Merge pull request #522 from calzoneman/sioconfig-migration

Migrate socket.io configuration to new API

NEWS.md

@@ -1,3 +1,11 @@
+2015-10-25
+==========
+
+In order to support future clustering support, the legacy `/sioconfig`
+endpoint is being deprecated.  Instead, you should make a request to
+`/socketconfig/<channel name>.json`.  See [the
+documentation](docs/socketconfig.md) for more information.
+
 2015-10-04
 ==========
 

docs/socketconfig.md

@@ -0,0 +1,57 @@
+Socket.IO Client Configuration
+==============================
+
+As of 2015-10-25, the legacy `/sioconfig` JavaScript for retrieving connection
+information is being deprecated in favor of a new API.  The purpose of this
+change is to allow partitioning channels across multiple servers in order to
+better handle increasing traffic.
+
+To get the socket.io configuration for the server hosting a particular channel,
+make a `GET` request to `/socketconfig/<channel name>.json`.  The response will
+be a JSON object containing a list of acceptable servers to connect to, or an
+error message.
+
+Examples:
+
+```
+GET /socketconfig/test.json
+200 OK
+
+{
+    "servers": [
+        {
+            "url": "https://localhost:8443",
+            "secure": true
+        },
+        {
+            "url": "http://localhost:1337",
+            "secure": false
+        },
+        {
+            "url": "https://local6:8443",
+            "secure": true,
+            "ipv6": true
+        },
+        {
+            "url": "http://local6:1337",
+            "secure": false,
+            "ipv6": true
+        }
+    ]
+}
+
+GET /socketconfig/$invalid$.json
+404 Not Found
+
+{
+    "error": "Channel \"$invalid$\" does not exist."
+}
+```
+
+Each entry in the `servers` array has `"secure":true` if the connection is
+secured with TLS, otherwise it it is false.  An entry with `"ipv6":true`
+indicates that the server is listening on the IPv6 protocol.
+
+You can pick any URL to connect socket.io to in order to join the specified
+channel.  I recommend picking one with `"secure":true`, only choosing an
+insecure connection if implementing a TLS connection is infeasible.

package.json

@@ -2,7 +2,7 @@
   "author": "Calvin Montgomery",
   "name": "CyTube",
   "description": "Online media synchronizer and chat",
-  "version": "3.11.2",
+  "version": "3.12.0",
   "repository": {
     "url": "http://github.com/calzoneman/sync"
   },

src/configuration/ioconfig.js

@@ -0,0 +1,47 @@
+export default class IOConfiguration {
+    constructor(config) {
+        this.config = config;
+    }
+
+    getSocketEndpoints() {
+        return this.config.endpoints.slice();
+    }
+}
+
+IOConfiguration.fromOldConfig = function (oldConfig) {
+    const config = {
+        endpoints: []
+    };
+
+    if (oldConfig.get('io.ipv4-ssl')) {
+        config.endpoints.push({
+            url: oldConfig.get('io.ipv4-ssl'),
+            secure: true
+        });
+    }
+
+    if (oldConfig.get('io.ipv4-nossl')) {
+        config.endpoints.push({
+            url: oldConfig.get('io.ipv4-nossl'),
+            secure: false
+        });
+    }
+
+    if (oldConfig.get('io.ipv6-ssl')) {
+        config.endpoints.push({
+            url: oldConfig.get('io.ipv4-ssl'),
+            secure: true,
+            ipv6: true
+        });
+    }
+
+    if (oldConfig.get('io.ipv6-nossl')) {
+        config.endpoints.push({
+            url: oldConfig.get('io.ipv4-nossl'),
+            secure: false,
+            ipv6: true
+        });
+    }
+
+    return new IOConfiguration(config);
+};

src/io/cluster/nullclusterclient.js

@@ -0,0 +1,14 @@
+import Promise from 'bluebird';
+
+export default class NullClusterClient {
+    constructor(ioConfig) {
+        this.ioConfig = ioConfig;
+    }
+
+    getSocketConfig(channel) {
+        const servers = this.ioConfig.getSocketEndpoints();
+        return Promise.resolve({
+            servers: servers
+        });
+    }
+}

