add health api endpoint to check health of API

Author: NickOvt

api.js

@@ -47,6 +47,7 @@ const dkimRoutes = require('./lib/api/dkim');
 const certsRoutes = require('./lib/api/certs');
 const webhooksRoutes = require('./lib/api/webhooks');
 const settingsRoutes = require('./lib/api/settings');
+const healthRoutes = require('./lib/api/health');
 const { SettingsHandler } = require('./lib/settings-handler');
 
 let userHandler;
@@ -561,6 +562,7 @@ module.exports = done => {
     certsRoutes(db, server);
     webhooksRoutes(db, server);
     settingsRoutes(db, server, settingsHandler);
+    healthRoutes(db, server);
 
     if (process.env.NODE_ENV === 'test') {
         server.get(

lib/api/health.js

@@ -0,0 +1,95 @@
+'use strict';
+
+const Joi = require('joi');
+const tools = require('../tools');
+const { successRes } = require('../schemas/response/general-schemas');
+
+module.exports = (db, server) => {
+    server.get(
+        {
+            path: '/health',
+            summary: 'Check the health of the API',
+            description: 'Check the status of the WildDuck API service, that is if db is connected and readable/writable, same for redis.',
+            tags: ['Health'],
+            validationObjs: {
+                requestBody: {},
+                queryParams: {},
+                pathParams: {},
+                response: {
+                    200: {
+                        description: 'Success',
+                        model: Joi.object({ success: successRes })
+                    },
+                    500: {
+                        description: 'Failed',
+                        model: Joi.object({ success: successRes, message: Joi.string().required().description('Error message specifying what went wrong') })
+                    }
+                }
+            }
+        },
+        tools.responseWrapper(async (req, res) => {
+            res.charSet('utf-8');
+
+            const currentTimestamp = Date.now() / 1000;
+
+            // 1) test that mongoDb is up
+            try {
+                const isConnected = await db.database.s.client.topology.isConnected();
+
+                if (!isConnected) {
+                    res.status(500);
+                    return res.json({
+                        success: false,
+                        message: 'DB is down'
+                    });
+                }
+            } catch (err) {
+                res.status(500);
+                return res.json({
+                    success: false,
+                    message: 'DB is down'
+                });
+            }
+
+            // 2) test that mongoDb is writeable
+
+            try {
+                await db.database.collection(`${currentTimestamp}`).insert({ a: 'testWrite' });
+                await db.database.collection(`${currentTimestamp}`).deleteOne({ a: 'testWrite' });
+            } catch (err) {
+                res.status(500);
+                return res.json({
+                    success: false,
+                    message: 'Could not write to DB'
+                });
+            }
+
+            // 3) test redis PING
+            db.redis.ping(err => {
+                if (err) {
+                    res.status(500);
+                    return res.json({
+                        success: false,
+                        message: 'Redis is down'
+                    });
+                }
+            });
+
+            // 4) test if redis is writeable
+            try {
+                await db.redis.set(`${currentTimestamp}`, 'testVal');
+                await db.redis.get(`${currentTimestamp}`);
+                await db.redis.del(`${currentTimestamp}`);
+            } catch (err) {
+                res.status(500);
+                return res.json({
+                    success: false,
+                    message: 'Redis is not writeable/readable'
+                });
+            }
+
+            res.status(200);
+            return res.json({ success: true });
+        })
+    );
+};