Add support for handling http2 GOAWAY messages and set http2 ping interval (#7)

* Add ping interval to native http2 implementation

* Gracefully destroy http2stream on GOAWAY frame

Author: funkenstrahlen

lib/client.js

@@ -19,6 +19,16 @@ module.exports = function (dependencies) {
 
   function Client (options) {
     this.config = config(options);
+    this.healthCheckInterval = setInterval(() => {
+         if (this.session && !this.session.destroyed) {
+             this.session.ping((error, duration) => {
+                 if (error) {
+                     logger("No Ping response after " + duration + " ms");
+                 }
+                 logger("Ping response after " + duration + " ms");
+             })
+         }
+     }, this.config.heartBeat).unref();
   }
 
   Client.prototype.write = function write (notification, device, count) {
@@ -43,6 +53,16 @@ module.exports = function (dependencies) {
         }
       });
 
+      this.session.on("goaway", (errorCode, lastStreamId, opaqueData) => {
+         logger(`GOAWAY received: (errorCode ${errorCode}, lastStreamId: ${lastStreamId}, opaqueData: ${opaqueData})`);
+         // gracefully stop accepting new streams
+         if (this.session && !this.session.destroyed) {
+           this.session.close(() => {
+             this.session.destroy();
+           });
+         }
+       });
+
       if (logger.enabled) {
         this.session.on("connect", () => {
           logger("Session connected");
@@ -53,9 +73,6 @@ module.exports = function (dependencies) {
         this.session.on("frameError", (frameType, errorCode, streamId) => {
           logger(`Frame error: (frameType: ${frameType}, errorCode ${errorCode}, streamId: ${streamId})`);
         });
-        this.session.on("goaway", (errorCode, lastStreamId, opaqueData) => {
-          logger(`GOAWAY received: (errorCode ${errorCode}, lastStreamId: ${lastStreamId}, opaqueData: ${opaqueData})`);
-        });
       }
     }
 
@@ -140,6 +157,9 @@ module.exports = function (dependencies) {
   };
 
   Client.prototype.shutdown = function shutdown(callback) {
+    if (this.healthCheckInterval) {
+      clearInterval(this.healthCheckInterval);
+    }
     if (this.session && !this.session.destroyed) {
       this.session.shutdown({graceful: true}, () => {
         this.session.destroy();