create announce.js to announce deploys to slack

bin/announce.js

@@ -0,0 +1,46 @@
+// this will announce that a deploy successfully finished into slack
+
+const https = require('https');
+
+let environment = process.env.SCRATCH_ENV || 'unknown environment';
+
+let branch = process.env.CIRCLE_BRANCH || 'unknown branch';
+
+let urlEng = process.env.SLACK_WEBHOOK_ENGINEERING;
+let urlMod = process.env.SLACK_WEBHOOK_MODS;
+let urlNotifications = process.env.SLACK_WEBHOOK_CIRCLECI_NOTIFICATIONS;
+
+let announcement = {text: `scratch-www has deployed branch ${branch} to ${environment}.`};
+
+const options = {
+    method: 'POST',
+    headers: {
+        'Content-Type': 'application/json'
+    }
+};
+
+const postMessage = (url, message, channelName) => {
+    let data = JSON.stringify(message);
+    const req = https.request(url, options, res => {
+        console.log(`statusCode: ${res.statusCode}`); // eslint-disable-line no-console
+        if (res.statusCode === 200) {
+            process.stdout.write(`announced to ${channelName}\n` + JSON.stringify(message) + '\n');
+        } else {
+            process.stdout.write(`FAILED to announce to slack`);
+        }
+    });
+
+    req.on('error', error => {
+        console.error(error); // eslint-disable-line no-console
+    });
+
+    req.write(data);
+    req.end();
+};
+
+postMessage(urlNotifications, announcement, '#circleci-notifications');
+
+if (environment === 'production'){
+    postMessage(urlEng, announcement, '#engineering');
+    postMessage(urlMod, announcement, '#scratch-mods');
+}