From bdd23c19b0da9f2ed21b6df2b5329556b791de50 Mon Sep 17 00:00:00 2001
From: Andrej Krejcir <akrejcir@redhat.com>
Date: Fri, 19 Jan 2024 12:46:28 +0100
Subject: [PATCH] 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 <akrejcir@redhat.com>
---
 Makefile                                     | 13 ++++-
 hack/metrics-rules-test.sh                   | 52 ++++++++++++++++++++
 pkg/monitoring/rules/rules-tests.yaml        | 26 ++++++++++
 tools/test-rules-writer/test_rules_writer.go | 32 ++++++++++++
 4 files changed, 122 insertions(+), 1 deletion(-)
 create mode 100755 hack/metrics-rules-test.sh
 create mode 100644 pkg/monitoring/rules/rules-tests.yaml
 create mode 100644 tools/test-rules-writer/test_rules_writer.go

diff --git a/Makefile b/Makefile
index 2f3719a9d..5c86cb056 100644
--- a/Makefile
+++ b/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 +325,14 @@ lint:
 .PHONY: lint-metrics
 lint-metrics:
 	./hack/prom_metric_linter.sh  --operator-name="kubevirt" --sub-operator-name="ssp"
+
+
+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
+	./hack/metrics-rules-test.sh $(METRIC_RULES_WRITER) "./pkg/monitoring/rules/rules-tests.yaml"
diff --git a/hack/metrics-rules-test.sh b/hack/metrics-rules-test.sh
new file mode 100755
index 000000000..2ba360ea7
--- /dev/null
+++ b/hack/metrics-rules-test.sh
@@ -0,0 +1,52 @@
+#!/usr/bin/env bash
+
+source $(dirname "$0")/config.sh
+
+readonly PROM_IMAGE="quay.io/prometheus/prometheus:v2.44.0"
+
+function cleanup() {
+    local cleanup_files=("${@:?}")
+
+    for file in "${cleanup_files[@]}"; do
+        rm -f "$file"
+    done
+}
+
+function lint() {
+    local target_file="${1:?}"
+
+    ${KUBEVIRT_CRI} run --rm --entrypoint=/bin/promtool \
+        -v "$target_file":/tmp/rules.verify:ro,Z "$PROM_IMAGE" \
+        check rules /tmp/rules.verify
+}
+
+function unit_test() {
+    local target_file="${1:?}"
+    local tests_file="${2:?}"
+
+    ${KUBEVIRT_CRI} run --rm --entrypoint=/bin/promtool \
+        -v "$tests_file":/tmp/rules.test:ro,Z \
+        -v "$target_file":/tmp/rules.verify:ro,Z \
+        "$PROM_IMAGE" \
+        test rules /tmp/rules.test
+}
+
+function main() {
+    local prom_spec_dumper="${1:?}"
+    local tests_file="${2:?}"
+    local target_file
+
+    target_file="$(mktemp --tmpdir -u tmp.prom_rules.XXXXX)"
+    trap "cleanup $target_file" RETURN EXIT INT
+
+    "$prom_spec_dumper" > "$target_file"
+
+    echo "INFO: Rules file content:"
+    cat "$target_file"
+    echo
+
+    lint "$target_file"
+    unit_test "$target_file" "$tests_file"
+}
+
+main "$@"
diff --git a/pkg/monitoring/rules/rules-tests.yaml b/pkg/monitoring/rules/rules-tests.yaml
new file mode 100644
index 000000000..2a7144f5c
--- /dev/null
+++ b/pkg/monitoring/rules/rules-tests.yaml
@@ -0,0 +1,26 @@
+# Unit tests for the prometheus rules
+rule_files:
+  - /tmp/rules.verify
+
+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: []
diff --git a/tools/test-rules-writer/test_rules_writer.go b/tools/test-rules-writer/test_rules_writer.go
new file mode 100644
index 000000000..af5efd505
--- /dev/null
+++ b/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)
+		return
+	}
+}