koa-actuator - npm Package Compare versions

Comparing version 0.1.0 to 0.2.0

index.js

@@ -5,3 +5,4 @@ const compose = require('koa-compose');
 const appRootPath = require('app-root-path');
-const package_json = require(appRootPath + path.sep +'package.json');
+const package_json = require(appRootPath + path.sep + 'package.json');
+const assert = require('assert');
 
@@ -15,12 +16,38 @@ const HEALTH_PATH = '/health';
 /**
- * Writes {status: 'UP'} to response body if request path is /health
+ * Writes health checks results and aggregated status to response body if request path is /health
  */
-//TODO: add a callback function
-async function health(ctx, next) {
-  if (HEALTH_PATH == ctx.path)
-    ctx.body = {status: 'UP'};
-  else
-    await next();
+function health(checks, options) {
+  Object.keys(checks).forEach(name => assert(typeof(checks[name]) === 'function', `'${name}' check must be a function`));
+
+  const timeout = options.checkTimeout || 5000;
+
+  return async function healthMiddleware(ctx, next) {
+    if (HEALTH_PATH === ctx.path) {
+      const health = {status: 'UP'};
+      for (const checkName of Object.keys(checks)) {
+        const checkResult = await runCheck(checks[checkName], timeout);
+        health[checkName] = checkResult;
+        if (checkResult && checkResult.status === 'DOWN') {
+          health.status = checkResult.status;
+        }
+      }
+      ctx.status = health.status === 'UP' ? 200 : 503;
+      ctx.body = health;
+    } else {
+      await next();
+    }
+  }
 }
 
+async function runCheck(check, timeout) {
+  try {
+    return await Promise.race([
+      check(),
+      new Promise((resolve, reject) => setTimeout(() => reject(new Error('Check timed out')), timeout))
+    ]);
+  } catch (e) {
+    return {status: 'DOWN', error: e && (e.message || e.toString())};
+  }
+}
+
 /**
@@ -73,3 +100,3 @@ * Exposes application and resources information. E.g. name, version.
       heap: memory.heapTotal,
-      "heap.used": memory.heapUsed,
+      'heap.used': memory.heapUsed,
       resources: {
@@ -88,2 +115,4 @@ memory: memory,
 
-module.exports = compose([health, env, info, metrics]);
+module.exports = (healthChecks = {}, options = {}) => {
+  return compose([health(healthChecks, options), env, info, metrics]);
+};

package.json

 {
   "name": "koa-actuator",
-  "version": "0.1.0",
+  "version": "0.2.0",
   "description": "Healthcheck and monitoring middleware for koa inspired by java spring's actuators",
@@ -5,0 +5,0 @@ "main": "index.js",

