Upgrade node environment to Node.js 7.6.0+ (#151)

Upgrades the node environment to NodeJS 7.6.0.  Functions can now use async/await and promises; they can return a promise instead of using a callback.  The change preserves compatibility with the callback style.  

* Upgrade node environment to Node.js 7.6.0+

* Bump package version

* Preserve compatibility for callbacks

* Cleanup

* Re-add hello callback example

* Make sure not returning won't blow everything up

* Update stock example with request promise

examples/nodejs/hello-callback.js

@@ -0,0 +1,4 @@
+
+module.exports = function(context, callback) {
+    callback(200, "Hello, world!\n");
+}

examples/nodejs/hello.js

@@ -1,4 +1,7 @@
 
-module.exports = function(context, callback) {
-    callback(200, "Hello, world!\n");
+module.exports = async function(context) {
+    return {
+        status: 200,
+        body: "Hello, world!\n"
+    };
 }

examples/nodejs/kubeEventsSlack.js

@@ -23,7 +23,7 @@ function upcaseFirst(s) {
     return s.charAt(0).toUpperCase() + s.slice(1).toLowerCase();
 }
 
-function sendSlackMessage(msg, cb) {
+async function sendSlackMessage(msg) {
     let postData = `{"text": "${msg}"}`;
     let options = {
         hostname: "hooks.slack.com",
@@ -33,17 +33,20 @@ function sendSlackMessage(msg, cb) {
             "Content-Type": "application/json"
         }
     };
-    let req = https.request(options, function(res) {
-        console.log(`slack request status = ${res.statusCode}`);
-        cb();
+
+    return new Promise(function(resolve, reject) {
+        let req = https.request(options, function(res) {
+            console.log(`slack request status = ${res.statusCode}`);
+            return resolve();
+        });
+        req.write(postData);
+        req.end();
     });
-    req.write(postData);
-    req.end();
 }
 
-module.exports = function(context, callback) {
+module.exports = async function(context) {
     console.log(context.request.headers);
-    
+
     let obj = context.request.body;
     let version = obj.metadata.resourceVersion;
     let eventType = context.request.get('X-Kubernetes-Event-Type');
@@ -54,10 +57,11 @@ module.exports = function(context, callback) {
 
     if (eventType == 'DELETED' || eventType == 'ADDED') {
         console.log("sending event to slack")
-        sendSlackMessage(msg, function() {
-            callback(200, "");
-        });
-    } else {
-        callback(200, "");
+        await sendSlackMessage(msg);
+    }
+
+    return {
+        status: 200,
+        body: ""
     }
 }

examples/nodejs/stock.js

@@ -1,31 +1,37 @@
 'use strict';
 
-var http = require('http');
+const rp = require('request-promise-native');
 
-module.exports = function (context, callback) {    
-    let body = context.request.body;
-    console.log(`body text: ${body['text']}`);
+module.exports = async function (context) {
+    const body = context.request.body;
+    const symbol = body.symbol
 
-    var symbol = body['text'].split(' ')[1];
+    console.log(`Got symbol: ${symbol}`);
 
-    http.get({
-        host: 'finance.google.com',
-        path: `/finance/info?q=NYSE:${symbol}`
-    }, function(response) {
-        var resp = '';
-        response.on('data', function(d) {
-            resp += d;
-        });
-        response.on('end', function() {
-
-            try {
-                var parsed = JSON.parse(resp.slice(3));
-                var lastTrade = parsed[0]['l_cur']
-                callback(200, `{ "text": "${symbol} last traded at ${lastTrade}" }`);
-            } catch (e) {
-                callback(200, `{ "text": "Error (invalid NYSE symbol?)" }`);
+    if (!symbol) {
+        return {
+            status: 400,
+            body: {
+                text: 'You must provide a stock symbol.'
             }
-        });
-    });
+        };
+    }
 
+    try {
+        const response = await rp(`http://finance.google.com/finance/info?q=NYSE:${symbol}`);
+        const parsed = JSON.parse(response.slice(3));
+        const lastTrade = parsed[0]['l_cur'];
+        return {
+            status: 200,
+            body: {
+                text: `${symbol} last traded at ${lastTrade}`
+            }
+        };
+    } catch (e) {
+        console.error(e);
+        return {
+            status: 500,
+            body: e
+        };
+    }
 }