feat: run unit tests for metrics rules

Added metrics unit tests file and a Makefile
target to run the tests.

Signed-off-by: Andrej Krejcir <[email protected]>

Makefile

@@ -84,7 +84,7 @@ endif
 all: manager
 
 .PHONY: unittest
-unittest: generate lint fmt vet manifests
+unittest: generate lint fmt vet manifests metrics-rules-test
 	go test -v -coverprofile cover.out $(SRC_PATHS_TESTS)
 	cd api && go test -v ./...
 
@@ -325,3 +325,22 @@ lint:
 .PHONY: lint-metrics
 lint-metrics:
 	./hack/prom_metric_linter.sh  --operator-name="kubevirt" --sub-operator-name="ssp"
+
+PROMTOOL ?= $(LOCALBIN)/promtool
+PROMTOOL_VERSION ?= 2.44.0
+
+.PHONY: promtool
+promtool: $(PROMTOOL)
+$(PROMTOOL): $(LOCALBIN)
+	test -s $(PROMTOOL) || curl -sSfL "https://github.com/prometheus/prometheus/releases/download/v$(PROMTOOL_VERSION)/prometheus-$(PROMTOOL_VERSION).linux-amd64.tar.gz" | \
+ 		tar xvzf - --directory=$(LOCALBIN) "prometheus-$(PROMTOOL_VERSION).linux-amd64"/promtool --strip-components=1
+
+METRIC_RULES_WRITER ?= $(LOCALBIN)/metrics-rules-writer
+
+.PHONY: build-metric-rules-writer
+build-metric-rules-writer: $(LOCALBIN)
+	go build -o $(METRIC_RULES_WRITER) tools/test-rules-writer/test_rules_writer.go
+
+.PHONY: metrics-rules-test
+metrics-rules-test: build-metric-rules-writer promtool
+	./hack/metrics-rules-test.sh $(METRIC_RULES_WRITER) "./pkg/monitoring/rules/rules-tests.yaml"

hack/metrics-rules-test.sh

@@ -0,0 +1,32 @@
+#!/usr/bin/env bash
+
+readonly PROMTOOL="$(dirname "$0")/../bin/promtool"
+
+function cleanup() {
+    local cleanup_dir="${1:?}"
+    rm -rf "${cleanup_dir}"
+}
+
+function main() {
+    local prom_spec_dumper="${1:?}"
+    local tests_file="${2:?}"
+    local temp_dir
+
+    temp_dir="$(mktemp --tmpdir --directory metrics_test_dir.XXXXX)"
+    trap "cleanup ${temp_dir}" RETURN EXIT INT
+
+    local rules_file="${temp_dir}/rules.json"
+    local tests_copy="${temp_dir}/rules-test.yaml"
+
+    "${prom_spec_dumper}" > "${rules_file}"
+    cp "${tests_file}" "${tests_copy}"
+
+    echo "INFO: Rules file content:"
+    cat "${rules_file}"
+    echo
+
+    ${PROMTOOL} check rules "${rules_file}"
+    ${PROMTOOL} test rules "${tests_copy}"
+}
+
+main "$@"

pkg/monitoring/rules/rules-tests.yaml

@@ -0,0 +1,26 @@
+# Unit tests for the prometheus rules
+rule_files:
+  - rules.json
+
+tests:
+  - interval: "1m"
+    input_series:
+      - series: 'up{pod="ssp-operator-12345"}'
+        values: '0x5 1'
+
+    alert_rule_test:
+      - eval_time: "5m"
+        alertname: "SSPDown"
+        exp_alerts:
+          - exp_annotations:
+              summary: "All SSP operator pods are down."
+              runbook_url: "test-runbook:SSPDown"
+            exp_labels:
+              severity: "critical"
+              operator_health_impact: "critical"
+              kubernetes_operator_part_of: "kubevirt"
+              kubernetes_operator_component: "ssp-operator"
+
+      - eval_time: "6m"
+        alertname: "SSPDown"
+        exp_alerts: []

tools/test-rules-writer/test_rules_writer.go

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+
+	promv1 "github.com/prometheus-operator/prometheus-operator/pkg/apis/monitoring/v1"
+
+	"kubevirt.io/ssp-operator/pkg/monitoring/rules"
+)
+
+func main() {
+	const runbookTemplate = "test-runbook:%s"
+
+	allRules := append(rules.RecordRules(), rules.AlertRules(runbookTemplate)...)
+
+	spec := promv1.PrometheusRuleSpec{
+		Groups: []promv1.RuleGroup{{
+			Name:  "test.rules",
+			Rules: allRules,
+		}},
+	}
+
+	encoder := json.NewEncoder(os.Stdout)
+	encoder.SetIndent("", "  ")
+	err := encoder.Encode(spec)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error encoding prometheus spec: %v", err)
+		os.Exit(1)
+	}
+}