README.md

@@ -16,5 +16,5 @@ # koa-actuator
 const app = new Koa();
-...
-app.use(actuator);
-...
+//...
+app.use(actuator());
+//...
 app.listen(3000);
@@ -29,5 +29,31 @@ ```
 ### /health
+Performs health checks and returns the results:
 ```
-{"status":"UP"}
+{
+  "status": "UP",
+  "db": {
+    "status": "UP",
+    "freeConnections": 10
+  },
+  "redis": {
+    "status": "UP",
+    "usedMemory": "52m",
+    "uptimeDays": 16
+  }
+}
 ```
+The statuses of the health checks are aggregated in a root-level `status` field. If at least one check yields `DOWN` status, the aggregated status will become `DOWN`. Health checks can be defined on actuator construction:
+ ```js
+const healthChecks = {
+  db: async () => {
+    return {
+      status: (await isDbAlive()) ? 'UP' : 'DOWN',
+      freeConnections: await freeDbConnectionsLeft()
+    }
+  },
+  //...
+};
+app.use(actuator(healthChecks));
+```
+A check can return an object of an arbitrary structure. If the returned structure contains `status` field, it will be counted in the aggregated status.
 
@@ -34,0 +60,0 @@ ### /env

test.js

 const actuator = require('.');
 const Koa = require('koa');
-const supertest = require('supertest');
+const request = require('supertest');
 const assert = require('chai').assert;
-const app = new Koa();
 
-describe('Koa actuator', () => {
+describe('koa-actuator', () => {
 
-  let request;
+  describe('/health', () => {
+    it('should return 200 and status UP if no checks defined', (done) => {
+      //arrange
+      const app = new Koa();
+      app.use(actuator());
 
-  before(() => {
-    app.use(actuator);
-    request = supertest.agent(app.listen());
-  });
+      //act & assert
+      request(app.callback())
+        .get('/health')
+        .expect(200)
+        .expect({status: 'UP'}, done);
+    });
 
-  describe('/health', () => {
-    it('GET should return 200 and status UP', (done) => {
-      request
+    it('should return 200 and status UP if sync and async checks pass', (done) => {
+      //arrange
+      const app = new Koa();
+      app.use(actuator({
+        db: () => Promise.resolve({status: 'UP', freeConnections: 10}),
+        redis: () => ({status: 'UP', usedMemory: '52m', uptimeDays: 16})
+      }));
+
+      //act & assert
+      request(app.callback())
         .get('/health')
         .expect(200)
-        .expect(/UP/, done);
+        .expect({
+          status: 'UP',
+          db: {status: 'UP', freeConnections: 10},
+          redis: {status: 'UP', usedMemory: '52m', uptimeDays: 16}
+        }, done);
     });
+
+    it('should return 503 and status DOWN if any check fails', (done) => {
+      //arrange
+      const app = new Koa();
+      app.use(actuator({
+        db: () => Promise.resolve({status: 'UP', freeConnections: 10}),
+        redis: () => Promise.resolve({status: 'DOWN', usedMemory: '52m', uptimeDays: 16})
+      }));
+
+      //act & assert
+      request(app.callback())
+        .get('/health')
+        .expect(503)
+        .expect({
+          status: 'DOWN',
+          db: {status: 'UP', freeConnections: 10},
+          redis: {status: 'DOWN', usedMemory: '52m', uptimeDays: 16}
+        }, done);
+    });
+
+    it('should return 503 and status DOWN if a sync check throws exception', (done) => {
+      //arrange
+      const app = new Koa();
+      app.use(actuator({
+        db: () => { throw new Error('unexpected error'); },
+        redis: () => Promise.resolve({status: 'UP', usedMemory: '52m', uptimeDays: 16})
+      }));
+
+      //act & assert
+      request(app.callback())
+        .get('/health')
+        .expect(503)
+        .expect({
+          status: 'DOWN',
+          db: {status: 'DOWN', error: 'unexpected error'},
+          redis: {status: 'UP', usedMemory: '52m', uptimeDays: 16}
+        }, done);
+    });
+
+    it('should return 503 and status DOWN if an async check rejects promise', (done) => {
+      //arrange
+      const app = new Koa();
+      app.use(actuator({
+        db: () => Promise.resolve({status: 'UP', freeConnections: 10}),
+        redis: () => Promise.reject('unexpected async error')
+      }));
+
+      //act & assert
+      request(app.callback())
+        .get('/health')
+        .expect(503)
+        .expect({
+          status: 'DOWN',
+          db: {status: 'UP', freeConnections: 10},
+          redis: {status: 'DOWN', error: 'unexpected async error'}
+        }, done);
+    });
+
+    it('should return 503 and status DOWN if an async check times out', (done) => {
+      //arrange
+      const app = new Koa();
+      const options = {checkTimeout: 100};
+      app.use(actuator({
+        db: () => new Promise((resolve, reject) => setTimeout(() => resolve({status: 'UP', freeConnections: 10}), 3000))
+      }, options));
+
+      //act & assert
+      request(app.callback())
+        .get('/health')
+        .expect(503)
+        .expect({
+          status: 'DOWN',
+          db: {status: 'DOWN', error: 'Check timed out'},
+        }, done);
+    });
   });
 
   describe('/info', () => {
-    it('GET should return 200 and version', (done) => {
-      request
+    it('should return 200 and version', (done) => {
+      //arrange
+      const app = new Koa();
+      app.use(actuator());
+
+      //act & assert
+      request(app.callback())
         .get('/info')
@@ -39,8 +135,10 @@ .expect(200)
   describe('/env', () => {
-    it('GET should return 200 and the list of environment variables', (done) => {
+    it('should return 200 and the list of environment variables', (done) => {
       //arrange
       process.env.TEST_VAR = 'test';
+      const app = new Koa();
+      app.use(actuator());
 
       //act & assert
-      request
+      request(app.callback())
         .get('/env')
@@ -60,5 +158,7 @@ .expect(200)
       process.env.PASSWORD = 'test-password';
+      const app = new Koa();
+      app.use(actuator());
 
       //act & assert
-      request
+      request(app.callback())
         .get('/env')
@@ -78,4 +178,8 @@ .expect(200)
     it('should return 200 and show some service info (like uptime, heap usage etc)', (done) => {
+      //arrange
+      const app = new Koa();
+      app.use(actuator());
+
       //act & assert
-      request
+      request(app.callback())
         .get('/metrics')
@@ -94,2 +198,2 @@ .expect(200)
   });
-});
+});

New alerts

Dynamic require

Supply chain risk

Dynamic require can indicate the package is performing dangerous or unsafe dynamic code execution.

Found 1 instance in 1 package

Fixed alerts

Dynamic require

Supply chain risk

Dynamic require can indicate the package is performing dangerous or unsafe dynamic code execution.

Found 1 instance in 1 package

Improved metrics

Total package byte prevSize

14628

increased by54.25%

Lines of code

278

increased by77.07%

Number of lines in readme file

114

increased by29.55%

No dependency changes