Initial draft of the Gitter -> Slack relay

.gitignore

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+/node_modules
+npm-debug.log
+.DS_Store
+/*.env

README.md

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+# Gitter Slack Relay
+
+Super simple Node application that listens to Gitter's realtime message streaming API and forwards those messages into a Slack room. Useful when you've got a public Gitter room, use Slack regularly and want to get notifications there.
+
+This currently does not go the other way, meaning no messages that you send to the Slack channel will go back to Gitter.
+
+Original inspiration came from https://github.com/reactor/gitter-slack-relay which is the exact same thing written in Java with Spring Boot and Reactor.
+
+## Usage
+
+```sh
+GITTER_ROOM_ID=<gitter room id> GITTER_TOKEN=<oauth bearer token> GITTER_ROOM_SLUG=<room URL slug> SLACK_HOOK_URL=<integration url> node gitter-to-slack.js
+```
+
+## Output
+
+When you send a message in Gitter:
+
+![gitter-message](https://user-images.githubusercontent.com/684275/28643934-1c78a700-721d-11e7-8321-a1f4b8e24f50.png)
+
+you'll get the JSON payload from Gitter in your console:
+
+```console
+Received Gitter payload: {"id":"messageid","text":"this shows up in Slack","html":"this shows up in Slack","sent":"2017-07-26T21:00:50.512Z","fromUser":{"id":"userid","username":"phillipuniverse","displayName":"Phillip Verheyden","url":"/phillipuniverse","avatarUrl":"https://avatars-02.gitter.im/gh/uv/4/phillipuniverse","avatarUrlSmall":"https://avatars2.githubusercontent.com/u/684275?v=4&s=60","avatarUrlMedium":"https://avatars2.githubusercontent.com/u/684275?v=4&s=128","v":6,"gv":"4"},"unread":true,"readBy":0,"urls":[],"mentions":[],"issues":[],"meta":[],"v":1}
+ forwarding to Slack
+```
+
+and see the message show up in Slack:
+
+![slack-message](https://user-images.githubusercontent.com/684275/28644032-7b6c3614-721d-11e7-8ac3-24cbec61a36e.png)
+
+### Environment Variables
+
+- **GITTER_ROOM_ID** - This is a non-human-readable form of the Gitter room id referred to from the Gitter API. The easiest way to get this ID is to go to [the Gitter rooms API docs](https://developer.gitter.im/docs/rooms-resource), copy the example request and pick out the room id that you want to listen to 
+- **GITTER_TOKEN** - The access token from https://developer.gitter.im/apps
+- **GITTER_ROOM_SLUG**  - Used to build the link from the Slack message to the message in Gitter. If you are in a Gitter room then this value is the part after https://gitter.im/. So if a room is accessible at https://gitter.im/BroadleafCommerce/BroadleafCommerce then this value would be `BroadleafCommerce/BroadleafCommerce`
+- **SLACK_HOOK_URL** - After creating a 'Custom Integration' in Slack (go to your team settings, Configure Apps -> Custom Integrations -> Add Configuration) this should be the 'Webhook URL' in the configuration settings

gitter-to-slack.js

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+var https = require('https');
+var request = require('request');
+var moment = require('moment');
+
+var roomId    = process.env.GITTER_ROOM_ID;
+var token     = process.env.GITTER_TOKEN;
+var gitterRoomSlug = process.env.GITTER_ROOM_SLUG;
+var slackHookUrl = process.env.SLACK_HOOK_URL;
+var heartbeat = " \n";
+
+var options = {
+  hostname: 'stream.gitter.im',
+  port:     443,
+  path:     '/v1/rooms/' + roomId + '/chatMessages',
+  method:   'GET',
+  headers:  {'Authorization': 'Bearer ' + token}
+};
+
+var req = https.request(options, function(res) {
+  res.on('data', function(chunk) {
+    var msg = chunk.toString();
+    if (msg !== heartbeat) {
+      console.log('Received Gitter payload: ' + msg + ' forwarding to Slack');
+      var gitterData = JSON.parse(msg);
+      var slackMessage = '<https://gitter.im/' + gitterRoomSlug + '?at=' + gitterData.id;
+      slackMessage += '|' + gitterData.fromUser.displayName;
+      var sentDate = moment(gitterData.sent).format('MMM-D h:mm A')
+      slackMessage += ' [' + sentDate + ']>';
+      slackMessage += ': ' + gitterData.text;
+      request.post(process.env.SLACK_HOOK_URL,
+        { json: { text: slackMessage} },
+        function (err, resp, body) {
+          if (err) {
+            console.log(err);
+          }
+        }
+      )
+    }
+  });
+});
+
+req.on('error', function(e) {
+  console.log('Something went wrong: ' + e.message);
+});
+
+req.end();

package.json

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+{
+  "name": "gitter-to-slack-node",
+  "version": "1.0.0",
+  "description": "",
+  "main": "gitter-to-slack.js",
+  "dependencies": {
+    "moment": "^2.18.1",
+    "request": "^2.81.0"
+  },
+  "devDependencies": {},
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC"
+}