Echo microservoce using websocket

echo-websocket/.gitignore

@@ -0,0 +1 @@
+node_modules

echo-websocket/Dockerfile

@@ -0,0 +1,9 @@
+FROM node:alpine
+
+ENV DEBUG=*
+
+WORKDIR /src
+COPY . .
+RUN npm install
+
+CMD npm start

echo-websocket/index.js

@@ -0,0 +1,61 @@
+const ioFogClient = require('@iofog/nodejs-sdk')
+const WebSocketServer = require('ws').Server
+
+let port, wss
+ioFogClient.init('iofog', 54321, null, main)
+
+async function fetchConfig() {
+  const configRequest = () => new Promise((resolve, reject) => {
+    ioFogClient.getConfig({
+      'onBadRequest': reject,
+      'onError': reject,
+      'onNewConfig': resolve
+    })
+  })
+
+  try {
+    const config = await configRequest()
+    newPort = config.port || 8080
+    if (newPort !== port) {
+      if (wss) {
+        wss.clients.forEach(ws => ws.close())
+      }
+
+      port = newPort
+      wss = new WebSocketServer({ port })
+
+      console.log(`listening on port: ${port}`)
+
+      wss.on('connection', (ws) => {
+        console.log('new client connected!')
+        ws.send('connected!')
+        ws.on('message', (message) => {
+          console.log(message)
+          ws.send('echo: ' + message)
+        })
+      })
+
+      wss.on('close', () => {
+        console.log('disconnected');
+      })
+    }
+  } catch (e) {
+    console.error(e)
+    process.exit(1)
+  }
+
+}
+
+async function main() {
+  await fetchConfig()
+
+  ioFogClient.wsControlConnection({
+    'onNewConfigSignal': async () => {
+      await fetchConfig()
+    },
+    'onError': (error) => {
+      console.error('There was an error with Control WebSocket connection to ioFog: ', error)
+      process.exit(1)
+    }
+  })
+}

echo-websocket/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "echo-websocket",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "start": "node index.js"
+  },
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "@iofog/nodejs-sdk": "1.3.0",
+    "ws": "7.2.1"
+  }
+}