Rule component: Adding new API end point for rules and alerts in (#851)

* Adding new API end point for rules and alerts

* reusing methods in query api

* Adding unitest for rule API (similar to prometheus rule/alert API end point unitest)

* Adding SetCORS

* Removing comments

* Related to issue #850

benchmark/cmd/thanosbench/resources.go

@@ -12,6 +12,7 @@ import (
 	prom "github.com/prometheus/prometheus/config"
 	"gopkg.in/yaml.v2"
 	appsv1 "k8s.io/api/apps/v1"
+	"k8s.io/api/core/v1"
 	rbacv1 "k8s.io/api/rbac/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -207,7 +208,7 @@ func createPrometheus(opts *opts, name string, bucket string) *appsv1.StatefulSe
 		Name:      name,
 		Namespace: promNamespace,
 		Labels: map[string]string{
-			"app": name,
+			"app":                  name,
 			"thanos-gossip-member": "true",
 		},
 	}
@@ -370,7 +371,7 @@ func createThanosQuery(opts *opts) (*v1.Service, *v1.Pod) {
 		Name:      "thanos-query",
 		Namespace: thanosNamespace,
 		Labels: map[string]string{
-			"app": "thanos-query",
+			"app":                  "thanos-query",
 			"thanos-gossip-member": "true",
 		},
 	}

cmd/thanos/rule.go

@@ -10,6 +10,7 @@ import (
 	"net/url"
 	"os"
 	"os/signal"
+	"path"
 	"path/filepath"
 	"sort"
 	"strconv"
@@ -29,6 +30,7 @@ import (
 	"github.com/improbable-eng/thanos/pkg/extprom"
 	"github.com/improbable-eng/thanos/pkg/objstore/client"
 	"github.com/improbable-eng/thanos/pkg/promclient"
+	"github.com/improbable-eng/thanos/pkg/rule/api"
 	"github.com/improbable-eng/thanos/pkg/runutil"
 	"github.com/improbable-eng/thanos/pkg/shipper"
 	"github.com/improbable-eng/thanos/pkg/store"
@@ -565,6 +567,9 @@ func runRule(
 
 		ui.NewRuleUI(logger, mgr, alertQueryURL.String(), flagsMap).Register(router.WithPrefix(webRoutePrefix))
 
+		api := v1.NewAPI(logger, mgr)
+		api.Register(router.WithPrefix(path.Join(webRoutePrefix, "/api/v1")), tracer, logger)
+
 		mux := http.NewServeMux()
 		registerMetrics(mux, reg)
 		registerProfile(mux)