Add service for github authentication

app/controllers/auth.js

@@ -1,17 +1,36 @@
 const express = require("express");
 
+const config = require("../../config");
+const User = require("../models/user");
+const GitHub = require("../services/github");
+
 const router = express.Router();
 
 router.get("/logout", function(req, res) {
   // TODO
 });
 
 router.get("/login/github", function(req, res) {
-  // TODO
+  const github = new GitHub(config.githubClientId, config.githubClientSecret);
+  res.redirect(github.authorization_url("public_repo"));
 });
 
-router.get("/callback/github", function(req, res) {
-  // TODO
+router.get("/callback/github", async function(req, res) {
+  if (!req.query.code) {
+    return res.render("500");
+  }
+
+  // Fetch user from GitHub OAuth and store in session
+  const github = new GitHub(config.githubClientId, config.githubClientSecret);
+  const access_token = await github.get_token(req.query.code);
+
+  if (!access_token) {
+    return res.render("404");
+  }
+
+  const user = User.find_or_create_from_token(access_token);
+
+  return res.redirect("/");
 });
 
 module.exports = router;

app/index.js

@@ -1,25 +1,35 @@
 const express = require("express");
-const bodyParser = require("body-parser");
 const compression = require("compression");
 const handlebars = require("express-handlebars");
+const logger = require("morgan");
 
 const config = require("../config");
 const paths = require("../config/paths");
-const { registerRoutes, registerErrorHandlers } = require("./routes");
+const routes = require("./routes");
 
+// Set up the express app
 const app = express();
 
+// Log requests to the console.
+app.use(logger("dev"));
+
+// Will attempt to compress responses.
 app.use(compression());
-app.use(bodyParser.json());
-app.use(bodyParser.urlencoded({ extended: true }));
-app.use(express.static(paths.staticEntry));
 
+// Parse incoming requests data.
+app.use(express.json());
+app.use(express.urlencoded({ extended: true }));
+
+// Set up handlebars templating engine for layout files.
 app.engine("html", handlebars({ defaultLayout: "layout", extname: ".html" }));
 app.set("views", "app/templates");
 app.set("view engine", "html");
 
-registerRoutes(app);
-// registerErrorHandlers(app);
+// Set up the routes for the static assets.
+app.use(express.static(paths.staticEntry));
+
+routes.registerRoutes(app);
+routes.registerErrorHandlers(app);
 
 app.listen(config.port, () => {
   console.log(`🚀 Server started on port ${config.port}.`);

app/models/user.js

@@ -0,0 +1,21 @@
+const GitHub = require("../services/github");
+
+class User {
+  constructor(username, avatar_url, github_id) {
+    this.username = username;
+    this.avatar_url = avatar_url;
+    this.github_id = github_id;
+  }
+
+  static async find_or_create_from_token(access_token) {
+    try {
+      const data = await GitHub.get_user_from_token(access_token);
+    } catch (error) {
+      console.log("ERROR", error);
+    }
+
+    /* Find existing user or create new User instances */
+  }
+}
+
+module.exports = User;

app/routes.js

@@ -10,7 +10,7 @@ module.exports.registerRoutes = app => {
 module.exports.registerErrorHandlers = app => {
   app.use(function(err, req, res, next) {
     res.status(err.status || 500);
-    res.render("error", {
+    res.render("500", {
       message: err.message,
       error: config.env === "development" ? err : {}
     });

app/services/github.js

@@ -0,0 +1,41 @@
+const axios = require("axios");
+
+const api_url = "https://api.github.com";
+const authorize_url = "https://github.com/login/oauth/authorize";
+const token_url = "https://github.com/login/oauth/access_token";
+
+class GitHub {
+  constructor(client_id = "", client_secret = "", access_token = "") {
+    this.client_id = client_id;
+    this.client_secret = client_secret;
+    this.access_token = access_token;
+  }
+
+  authorization_url(scope = "") {
+    return `${authorize_url}?client_id=${this.client_id}&client_secret=${this.client_secret}&scope=${scope}`;
+  }
+
+  async get_token(code) {
+    /* Fetch GitHub Access Token for GitHub OAuth */
+    const config = { headers: { Accept: "application/json" } };
+    const params = {
+      code,
+      client_id: this.client_id,
+      client_secret: this.client_secret
+    };
+
+    const { data } = await axios.post(token_url, params, config);
+    return data.access_token;
+  }
+
+  static async get_user_from_token(access_token) {
+    /* Fetch user data using the access token. */
+    const url = api_url + "/user";
+    const config = { params: { access_token: access_token } };
+
+    const response = await axios.get(url, config);
+    return response.data;
+  }
+}
+
+module.exports = GitHub;

config/index.js

@@ -1,4 +1,10 @@
+const dotenv = require("dotenv");
+
+dotenv.config({ path: ".env" });
+
 module.exports = {
   port: process.env.PORT || 5000,
-  env: process.env.NODE_ENV || "development"
+  env: process.env.NODE_ENV || "development",
+  githubClientId: process.env.GITHUB_CLIENT_ID || "",
+  githubClientSecret: process.env.GITHUB_CLIENT_SECRET || ""
 };

package.json

@@ -3,15 +3,18 @@
   "version": "0.1.0",
   "description": "A hackathon starting point for new Nodejs applications",
   "scripts": {
-    "start": "node app/index.js",
-    "deploy": "NODE_ENV=production node app/index.js",
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "start": "nodemon app/index.js",
+    "deploy": "NODE_ENV=production node app/index.js"
   },
   "dependencies": {
-    "body-parser": "^1.18.3",
+    "axios": "^0.18.0",
     "compression": "^1.7.3",
     "dotenv": "^6.2.0",
     "express": "^4.16.4",
-    "express-handlebars": "^3.0.2"
+    "express-handlebars": "^3.0.2",
+    "morgan": "^1.9.1"
+  },
+  "devDependencies": {
+    "nodemon": "^1.18.10"
   }
 }