WIP: Create node app to act as proxy in front of kernel gateway.

Ref jupyter#135

(c) Copyright IBM Corp. 2015

node-deployed-dashboard/.bowerrc

@@ -0,0 +1,4 @@
+{
+  "directory": "public/components",
+  "json": "bower.json"
+}

node-deployed-dashboard/.editorconfig

@@ -0,0 +1,10 @@
+# http://editorconfig.org
+root = true
+
+[*]
+indent_style = space
+indent_size = 2
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true

node-deployed-dashboard/.gitignore

@@ -0,0 +1,3 @@
+node_modules/
+public/components
+.sass-cache

node-deployed-dashboard/app.js

@@ -0,0 +1,82 @@
+
+
+var express = require('express');
+var path = require('path');
+var favicon = require('serve-favicon');
+var logger = require('morgan');
+var cookieParser = require('cookie-parser');
+var bodyParser = require('body-parser');
+var exphbs  = require('express-handlebars');
+var config = require('./config/config');
+
+var routes = require('./routes/index');
+var apiRoutes = require('./routes/api');
+// var users = require('./routes/user');
+
+var kernelProxy = require('./app/kernel-proxy');
+
+var app = express();
+
+var env = process.env.NODE_ENV || 'development';
+app.locals.ENV = env;
+app.locals.ENV_DEVELOPMENT = env == 'development';
+
+// view engine setup
+
+app.engine('handlebars', exphbs({
+  defaultLayout: 'main',
+  partialsDir: ['views/partials/']
+}));
+app.set('views', path.join(__dirname, 'views'));
+app.set('view engine', 'handlebars');
+
+// app.use(favicon(__dirname + '/public/img/favicon.ico'));
+app.use(logger('dev'));
+app.use(bodyParser.json());
+app.use(bodyParser.urlencoded({
+  extended: true
+}));
+app.use(cookieParser());
+app.use(express.static(path.join(__dirname, 'public')));
+
+app.use('/', routes);
+app.use('/api', apiRoutes);
+// app.use('/users', users);
+
+/// catch 404 and forward to error handler
+app.use(function(req, res, next) {
+    var err = new Error('Not Found');
+    err.status = 404;
+    next(err);
+});
+
+/// error handlers
+
+// development error handler
+// will print stacktrace
+
+if (app.get('env') === 'development') {
+    app.use(function(err, req, res, next) {
+        res.status(err.status || 500);
+        res.render('error', {
+            message: err.message,
+            error: err,
+            title: 'error'
+        });
+    });
+}
+
+// production error handler
+// no stacktraces leaked to user
+app.use(function(err, req, res, next) {
+    res.status(err.status || 500);
+    res.render('error', {
+        message: err.message,
+        error: {},
+        title: 'error'
+    });
+});
+
+// kernelProxy.init(config);
+
+module.exports = app;

