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

environments/nodejs/.gitignore

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

environments/nodejs/Dockerfile

@@ -1,6 +1,6 @@
 # A docker image for the func container.
 
-FROM node:4-onbuild
+FROM node:7-onbuild
 
 ADD server.js /usr/src/app/server.js
 

environments/nodejs/package.json

@@ -1,27 +1,26 @@
 {
-    "name": "fission-nodejs-runtime",
-    "version": "0.0.0",
-    "author": "Soam Vasani",
-    "contributors": [
-        {
-            "name": "Soam Vasani",
-            "email": "soamvasani@platform9.com"
-        }
-    ],
-    "description": "NodeJS run container for the fission framework",
-    "engines": {
-        "node": ">=4.2.2"
-    },
-    "dependencies": {
-        "express": "",
-        "minimist": "",
-        "body-parser": "",
-        "morgan": "",
-
-        "co": "~4.6.0",
-        "request": "",
-        "request-promise": "^1.0.2",
-        "mz": "~2.1.0",
-        "underscore": ">=1.8.3"
+  "name": "fission-nodejs-runtime",
+  "version": "0.1.0",
+  "author": "Soam Vasani",
+  "contributors": [
+    {
+      "name": "Soam Vasani",
+      "email": "soamvasani@platform9.com"
     }
+  ],
+  "description": "NodeJS run container for the fission framework",
+  "engines": {
+    "node": ">=7.6.0"
+  },
+  "dependencies": {
+    "body-parser": "",
+    "co": "~4.6.0",
+    "express": "",
+    "minimist": "",
+    "morgan": "",
+    "mz": "~2.1.0",
+    "request": "^2.81.0",
+    "request-promise-native": "^1.0.3",
+    "underscore": ">=1.8.3"
+  }
 }

environments/nodejs/server.js

@@ -75,11 +75,13 @@ app.all('/', function (req, res) {
         res.status(500).send("Generic container: no requests supported");
         return;
     }
+
     const context = {
         request: req,
         response: res
         // TODO: context should also have: URL template params, query string
     };
+
     function callback(status, body, headers) {
         if (!status)
             return;
@@ -90,18 +92,32 @@ app.all('/', function (req, res) {
         }
         res.status(status).send(body);
     }
-    try {
-        //
-        // Customizing the request context
-        //
-        // If you want to modify the context to add anything to it,
-        // you can do that here by adding properties to the context.
-        //
-        userFunction(context, callback);
-    } catch(e) {
-        console.log(`Function error: ${e}`);
-        callback(500, "Internal server error")
+
+    //
+    // Customizing the request context
+    //
+    // If you want to modify the context to add anything to it,
+    // you can do that here by adding properties to the context.
+    //
+
+    let functionProm;
+    if (userFunction.length === 1) { // One argument (context)
+        // Make sure their function returns a promise
+        Promise.resolve(userFunction(context)).then(function({ status, body, headers }) {
+            callback(status, body, headers);
+        }).catch(function(err) {
+            console.log(`Function error: ${e}`);
+            callback(500, "Internal server error");
+        });
+    } else { // 2 arguments (context, callback)
+        try {
+            userFunction(context, callback);
+        } catch (err) {
+            console.log(`Function error: ${e}`);
+            callback(500, "Internal server error");
+        }
     }
+
 });
 
 app.listen(argv.port);

environments/nodejs/test/test.js

@@ -1,6 +1,9 @@
-module.exports = function (context, callback) {
+module.exports = async function (context) {
     console.log("headers=", JSON.stringify(context.request.headers));
     console.log("body=", JSON.stringify(context.request.body));
 
-    callback(200, "Hello, world !\n");
+    return {
+        status: 200,
+        body: "Hello, world !\n"
+    };
 }