Add rule/for check

cmd/pint/tests/0025_config.txt

@@ -84,6 +84,7 @@ level=info msg="Loading configuration file" path=.pint.hcl
       "query/cost",
       "promql/series",
       "rule/duplicate",
+      "rule/for",
       "rule/label",
       "rule/link",
       "rule/reject"

cmd/pint/tests/0113_config_env_expand.txt

@@ -49,6 +49,7 @@ level=info msg="Loading configuration file" path=.pint.hcl
       "query/cost",
       "promql/series",
       "rule/duplicate",
+      "rule/for",
       "rule/label",
       "rule/link",
       "rule/reject"

cmd/pint/tests/0121_rule_for.txt

@@ -0,0 +1,36 @@
+pint.error --no-color lint rules
+! stdout .
+cmp stderr stderr.txt
+
+-- stderr.txt --
+level=info msg="Loading configuration file" path=.pint.hcl
+rules/0001.yml:6 Bug: this alert rule must have a 'for' field with a minimum duration of 5m (rule/for)
+ 6 |   for: 3m
+
+rules/0001.yml:9 Bug: this alert rule must have a 'for' field with a maximum duration of 10m (rule/for)
+ 9 |   for: 13m
+
+level=info msg="Problems found" Bug=2
+level=fatal msg="Fatal error" error="problems found"
+-- rules/0001.yml --
+- alert: ok
+  expr: up == 0
+  for: 5m
+- alert: 3m
+  expr: up == 0
+  for: 3m
+- alert: 13m
+  expr: up == 0
+  for: 13m
+
+-- .pint.hcl --
+parser {
+  relaxed = [".*"]
+}
+rule {
+  for {
+    severity = "bug"
+    min      = "5m"
+    max      = "10m"
+  }
+}

docs/changelog.md

@@ -16,6 +16,7 @@
   - alert: my alert
     expr: rate(my:sum[5m])
   ```
+- Added [rule/for](checks/rule/for.md) check.
 
 ### Changed
 

docs/checks/rule/for.md

@@ -0,0 +1,64 @@
+---
+layout: default
+parent: Checks
+grand_parent: Documentation
+---
+
+# rule/for
+
+This check allows to enforce the presence of `for` field on alerting
+rules.
+You can configure it to enforce some minimal and/or maximum duration
+set on alerts via `for` field.
+
+## Configuration
+
+This check doesn't have any configuration options.
+
+## How to enable it
+
+Syntax:
+
+```js
+for {
+  severity = "bug|warning|info"
+  min      = "5m"
+  max      = "10m"
+}
+```
+
+- `severity` - set custom severity for reported issues, defaults to a bug.
+- `min` - minimum required `for` value for matching alerting rules.
+  If not set minimum `for` duration won't be enforced.
+- `max` - maximum allowed `for` value for matching alerting rules.
+- If not set maximum `for` duration won't be enforced.
+
+## How to disable it
+
+You can disable this check globally by adding this config block:
+
+```js
+checks {
+  disabled = ["rule/for"]
+}
+```
+
+You can also disable it for all rules inside given file by adding
+a comment anywhere in that file. Example:
+
+`# pint file/disable rule/for`
+
+Or you can disable it per rule by adding a comment to it. Example:
+
+`# pint disable rule/for`
+
+## How to snooze it
+
+You can disable this check until given time by adding a comment to it. Example:
+
+`# pint snooze $TIMESTAMP rule/for`
+
+Where `$TIMESTAMP` is either use [RFC3339](https://www.rfc-editor.org/rfc/rfc3339)
+formatted  or `YYYY-MM-DD`.
+Adding this comment will disable `rule/duplicate` *until* `$TIMESTAMP`, after that
+check will be re-enabled.

internal/checks/base.go

@@ -28,6 +28,7 @@ var (
 		CostCheckName,
 		SeriesCheckName,
 		RuleDuplicateCheckName,
+		RuleForCheckName,
 		LabelCheckName,
 		RuleLinkCheckName,
 		RejectCheckName,

internal/checks/rule_for.go

@@ -0,0 +1,82 @@
+package checks
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/cloudflare/pint/internal/discovery"
+	"github.com/cloudflare/pint/internal/output"
+	"github.com/cloudflare/pint/internal/parser"
+)
+
+const (
+	RuleForCheckName = "rule/for"
+)
+
+func NewRuleForCheck(minFor, maxFor time.Duration, severity Severity) RuleForCheck {
+	return RuleForCheck{
+		minFor:   minFor,
+		maxFor:   maxFor,
+		severity: severity,
+	}
+}
+
+type RuleForCheck struct {
+	severity Severity
+	minFor   time.Duration
+	maxFor   time.Duration
+}
+
+func (c RuleForCheck) Meta() CheckMeta {
+	return CheckMeta{IsOnline: true}
+}
+
+func (c RuleForCheck) String() string {
+	return fmt.Sprintf("%s(%s:%s)", RuleForCheckName, output.HumanizeDuration(c.minFor), output.HumanizeDuration(c.maxFor))
+}
+
+func (c RuleForCheck) Reporter() string {
+	return RuleForCheckName
+}
+
+func (c RuleForCheck) Check(ctx context.Context, path string, rule parser.Rule, entries []discovery.Entry) (problems []Problem) {
+	if rule.AlertingRule == nil {
+		return nil
+	}
+
+	var forDur time.Duration
+	var fragment string
+	var lines []int
+	if rule.AlertingRule.For != nil {
+		forDur, _ = time.ParseDuration(rule.AlertingRule.For.Value.Value)
+		fragment = rule.AlertingRule.For.Value.Value
+		lines = rule.AlertingRule.For.Lines()
+	}
+	if fragment == "" {
+		fragment = rule.AlertingRule.Alert.Value.Value
+		lines = rule.AlertingRule.Alert.Lines()
+	}
+
+	if forDur < c.minFor {
+		problems = append(problems, Problem{
+			Fragment: fragment,
+			Lines:    lines,
+			Reporter: c.Reporter(),
+			Text:     fmt.Sprintf("this alert rule must have a 'for' field with a minimum duration of %s", output.HumanizeDuration(c.minFor)),
+			Severity: c.severity,
+		})
+	}
+
+	if c.maxFor > 0 && forDur > c.maxFor {
+		problems = append(problems, Problem{
+			Fragment: fragment,
+			Lines:    lines,
+			Reporter: c.Reporter(),
+			Text:     fmt.Sprintf("this alert rule must have a 'for' field with a maximum duration of %s", output.HumanizeDuration(c.maxFor)),
+			Severity: c.severity,
+		})
+	}
+
+	return problems
+}