Allow disabling individual query/series checks

Fixes cloudflare#112

CHANGELOG.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## v0.6.5
+
+### Added
+
+- Allow disabling `query/series` check for individual series using
+  `# pint disable query/series(my_metric_name)` comments.
+
 ## v0.6.4
 
 ### Fixed

docs/CONFIGURATION.md

@@ -725,3 +725,24 @@ groups:
     - record: instance:http_requests_total:avg_over_time:1w
       expr: avg_over_time(http_requests_total[1w]) by (instance) # pint disable query/cost
 ```
+
+Some checks allow to specify extra parameters.
+
+### query/series
+
+You can disable `query/series` for specific metric using `# pint disable query/series(selector)`
+comment.
+Just like with PromQL if a selector doesn't have any labels then it will match all instances,
+if you pass any labels it will only pass time series with those labels.
+
+Disable warnings about missing `my_metric_name`:
+
+```YAML
+# pint disable query/series(my_metric_name)
+```
+
+Disable it only for `my_metric_name{cluster="dev"}` but still warn about `my_metric_name{cluster="prod"}`:
+
+```YAML
+# pint disable query/series(my_metric_name{cluster="dev"})
+```

internal/checks/query_series.go

@@ -39,6 +39,13 @@ func (c SeriesCheck) Check(rule parser.Rule) (problems []Problem) {
 	done := map[string]bool{}
 
 	for _, selector := range getSelectors(expr.Query) {
+		bareSelector := stripLabels(selector)
+		c1 := fmt.Sprintf("disable %s(%s)", SeriesCheckName, selector.String())
+		c2 := fmt.Sprintf("disable %s(%s)", SeriesCheckName, bareSelector.String())
+		if rule.HasComment(c1) || rule.HasComment(c2) {
+			done[selector.String()] = true
+			continue
+		}
 		if _, ok := done[selector.String()]; ok {
 			continue
 		}
@@ -71,15 +78,7 @@ func (c SeriesCheck) countSeries(expr parser.PromQLExpr, selector promParser.Vec
 	if series == 0 {
 		if len(selector.LabelMatchers) > 1 {
 			// retry selector with only __name__ label
-			s := promParser.VectorSelector{
-				Name:          selector.Name,
-				LabelMatchers: []*labels.Matcher{},
-			}
-			for _, lm := range selector.LabelMatchers {
-				if lm.Name == labels.MetricName {
-					s.LabelMatchers = append(s.LabelMatchers, lm)
-				}
-			}
+			s := stripLabels(selector)
 			p := c.countSeries(expr, s)
 			// if we have zero series without any label selector then the whole
 			// series is missing, but if we have some then report missing series
@@ -118,3 +117,16 @@ func getSelectors(n *parser.PromQLNode) (selectors []promParser.VectorSelector)
 
 	return
 }
+
+func stripLabels(selector promParser.VectorSelector) promParser.VectorSelector {
+	s := promParser.VectorSelector{
+		Name:          selector.Name,
+		LabelMatchers: []*labels.Matcher{},
+	}
+	for _, lm := range selector.LabelMatchers {
+		if lm.Name == labels.MetricName {
+			s.LabelMatchers = append(s.LabelMatchers, lm)
+		}
+	}
+	return s
+}

internal/checks/query_series_test.go

@@ -22,7 +22,7 @@ func TestSeriesCheck(t *testing.T) {
 		query := r.Form.Get("query")
 
 		switch query {
-		case "count(notfound)", `count({__name__="notfound",job="bar"})`:
+		case "count(notfound)", `count(notfound{job="foo"})`, `count(notfound{job!="foo"})`, `count({__name__="notfound",job="bar"})`:
 			w.WriteHeader(200)
 			w.Header().Set("Content-Type", "application/json")
 			_, _ = w.Write([]byte(`{
@@ -241,6 +241,51 @@ func TestSeriesCheck(t *testing.T) {
 				},
 			},
 		},
+		{
+			description: "series missing but check disabled",
+			content: `
+# pint disable query/series(notfound)
+- record: foo
+  expr: count(notfound) == 0
+`,
+			checker: checks.NewSeriesCheck("prom", srv.URL, time.Second*5),
+		},
+		{
+			description: "series missing but check disabled, labels",
+			content: `
+# pint disable query/series(notfound)
+- record: foo
+  expr: count(notfound{job="foo"}) == 0
+`,
+			checker: checks.NewSeriesCheck("prom", srv.URL, time.Second*5),
+		},
+		{
+			description: "series missing but check disabled, negative labels",
+			content: `
+# pint disable query/series(notfound)
+- record: foo
+  expr: count(notfound{job!="foo"}) == 0
+`,
+			checker: checks.NewSeriesCheck("prom", srv.URL, time.Second*5),
+		},
+		{
+			description: "series missing, disabled comment for labels",
+			content: `
+# pint disable query/series(notfound{job="foo"})
+- record: foo
+  expr: count(notfound) == 0
+`,
+			checker: checks.NewSeriesCheck("prom", srv.URL, time.Second*5),
+			problems: []checks.Problem{
+				{
+					Fragment: `notfound`,
+					Lines:    []int{4},
+					Reporter: "query/series",
+					Text:     `query using prom completed without any results for notfound`,
+					Severity: checks.Warning,
+				},
+			},
+		},
 	}
 	runTests(t, testCases)
 }