e2e prometheus: Add metallb test to check alerts

Signed-off-by: Suraj Deshmukh <suraj@kinvolk.io>

test/monitoring/component-alerts_test.go

@@ -0,0 +1,109 @@
+// Copyright 2020 The Lokomotive Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build aws packet
+// +build poste2e
+
+package monitoring
+
+import (
+	"context"
+	"fmt"
+	"reflect"
+	"testing"
+	"time"
+
+	testutil "github.com/kinvolk/lokomotive/test/components/util"
+
+	"github.com/prometheus/client_golang/api"
+	v1 "github.com/prometheus/client_golang/api/prometheus/v1"
+)
+
+// nolint:funlen
+func TestComponentAlerts(t *testing.T) {
+	const prometheusPodPort = 9090
+
+	p := &testutil.PortForwardInfo{
+		PodName:   "prometheus-prometheus-operator-prometheus-0",
+		Namespace: "monitoring",
+		PodPort:   prometheusPodPort,
+	}
+
+	p.PortForward(t)
+	defer p.CloseChan()
+	p.WaitUntilForwardingAvailable(t)
+
+	promClient, err := api.NewClient(api.Config{
+		Address: fmt.Sprintf("http://127.0.0.1:%d", p.LocalPort),
+	})
+	if err != nil {
+		t.Fatalf("Error creating client: %v", err)
+	}
+
+	v1api := v1.NewAPI(promClient)
+
+	const contextTimeout = 10
+
+	ctx, cancel := context.WithTimeout(context.Background(), contextTimeout*time.Second)
+	defer cancel()
+
+	result, err := v1api.Rules(ctx)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	alertTestCases := []struct {
+		Name   string
+		Alerts []string
+	}{
+		{
+			Name: "metallb-rules",
+			Alerts: []string{
+				"MetalLBNoBGPSession", "MetalLBConfigStale", "MetalLBControllerPodsAvailability",
+				"MetalLBSpeakerPodsAvailability",
+			},
+		},
+	}
+
+	// This map will store information from cluster so that it is easier to query it against the test cases
+	ruleGroups := make(map[string][]string, len(result.Groups))
+
+	for _, ruleGroup := range result.Groups {
+		rules := make([]string, 0)
+
+		for _, rule := range ruleGroup.Rules {
+			switch v := rule.(type) {
+			case v1.AlertingRule:
+				rules = append(rules, v.Name)
+			default:
+			}
+		}
+
+		ruleGroups[ruleGroup.Name] = rules
+	}
+
+	for _, alertTestCase := range alertTestCases {
+		alertTestCase := alertTestCase
+		t.Run(alertTestCase.Name, func(t *testing.T) {
+			rules, ok := ruleGroups[alertTestCase.Name]
+			if !ok {
+				t.Errorf("RuleGroup %q not found", alertTestCase.Name)
+				return
+			}
+			if !reflect.DeepEqual(rules, alertTestCase.Alerts) {
+				t.Errorf("Rules don't match. Expected: %#v and \ngot %#v", alertTestCase.Alerts, rules)
+			}
+		})
+	}
+}