Don't fail when baseline query fails

cmd/pint/tests/0080_lint_online.txt

@@ -12,6 +12,7 @@ cmp stderr stderr.txt
 -- stderr.txt --
 level=info msg="Loading configuration file" path=.pint.hcl
 level=warn msg="No results for Prometheus uptime metric, you might have set uptime config option to a missing metric, please check your config" metric=prometheus_ready name=prom1
+level=warn msg="Using dummy Prometheus uptime metric results with no gaps" metric=prometheus_ready name=prom1
 rules/1.yml:2 Warning: http_errors_total[2d] selector is trying to query Prometheus for 2d worth of metrics, but prometheus "prom1" at http://127.0.0.1:7080 is configured to only keep 1d of metrics history (promql/range_query)
  2 |   expr: rate(http_errors_total[2d]) > 0
 

docs/changelog.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## v0.44.2
+
+### Fixed
+
+- Fixed a crash in `promql/series` check when Prometheus instance becomes
+  unavailable - #682.
+
 ## v0.44.1
 
 ### Fixed

internal/checks/promql_series.go

@@ -195,6 +195,27 @@ func (c SeriesCheck) Check(ctx context.Context, _ string, rule parser.Rule, entr
 				Str("metric", c.prom.UptimeMetric()).
 				Msg("No results for Prometheus uptime metric, you might have set uptime config option to a missing metric, please check your config")
 		}
+		if promUptime == nil || promUptime.Series.Ranges.Len() == 0 {
+			log.Warn().
+				Str("name", c.prom.Name()).
+				Str("metric", c.prom.UptimeMetric()).
+				Msg("Using dummy Prometheus uptime metric results with no gaps")
+			promUptime = &promapi.RangeQueryResult{
+				Series: promapi.SeriesTimeRanges{
+					From:  params.Start(),
+					Until: params.End(),
+					Step:  params.Step(),
+					Ranges: promapi.MetricTimeRanges{
+						{
+							Fingerprint: 0,
+							Labels:      labels.Labels{},
+							Start:       params.Start(),
+							End:         params.End(),
+						},
+					},
+				},
+			}
+		}
 
 		bareSelector := stripLabels(selector)
 