src/web/routes/socketconfig.js

@@ -0,0 +1,27 @@
+import IOConfiguration from '../../configuration/ioconfig';
+import NullClusterClient from '../../io/cluster/nullclusterclient';
+import Config from '../../config';
+import CyTubeUtil from '../../utilities';
+import Logger from '../../logger';
+
+export default function initialize(app) {
+    const ioConfig = IOConfiguration.fromOldConfig(Config);
+    const clusterClient = new NullClusterClient(ioConfig);
+
+    app.get('/socketconfig/:channel.json', (req, res) => {
+        if (!req.params.channel || !CyTubeUtil.isValidChannelName(req.params.channel)) {
+            return res.status(404).json({
+                error: `Channel "${req.params.channel}" does not exist.`
+            });
+        }
+
+        clusterClient.getSocketConfig(req.params.channel).then(config => {
+            res.json(config);
+        }).catch(err => {
+            Logger.errlog.log(err.stack);
+            return res.status(500).json({
+                error: err.message
+            });
+        });
+    });
+}

src/web/webserver.js

@@ -117,7 +117,8 @@ function handleIndex(req, res) {
 }
 
 /**
- * Handles a request for the socket.io information
+ * Legacy socket.io configuration endpoint.  This is being migrated to
+ * /socketconfig/<channel name>.json (see ./routes/socketconfig.js)
  */
 function handleSocketConfig(req, res) {
     if (/\.json$/.test(req.path)) {
@@ -243,6 +244,7 @@ module.exports = {
         app.get("/r/:channel", handleChannel);
         app.get("/", handleIndex);
         app.get("/sioconfig(.json)?", handleSocketConfig);
+        require("./routes/socketconfig")(app);
         app.get("/useragreement", handleUserAgreement);
         app.get("/contact", handleContactPage);
         require("./auth").init(app);

templates/channel.jade

@@ -239,7 +239,6 @@ html(lang="en")
     mixin footer()
     script(src=sioSource)
     script(src="/js/data.js")
-    script(src="/sioconfig")
     script(src="/js/util.js")
     script(src="/js/player.js")
     script(src="/js/paginator.js")

www/js/callbacks.js

@@ -1096,27 +1096,57 @@ setupCallbacks = function() {
             });
         })(key);
     }
-}
+};
 
-try {
+(function () {
     if (typeof io === "undefined") {
         makeAlert("Uh oh!", "It appears the connection to <code>" + IO_URL + "</code> " +
                             "has failed.  If this error persists, a firewall or " +
                             "antivirus is likely blocking the connection, or the " +
                             "server is down.", "alert-danger")
             .appendTo($("#announcements"));
-        throw false;
+        Callbacks.disconnect();
+        return;
     }
 
-    var opts = { transports: ["websocket", "polling"] };
-    if (IO_URL === IO_URLS["ipv4-ssl"] || IO_URL === IO_URLS["ipv6-ssl"]) {
-        opts.secure = true;
-        socket = io(IO_URL, { secure: true });
+    $.getJSON("/socketconfig/" + CHANNEL.name + ".json")
+        .done(function (socketConfig) {
+            if (socketConfig.error) {
+                makeAlert("Error", "Socket.io configuration returned error: " +
+                        socketConfig.error, "alert-danger")
+                    .appendTo($("#announcements"));
+                return;
             }
-    socket = io(IO_URL, opts);
+
+            var chosenServer = null;
+            socketConfig.servers.forEach(function (server) {
+                if (chosenServer === null) {
+                    chosenServer = server;
+                } else if (server.secure && !chosenServer.secure) {
+                    chosenServer = server;
+                } else if (!server.ipv6Only && chosenServer.ipv6Only) {
+                    chosenServer = server;
+                }
+            });
+
+            if (chosenServer === null) {
+                makeAlert("Error",
+                        "Socket.io configuration was unable to find a suitable server",
+                        "alert-danger")
+                    .appendTo($("#announcements"));
+            }
+
+            var opts = {
+                transports: ["websocket", "polling"],
+                secure: chosenServer.secure
+            };
+
+            socket = io(chosenServer.url, opts);
             setupCallbacks();
-} catch (e) {
-    if (e) {
+        }).fail(function () {
+            makeAlert("Error", "Failed to retrieve socket.io configuration",
+                    "alert-danger")
+                .appendTo($("#announcements"));
             Callbacks.disconnect();
-    }
-}
+        });
+})();