration
+}
+
+func (h keepFiringForIsNotLongerThan) String() string {
+	return fmt.Sprintf("`keep_firing_for` is not longer than `%s`", h.limit)
+}
+
+func (h keepFiringForIsNotLongerThan) Validate(_ unmarshaler.RuleGroup, rule rulefmt.Rule, _ *prometheus.Client) []error {
+	if rule.KeepFiringFor > h.limit {
+		return []error{fmt.Errorf("alert has `keep_firing_for: %s` which is longer than the specified limit of %s", rule.KeepFiringFor, h.limit)}
+	}
+	return nil
+}
+
 func newValidateLabelTemplates(paramsConfig yaml.Node) (Validator, error) {
 	params := struct{}{}
 	if err := paramsConfig.Decode(&params); err != nil {

pkg/validator/config.go

@@ -38,7 +38,8 @@ var registeredUniversalRuleValidators = map[string]validatorCreator{
 var registeredRecordingRuleValidators = map[string]validatorCreator{}
 
 var registeredAlertValidators = map[string]validatorCreator{
-	"forIsNotLongerThan": newForIsNotLongerThan,
+	"forIsNotLongerThan":           newForIsNotLongerThan,
+	"keepFiringForIsNotLongerThan": newKeepFiringForIsNotLongerThan,
 
 	"validateAnnotationTemplates": newValidateAnnotationTemplates,
 	"annotationIsValidPromQL":     newAnnotationIsValidPromQL,

pkg/validator/validator_test.go

@@ -243,6 +243,10 @@ var testCases = []struct {
 	{name: "noTemplate", validator: validateLabelTemplates{}, rule: rulefmt.Rule{Labels: map[string]string{"foo": "bar"}}, expectedErrors: 0},
 	{name: "validLabelTemplate", validator: validateLabelTemplates{}, rule: rulefmt.Rule{Labels: map[string]string{"foo": "foo {{ $value | humanizeDuration }} bar"}}, expectedErrors: 0},
 	{name: "invalidLabelTemplate", validator: validateLabelTemplates{}, rule: rulefmt.Rule{Labels: map[string]string{"foo": "foo {{ $value | huuuuumanizeDuration }} bar"}}, expectedErrors: 1},
+
+	// keepFiringForIsNotLongerThan
+	{name: "keepFiringForIsNotLongerThanOK", validator: keepFiringForIsNotLongerThan{limit: model.Duration(time.Minute)}, rule: rulefmt.Rule{KeepFiringFor: model.Duration(time.Second)}, expectedErrors: 0},
+	{name: "keepFiringForIsNotLongerThanWrong", validator: keepFiringForIsNotLongerThan{limit: model.Duration(time.Minute)}, rule: rulefmt.Rule{KeepFiringFor: model.Duration(time.Minute * 2)}, expectedErrors: 1},
 }
 
 func Test(t *testing.T) {