node-deployed-dashboard/app/kernel-proxy.js

@@ -0,0 +1,128 @@
+var Services = require('jupyter-js-services');
+var request = require('request');
+var Promise = require('es6-promise').Promise;
+var XMLHttpRequest = require('xmlhttprequest').XMLHttpRequest;
+var WebSocket = require('ws');
+
+global.XMLHttpRequest = XMLHttpRequest;
+global.WebSocket = WebSocket;
+
+function init(config) {
+    var baseUrl = config.kernelGatewayUrl;
+    baseUrl += (baseUrl[baseUrl.length - 1] === '/' ? '' : '/'); // ensure it ends in '/'
+
+    // check if we need to spawn a new container or use existing one
+    // check for a previous container, which we can reuse
+    // var containerUrl = localStorage.getItem(CONTAINER_URL);
+    // TODO get CONTAINER_URL from request
+    var containerUrl = null;
+
+    // TODO return CONTAINER_URL to the client
+    return checkExistingContainer(containerUrl)
+        .then(function(containerExists) {
+            if (!containerExists) {
+                console.log('spawning! [', baseUrl, ']');
+                return callSpawn(baseUrl);
+            } else {
+                return { url: containerUrl };
+            }
+        })
+        .then(function(data) {
+            var kernelOptions = {
+                baseUrl: data.url,
+                wsUrl: data.url.replace(/^http/, 'ws'),
+                name: 'python3'
+            };
+            console.log('starting new kernel at', data.url);
+            Services.startNewKernel(kernelOptions)
+                .then(function(kernel) {
+                    setupKernel(kernel);
+                    return true;
+                }).catch(function(e) {
+                    console.error('Failed to create session/kernel:', e);
+                });
+        });
+}
+
+// generates a session URL containing a unique id
+function generateSessionUrl() {
+    // TODO get path from request
+    return window.location.pathname + '#' + generateId();
+}
+
+// adapted from http://guid.us/GUID/JavaScript
+function generateId() {
+    return (((1+Math.random())*0x100000000)|0).toString(16).substring(1);
+}
+
+// register event handlers on a new kernel
+function setupKernel(_kernel) {
+    console.log('> setupKernel');
+    kernel = _kernel;
+
+    kernel.commOpened.connect(function(_kernel, commMsg) {
+        console.log('> commOpened');
+        var comm = kernel.connectToComm(commMsg.target_name, commMsg.comm_id);
+    });
+}
+
+// Spawn a new kernel container. Returns promise to container URL.
+function callSpawn(baseUrl) {
+    return new Promise(function(resolve, reject) {
+        request.post({
+            url: baseUrl + 'api/spawn/',
+            json: true
+            // body: { image_name: 'jupyter/notebook' }, // TODO remove if not necessary
+        }, function(error, response, body) {
+            // console.log(response);
+            if (!error && response.statusCode >= 200 && response.statusCode < 300) {
+                console.log(body);
+                if (body.status === 'full') {
+                    reject('tmpnb server is full');
+                    // throw new Error('tmpnb server is full');
+                } else {
+                    // test if we have a full URL (new tmpnb) or partial (old tmpnb)
+                    if (!/^http/.test(body.url)) {
+                        body.url = baseUrl + body.url;
+                    }
+                    resolve(body);
+                }
+            } else if (error) {
+                reject('error spawning tmpnb container' + error);
+                // throw new Error('error spawning tmpnb container', error);
+            }
+        });
+    });
+}
+
+// Check if container at URL is valid. Returns promise to boolean value.
+function checkExistingContainer(url) {
+    return new Promise(function(resolve, reject) {
+        if (!url) {
+            return resolve(false); // There is no existing container
+        }
+
+        url += (url[url.length - 1] === '/' ? '' : '/'); // ensure it ends in '/'
+
+        request.get(url + 'api/kernels', function(error, response, body) {
+            if (!error && response.statusCode == 200) {
+                try {
+                    var data = JSON.parse(body);
+                    resolve(true);
+                } catch(e) {
+                    // JSON conversion failed, most likely because response is HTML text telling us
+                    // that the container doesn't exist. Therefore, fail.
+                    resolve(false);
+                    // TODO let client know to clear local storage for CONTAINER_URL
+                }
+            } else if (error) {
+                resolve(false);
+                // TODO let client know to clear local storage for CONTAINER_URL
+            }
+        });
+    });
+}
+
+module.exports = {
+    init: init
+};

node-deployed-dashboard/bin/www

@@ -0,0 +1,8 @@
+#!/usr/bin/env node
+var app = require('../app');
+
+app.set('port', process.env.PORT || 3000);
+
+var server = app.listen(app.get('port'), function() {
+  console.log('Express server listening on port ' + server.address().port);
+});

node-deployed-dashboard/bower.json

@@ -0,0 +1,9 @@
+{
+  "name": "node-deployed-dashboard",
+  "version": "0.0.1",
+  "ignore": [
+    "**/.*",
+    "node_modules",
+    "components"
+  ]
+}

node-deployed-dashboard/config/config.js

@@ -0,0 +1,7 @@
+/**
+ * Copy to `config.js` and enter correct values.
+ */
+
+module.exports = {
+    kernelGatewayUrl: 'https://tmpnb-urth-demo.cloudet.xyz/'
+};

node-deployed-dashboard/config/config.js.template

@@ -0,0 +1,7 @@
+/**
+ * Copy to `config.js` and enter correct values.
+ */
+
+module.exports = {
+    kernelGatewayUrl: ''
+};