Return an error if the logs api is not supported (#64)

Author: estolfo

apm-lambda-extension/logsapi/client.go

@@ -154,6 +154,7 @@ func (c *Client) Subscribe(types []EventType, bufferingCfg BufferingCfg, destina
 
 	if resp.StatusCode == http.StatusAccepted {
 		log.Println("Logs API is not supported. Is this extension running in a local sandbox?")
+		return nil, errors.Errorf("Logs API is not supported in this environment")
 	} else if resp.StatusCode != http.StatusOK {
 		body, err := ioutil.ReadAll(resp.Body)
 		if err != nil {

apm-lambda-extension/main.go

@@ -65,22 +65,26 @@ func main() {
 
 	extension.NewHttpServer(dataChannel, config)
 
+	// Make channel for collecting logs and create a HTTP server to listen for them
+	logsChannel := make(chan logsapi.LogEvent)
+
 	// Subscribe to the Logs API
-	logsapi.Subscribe(
+	err = logsapi.Subscribe(
 		extensionClient.ExtensionID,
 		[]logsapi.EventType{logsapi.Platform})
-
-	// Make channel for collecting logs and create a HTTP server to listen for them
-	logsChannel := make(chan logsapi.LogEvent)
-	logsAPIListener, err := logsapi.NewLogsAPIHttpListener(logsChannel)
 	if err != nil {
-		log.Printf("Error while creating Logs API listener: %v", err)
-	}
+		log.Printf("Could not subscribe to the logs API. Will instead flush APM data 100ms before the function deadline.")
+	} else {
+		logsAPIListener, err := logsapi.NewLogsAPIHttpListener(logsChannel)
+		if err != nil {
+			log.Printf("Error while creating Logs API listener: %v", err)
+		}
 
-	// Start the logs HTTP server
-	_, err = logsAPIListener.Start(logsapi.ListenOnAddress())
-	if err != nil {
-		log.Printf("Error while starting Logs API listener: %v", err)
+		// Start the logs HTTP server
+		_, err = logsAPIListener.Start(logsapi.ListenOnAddress())
+		if err != nil {
+			log.Printf("Error while starting Logs API listener: %v", err)
+		}
 	}
 
 	for {
@@ -170,7 +174,7 @@ func main() {
 
 			select {
 			case <-runtimeDone:
-				log.Println("Receive runtimeDone event signal")
+				log.Println("Received runtimeDone event signal")
 			case <-timer.C:
 				log.Println("Time expired waiting for runtimeDone event")
 			}