Use terminus for liveness/readiness probes & sigterms (#28)

* Use terminus for liveness/readiness & SIGTERMS

* WIP

Author: adinhodovic

app.js

@@ -13,6 +13,8 @@ import logMaker from './log';
 
 const log = logMaker('app.js', { level: process.env.DEBUG_LEVEL || 'info' });
 
+const { createTerminus } = require('@godaddy/terminus');
+
 function maybeReplaceWithContentsOfFile(obj, field) {
   const potentialFile = obj[field];
   if (potentialFile != null && fs.existsSync(potentialFile)) {
@@ -54,9 +56,6 @@ app.use(bodyParser.urlencoded({
   extended: false,
 }));
 
-// The Health Check
-app.use('/export/status', require('express-healthcheck')());
-
 app.get('/export/:userid', async (req, res) => {
   // Set the timeout for the request. Make it 10 seconds longer than
   // our configured timeout to give the service time to cancel the API data
@@ -155,8 +154,29 @@ app.get('/export/:userid', async (req, res) => {
   }
 });
 
+function beforeShutdown() {
+  return new Promise((resolve) => {
+    // Ensure that the export request can time out
+    // without being forcefully killed
+    setTimeout(resolve, config.exportTimeout + 10000);
+  });
+}
+
+function healthCheck() {
+  return Promise.resolve();
+}
+
+const options = {
+  healthChecks: {
+    '/export/status': healthCheck,
+  },
+  beforeShutdown,
+};
+
 if (config.httpPort) {
-  app.server = http.createServer(app).listen(config.httpPort, () => {
+  const server = http.createServer(app);
+  createTerminus(server, options);
+  server.listen(config.httpPort, () => {
     log.info(`Listening for HTTP on ${config.httpPort}`);
   });
 }
@@ -166,7 +186,9 @@ if (config.httpsPort) {
     log.error('SSL endpoint is enabled, but no valid config was found. Exiting.');
     process.exit(1);
   } else {
-    https.createServer(config.httpsConfig, app).listen(config.httpsPort, () => {
+    const server = https.createServer(config.httpsConfig, app);
+    createTerminus(server, options);
+    server.listen(config.httpsPort, () => {
       log.info(`Listening for HTTPS on ${config.httpsPort}`);
     });
   }

package.json

@@ -16,13 +16,13 @@
   "author": "Lennart Goedhart <lennart@tidepool.org>",
   "private": false,
   "dependencies": {
+    "@godaddy/terminus": "^4.4.1",
     "@tidepool/data-tools": "2.4.0",
     "axios": "0.19.2",
     "body-parser": "1.19.0",
     "bunyan": "1.8.12",
     "esm": "3.2.25",
     "express": "4.17.1",
-    "express-healthcheck": "0.1.0",
     "lodash": "4.17.15",
     "query-string": "6.13.1"
   },

yarn.lock

@@ -125,6 +125,14 @@
     lodash "^4.17.13"
     to-fast-properties "^2.0.0"
 
+"@godaddy/terminus@^4.4.1":
+  version "4.4.1"
+  resolved "https://registry.yarnpkg.com/@godaddy/terminus/-/terminus-4.4.1.tgz#0a54ba1363452a8199f46aed3f7931d55287c6b0"
+  integrity sha512-ZPwsG7xN+B2bvnEu6+o0rBPAFbXmm6Bk/RAR4b/nhjNOSJtbVFYTd+JSaJYL/jyESqcTcAyzlWO0dmbT4YsckQ==
+  dependencies:
+    es6-promisify "^6.0.2"
+    stoppable "^1.1.0"
+
 "@tidepool/data-tools@2.4.0":
   version "2.4.0"
   resolved "https://registry.npmjs.org/@tidepool/data-tools/-/data-tools-2.4.0.tgz#029242563445e72dd844e71f63b4fe41ec846de2"
@@ -788,6 +796,11 @@ es-to-primitive@^1.2.1:
     is-date-object "^1.0.1"
     is-symbol "^1.0.2"
 
+es6-promisify@^6.0.2:
+  version "6.1.1"
+  resolved "https://registry.yarnpkg.com/es6-promisify/-/es6-promisify-6.1.1.tgz#46837651b7b06bf6fff893d03f29393668d01621"
+  integrity sha512-HBL8I3mIki5C1Cc9QjKUenHtnG0A5/xA8Q/AllRcfiwl2CZFXGK7ddBiCoRwAix4i2KxcQfjtIVcrVbB3vbmwg==
+
 escape-html@~1.0.3:
   version "1.0.3"
   resolved "https://registry.npmjs.org/escape-html/-/escape-html-1.0.3.tgz#0258eae4d3d0c0974de1c169188ef0051d1d1988"
@@ -1059,11 +1072,6 @@ exceljs@3.8.0:
     unzipper "^0.9.12"
     uuid "^3.3.3"
 
-express-healthcheck@0.1.0:
-  version "0.1.0"
-  resolved "https://registry.npmjs.org/express-healthcheck/-/express-healthcheck-0.1.0.tgz#cabec78129c4cb90cd7fb894dfae21b82e27cb07"
-  integrity sha1-yr7HgSnEy5DNf7iU364huC4nywc=
-
 express@4.17.1:
   version "4.17.1"
   resolved "https://registry.npmjs.org/express/-/express-4.17.1.tgz#4491fc38605cf51f8629d39c2b5d026f98a4c134"
@@ -2461,6 +2469,11 @@ sprintf-js@~1.0.2:
   resolved "https://registry.npmjs.org/statuses/-/statuses-1.5.0.tgz#161c7dac177659fd9811f43771fa99381478628c"
   integrity sha1-Fhx9rBd2Wf2YEfQ3cfqZOBR4Yow=
 
+stoppable@^1.1.0:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/stoppable/-/stoppable-1.1.0.tgz#32da568e83ea488b08e4d7ea2c3bcc9d75015d5b"
+  integrity sha512-KXDYZ9dszj6bzvnEMRYvxgeTHU74QBFL54XKtP3nyMuJ81CFYtABZ3bAzL2EdFUaEwJOBOgENyFj3R7oTzDyyw==
+
 stream-combiner@~0.0.4:
   version "0.0.4"
   resolved "https://registry.npmjs.org/stream-combiner/-/stream-combiner-0.0.4.tgz#4d5e433c185261dde623ca3f44c586bcf5c4ad14"