Make backend responsible for reporting its own metrics

backend.go

@@ -101,9 +101,6 @@ type Backend interface {
 	// Status returns a string describing the current status, this can detail queue sizes or other attributes
 	Status() string
 
-	// Heartbeat is called every minute, it can be used by backends to log status to a dashboard such as librato
-	Heartbeat() error
-
 	// RedisPool returns the redisPool for this backend
 	RedisPool() *redis.Pool
 }

backends/rapidpro/backend.go

@@ -237,10 +237,33 @@
 	courier.RegisterFlusher(path.Join(b.config.SpoolDir, "statuses"), b.flushStatusFile)
 	courier.RegisterFlusher(path.Join(b.config.SpoolDir, "events"), b.flushChannelEventFile)
 
+	b.startMetricsReporter(time.Minute)
+
 	slog.Info("backend started", "comp", "backend", "state", "started")
 	return nil
 }
 
+func (b *backend) startMetricsReporter(interval time.Duration) {
+	b.waitGroup.Add(1)
+
+	go func() {
+		defer func() {
+			slog.Info("metrics reporter exiting")
+			b.waitGroup.Done()
+		}()
+
+		for {
+			select {
+			case <-b.stopChan:
+				b.reportMetrics()
+				return
+			case <-time.After(interval):
+				b.reportMetrics()
+			}
+		}
+	}()
+}
+
 // Stop stops our RapidPro backend, closing our db and redis connections
 func (b *backend) Stop() error {
 	// close our stop channel
@@ -741,7 +764,7 @@
 	return health.String()
 }
 
-func (b *backend) Heartbeat() error {
+func (b *backend) reportMetrics() error {
 	rc := b.rp.Get()
 	defer rc.Close()
 

backends/rapidpro/backend_test.go

@@ -766,10 +766,6 @@ func (ts *BackendTestSuite) TestHealth() {
 	ts.Equal(ts.b.Health(), "")
 }
 
-func (ts *BackendTestSuite) TestHeartbeat() {
-	ts.NoError(ts.b.Heartbeat())
-}
-
 func (ts *BackendTestSuite) TestCheckForDuplicate() {
 	rc := ts.b.rp.Get()
 	defer rc.Close()

server.go

@@ -129,25 +129,6 @@ func (s *server) Start() error {
 		}
 	}()
 
-	s.waitGroup.Add(1)
-
-	// start our heartbeat
-	go func() {
-		defer s.waitGroup.Done()
-
-		for !s.stopped {
-			select {
-			case <-s.stopChan:
-				return
-			case <-time.After(time.Minute):
-				err := s.backend.Heartbeat()
-				if err != nil {
-					slog.Error("error running backend heartbeat", "error", err)
-				}
-			}
-		}
-	}()
-
 	slog.Info(fmt.Sprintf("server listening on %d", s.config.Port),
 		"comp", "server",
 		"port", s.config.Port,

test/backend.go

@@ -375,11 +375,6 @@ func (mb *MockBackend) Status() string {
 	return "ALL GOOD"
 }
 
-// Heartbeat is a noop for our mock backend
-func (mb *MockBackend) Heartbeat() error {
-	return nil
-}
-
 // RedisPool returns the redisPool for this backend
 func (mb *MockBackend) RedisPool() *redis.Pool {
 	return mb.redisPool