e2e prometheus: Add metallb test to check alerts

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

test/monitoring/components_alerts_test.go

@@ -0,0 +1,120 @@
+// 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"
+
+	v1 "github.com/prometheus/client_golang/api/prometheus/v1"
+	"k8s.io/apimachinery/pkg/util/wait"
+
+	testutil "github.com/kinvolk/lokomotive/test/components/util"
+)
+
+const (
+	retryInterval  = time.Second * 5
+	timeout        = time.Minute * 9
+	contextTimeout = 10
+)
+
+type alertTestCase struct {
+	ComponentName string
+	RuleGroup     string
+	platforms     []testutil.Platform
+	Alerts        []string
+}
+
+//nolint:funlen
+func testComponentAlerts(t *testing.T, v1api v1.API) {
+	alertTestCases := []alertTestCase{
+		{
+			ComponentName: "metallb",
+			RuleGroup:     "metallb-rules",
+			platforms:     []testutil.Platform{testutil.PlatformPacket},
+			Alerts: []string{
+				"MetalLBNoBGPSession", "MetalLBConfigStale", "MetalLBControllerPodsAvailability",
+				"MetalLBSpeakerPodsAvailability",
+			},
+		},
+	}
+
+	for _, tc := range alertTestCases {
+		tc := tc
+		t.Run(tc.ComponentName, func(t *testing.T) {
+			t.Parallel()
+
+			if !testutil.IsPlatformSupported(t, tc.platforms) {
+				t.Skip()
+			}
+
+			if err := wait.PollImmediate(retryInterval, timeout,
+				getComponentAlertRetryFunc(t, v1api, tc)); err != nil {
+				t.Fatalf("%v", err)
+			}
+		})
+	}
+}
+
+func getComponentAlertRetryFunc(t *testing.T, v1api v1.API, tc alertTestCase) func() (done bool, err error) {
+	return func() (done bool, err error) {
+		ctx, cancel := context.WithTimeout(context.Background(), contextTimeout*time.Second)
+		defer cancel()
+
+		result, err := v1api.Rules(ctx)
+		if err != nil {
+			return false, fmt.Errorf("error listing rules: %v", err)
+		}
+
+		// This map will store information from cluster so that it is easier to search 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
+		}
+
+		rules, ok := ruleGroups[tc.RuleGroup]
+		if !ok {
+			// We don't return error here and just log it here because there is a
+			// possibility that the prometheus has not reconciled and we need to just return
+			// false i.e. not done and try again.
+			t.Logf("error: RuleGroup %q not found. Retrying...", tc.RuleGroup)
+			return false, nil
+		}
+
+		if !reflect.DeepEqual(rules, tc.Alerts) {
+			return false, fmt.Errorf("Rules don't match. Expected: %#v and \ngot %#v", tc.Alerts, rules)
+		}
+
+		return true, nil
+	}
+}