Fixes #78 | Process requests async

From now all events will be processed in background.
500 and 400 response codes should not appear for end
user. Instead they will get 202 Accepted.

README.md

@@ -119,6 +119,7 @@ consul-token           |                       | The Consul ACL token
 consul-tag             | `marathon`            | Common tag name added to every service registered in Consul, should be unique for every Marathon-cluster connected to Consul
 consul-timeout         | `3s`                  | Time limit for requests made by the Consul HTTP client. A Timeout of zero means no timeout
 listen                 | `:4000`               | Accept connections at this address
+events-queue-size      | `1000`                | Size of events queue
 log-level              | `info`                | Log level: panic, fatal, error, warn, info, or debug
 log-format             | `text`                | Log format: JSON, text
 log-file               |                       | Save logs to file (e.g.: `/var/log/marathon-consul.log`). If empty logs are published to STDERR
@@ -132,9 +133,10 @@ metrics-location       |                       | Graphite URL (used when metrics
 metrics-prefix         | `default`             | Metrics prefix (resolved to `<hostname>.<app_name>` by default)
 metrics-target         | `stdout`              | Metrics destination `stdout` or `graphite` (empty string disables metrics)
 sync-enabled           | `true`                | Enable Marathon-consul scheduled sync
+sync-force             | `false`               | Force leadership-independent Marathon-consul sync (run always)
 sync-interval          | `15m0s`               | Marathon-consul sync [interval](https://golang.org/pkg/time/#Duration) **Note:** While using file configuration intervals should be provided in *nanoseconds*
 sync-leader            | `<hostname>:8080`     | Marathon cluster-wide node name (defaults to `<hostname>:8080`), the sync will run only if the node is the current [Marathon-leader](https://mesosphere.github.io/marathon/docs/rest-api.html#get-v2-leader)
-sync-force             | `false`               | Force leadership-independent Marathon-consul sync (run always)
+workers-pool-size      |:`10`                  | Number of concurrent workers processing events
 
 
 ### Endpoints

config/config.go

@@ -12,14 +12,13 @@ import (
 	"github.com/allegro/marathon-consul/marathon"
 	"github.com/allegro/marathon-consul/metrics"
 	"github.com/allegro/marathon-consul/sync"
+	"github.com/allegro/marathon-consul/web"
 	flag "github.com/ogier/pflag"
 )
 
 type Config struct {
-	Consul consul.ConsulConfig
-	Web    struct {
-		Listen string
-	}
+	Consul   consul.ConsulConfig
+	Web      web.Config
 	Sync     sync.Config
 	Marathon marathon.Config
 	Metrics  metrics.Config
@@ -75,6 +74,8 @@ func (config *Config) parseFlags() {
 
 	// Web
 	flag.StringVar(&config.Web.Listen, "listen", ":4000", "accept connections at this address")
+	flag.IntVar(&config.Web.QueueSize, "events-queue-size", 1000, "size of events queue")
+	flag.IntVar(&config.Web.WorkersCount, "workers-pool-size", 10, "number of concurrent workers processing events")
 
 	// Sync
 	flag.BoolVar(&config.Sync.Enabled, "sync-enabled", true, "Enable Marathon-consul scheduled sync")

config/config_test.go

@@ -10,6 +10,7 @@ import (
 	"github.com/allegro/marathon-consul/marathon"
 	"github.com/allegro/marathon-consul/metrics"
 	"github.com/allegro/marathon-consul/sync"
+	"github.com/allegro/marathon-consul/web"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -99,7 +100,11 @@ func TestConfig_ShouldBeMergedWithFileDefaultsAndFlags(t *testing.T) {
 			RequestRetries:         5,
 			AgentFailuresTolerance: 3,
 		},
-		Web: struct{ Listen string }{Listen: ":4000"},
+		Web: web.Config{
+			Listen:       ":4000",
+			QueueSize:    1000,
+			WorkersCount: 10,
+		},
 		Sync: sync.Config{
 			Interval: 15 * time.Minute,
 			Enabled:  true,

debian/config.json

@@ -17,7 +17,9 @@
     "RequestRetries": 5
   },
   "Web": {
-    "Listen": ":4000"
+    "Listen": ":4000",
+    "QueueSize": 1000,
+    "WorkersCount": 10
   },
   "Sync": {
     "Enabled": true,

main.go

@@ -37,9 +37,12 @@ func main() {
 	sync := sync.New(config.Sync, remote, service)
 	go sync.StartSyncServicesJob()
 
+	handler, stop := web.NewHandler(config.Web, remote, service)
+	defer stop()
+
 	// set up routes
 	http.HandleFunc("/health", web.HealthHandler)
-	http.HandleFunc("/events", web.NewEventHandler(service, remote).Handle)
+	http.HandleFunc("/events", handler)
 
 	log.WithField("Port", config.Web.Listen).Info("Listening")
 	log.Fatal(http.ListenAndServe(config.Web.Listen, nil))

marathon/marathon_stub.go

@@ -7,36 +7,45 @@ import (
 )
 
 type MarathonerStub struct {
-	AppsStub  []*apps.App
-	AppStub   map[apps.AppId]*apps.App
-	TasksStub map[apps.AppId][]*apps.Task
-	leader    string
+	AppsStub     []*apps.App
+	AppStub      map[apps.AppId]*apps.App
+	TasksStub    map[apps.AppId][]*apps.Task
+	leader       string
+	interactions bool
 }
 
-func (m MarathonerStub) ConsulApps() ([]*apps.App, error) {
+func (m *MarathonerStub) ConsulApps() ([]*apps.App, error) {
+	m.interactions = true
 	return m.AppsStub, nil
 }
 
-func (m MarathonerStub) App(id apps.AppId) (*apps.App, error) {
+func (m *MarathonerStub) App(id apps.AppId) (*apps.App, error) {
+	m.interactions = true
 	if app, ok := m.AppStub[id]; ok {
 		return app, nil
 	} else {
 		return nil, fmt.Errorf("app not found")
 	}
 }
 
-func (m MarathonerStub) Tasks(appId apps.AppId) ([]*apps.Task, error) {
+func (m *MarathonerStub) Tasks(appId apps.AppId) ([]*apps.Task, error) {
+	m.interactions = true
 	if app, ok := m.TasksStub[appId]; ok {
 		return app, nil
 	} else {
 		return nil, fmt.Errorf("app not found")
 	}
 }
 
-func (m MarathonerStub) Leader() (string, error) {
+func (m *MarathonerStub) Leader() (string, error) {
+	m.interactions = true
 	return m.leader, nil
 }
 
+func (m MarathonerStub) Interactions() bool {
+	return m.interactions
+}
+
 func MarathonerStubWithLeaderForApps(leader string, args ...*apps.App) *MarathonerStub {
 	stub := MarathonerStubForApps(args...)
 	stub.leader = leader

marathon/marathon_stub_test.go

@@ -12,9 +12,12 @@ func TestMarathonStub(t *testing.T) {
 	t.Parallel()
 	// given
 	m := marathon.MarathonerStubWithLeaderForApps("some.host:1234", utils.ConsulApp("/test/app", 3))
+	// then
+	assert.False(t, m.Interactions())
 	// when
 	leader, _ := m.Leader()
 	// then
+	assert.True(t, m.Interactions())
 	assert.Equal(t, "some.host:1234", leader)
 	// when
 	apps, _ := m.ConsulApps()

web/config.go

@@ -0,0 +1,7 @@
+package web
+
+type Config struct {
+	Listen       string
+	QueueSize    int
+	WorkersCount int
+}