internal/checks/promql_series_test.go

@@ -1060,6 +1060,131 @@ func TestSeriesCheck(t *testing.T) {
 				},
 			},
 		},
+		{
+			description: "#3 metric present once with labels, failed baseline query",
+			content:     "- record: foo\n  expr: sum(found{job=\"abc\", cluster=\"dev\"})\n",
+			checker:     newSeriesCheck,
+			prometheus:  newSimpleProm,
+			problems: func(uri string) []checks.Problem {
+				return []checks.Problem{
+					{
+						Fragment: `found`,
+						Lines:    []int{2},
+						Reporter: checks.SeriesCheckName,
+						Text:     seriesSometimesText("prom", uri, `found`, "1w", "1d5m"),
+						Severity: checks.Warning,
+					},
+				}
+			},
+			mocks: []*prometheusMock{
+				{
+					conds: []requestCondition{
+						requireQueryPath,
+						formCond{key: "query", value: `count(found{cluster="dev",job="abc"})`},
+					},
+					resp: respondWithEmptyVector(),
+				},
+				{
+					conds: []requestCondition{
+						requireRangeQueryPath,
+						formCond{key: "query", value: `count(found)`},
+					},
+					resp: matrixResponse{
+						samples: []*model.SampleStream{
+							generateSampleStream(
+								map[string]string{},
+								time.Now().Add(time.Hour*24*-5),
+								time.Now().Add(time.Hour*24*-4),
+								time.Minute*5,
+							),
+						},
+					},
+				},
+				{
+					conds: []requestCondition{
+						requireRangeQueryPath,
+						formCond{key: "query", value: `count(found{job="abc"})`},
+					},
+					resp: matrixResponse{
+						samples: []*model.SampleStream{
+							generateSampleStream(
+								map[string]string{},
+								time.Now().Add(time.Hour*24*-5),
+								time.Now().Add(time.Hour*24*-5),
+								time.Minute*5,
+							),
+						},
+					},
+				},
+				{
+					conds: []requestCondition{
+						requireRangeQueryPath,
+						formCond{key: "query", value: `count(found{cluster="dev"})`},
+					},
+					resp: matrixResponse{
+						samples: []*model.SampleStream{
+							generateSampleStream(
+								map[string]string{},
+								time.Now().Add(time.Hour*24*-5),
+								time.Now().Add(time.Hour*24*-5).Add(time.Minute*10),
+								time.Minute*5,
+							),
+						},
+					},
+				},
+				{
+					conds: []requestCondition{
+						requireRangeQueryPath,
+						formCond{key: "query", value: `absent(found{job=~".+"})`},
+					},
+					resp: matrixResponse{
+						samples: []*model.SampleStream{
+							generateSampleStream(
+								map[string]string{},
+								time.Now().Add(time.Hour*24*-7),
+								time.Now().Add(time.Hour*24*-5).Add(time.Minute*-10),
+								time.Minute*5,
+							),
+							generateSampleStream(
+								map[string]string{},
+								time.Now().Add(time.Hour*24*-5).Add(time.Minute*5),
+								time.Now(),
+								time.Minute*5,
+							),
+						},
+					},
+				},
+				{
+					conds: []requestCondition{
+						requireRangeQueryPath,
+						formCond{key: "query", value: `absent(found{cluster=~".+"})`},
+					},
+					resp: matrixResponse{
+						samples: []*model.SampleStream{
+							generateSampleStream(
+								map[string]string{},
+								time.Now().Add(time.Hour*24*-7),
+								time.Now().Add(time.Hour*24*-5).Add(time.Minute*-10),
+								time.Minute*5,
+							),
+							generateSampleStream(
+								map[string]string{},
+								time.Now().Add(time.Hour*24*-5).Add(time.Minute*10),
+								time.Now(),
+								time.Minute*5,
+							),
+						},
+					},
+				},
+				{
+					conds: []requestCondition{
+						requireRangeQueryPath,
+						formCond{key: "query", value: "count(up)"},
+					},
+					resp: respondWithInternalError(),
+				},
+			},
+		},
 		{
 			description: "#4 metric was present but disappeared 50m ago",
 			content:     "- record: foo\n  expr: sum(found{job=\"foo\", instance=\"bar\"})\n",
@@ -3024,6 +3149,46 @@ func TestSeriesCheck(t *testing.T) {
 				},
 			},
 		},
+		{
+			description: "series missing, failed baseline query",
+			content:     "- record: foo\n  expr: count(notfound) == 0\n",
+			checker:     newSeriesCheck,
+			prometheus:  newSimpleProm,
+			problems: func(uri string) []checks.Problem {
+				return []checks.Problem{
+					{
+						Fragment: `notfound`,
+						Lines:    []int{2},
+						Reporter: checks.SeriesCheckName,
+						Text:     noSeriesText("prom", uri, "notfound", "1w"),
+						Severity: checks.Bug,
+					},
+				}
+			},
+			mocks: []*prometheusMock{
+				{
+					conds: []requestCondition{
+						requireQueryPath,
+						formCond{key: "query", value: `count(notfound)`},
+					},
+					resp: respondWithEmptyVector(),
+				},
+				{
+					conds: []requestCondition{
+						requireRangeQueryPath,
+						formCond{key: "query", value: `count(notfound)`},
+					},
+					resp: respondWithEmptyMatrix(),
+				},
+				{
+					conds: []requestCondition{
+						requireRangeQueryPath,
+						formCond{key: "query", value: "count(up)"},
+					},
+					resp: respondWithInternalError(),
+				},
+			},
+		},
 	}
 	runTests(t, testCases)
 }