Merge pull request #3822 from alphagov/pp-11683-healthcontroller-upda…

…te-to-use-axios

PP-11683 Update healthcheck controller to use Axios

app/controllers/healthcheck.controller.js

@@ -2,7 +2,10 @@
 const _ = require('lodash')
 const logger = require('../utils/logger')(__filename)
 const { getLoggingFields } = require('../utils/logging-fields-helper')
-const baseClient = require('../services/clients/base.client/base.client')
+const { Client } = require('@govuk-pay/pay-js-commons/lib/utils/axios-base-client/axios-base-client')
+const { configureClient } = require('../services/clients/base/config')
+const SERVICE_NAME = 'frontend'
+const client = new Client(SERVICE_NAME)
 
 const healthyPingResponse = { ping: { healthy: true } }
 
@@ -11,21 +14,34 @@ const respond = (res, statusCode, data) => {
   res.end(JSON.stringify(data))
 }
 
-module.exports.healthcheck = (req, res) => {
+module.exports.healthcheck = async (req, res) => {
   if (process.env.FORWARD_PROXY_URL) {
-    baseClient.get(`${process.env.FORWARD_PROXY_URL}/nginx_status`, {}, (err, response) => {
-      const statusCode = _.get(response, 'statusCode')
-      if (err || statusCode !== 200) {
+    const url = `${process.env.FORWARD_PROXY_URL}/nginx_status`
+
+    configureClient(client, url)
+
+    let response
+
+    try {
+      response = await client.get(url, 'Healthcheck')
+
+      if (response.status !== 200) {
         logger.error('Healthchecking forward proxy returned error', {
           ...getLoggingFields(req),
-          error: err,
-          status_code: statusCode
+          status_code: response.status
         })
         respond(res, 502, _.merge(healthyPingResponse, { proxy: { healthy: false } }))
       } else {
-        respond(res, 200, _.merge(healthyPingResponse, { proxy: { healthy: true } }))
+        respond(res, 200, healthyPingResponse)
       }
-    })
+    } catch (err) {
+      logger.error('Healthchecking forward proxy returned error', {
+        ...getLoggingFields(req),
+        error: err,
+        status_code: response.status
+      })
+      respond(res, 502, _.merge(healthyPingResponse, { proxy: { healthy: false } }))
+    }
   } else {
     respond(res, 200, healthyPingResponse)
   }

app/services/clients/base/config.js

@@ -0,0 +1,40 @@
+'use strict'
+
+const requestLogger = require('./request-logger')
+const { getRequestCorrelationIDField } = require('./request-context')
+const { CORRELATION_HEADER } = require('../../../../config/correlation-header')
+
+function transformRequestAddHeaders () {
+  const correlationId = getRequestCorrelationIDField()
+  const headers = {}
+  if (correlationId) {
+    headers[CORRELATION_HEADER] = correlationId
+  }
+  return headers
+}
+
+function onRequestStart (context) {
+  requestLogger.logRequestStart(context)
+}
+
+function onSuccessResponse (context) {
+  requestLogger.logRequestEnd(context)
+}
+
+function onFailureResponse (context) {
+  requestLogger.logRequestEnd(context)
+  requestLogger.logRequestFailure(context)
+}
+
+function configureClient (client, baseUrl) {
+  client.configure(baseUrl, {
+    transformRequestAddHeaders,
+    onRequestStart,
+    onSuccessResponse,
+    onFailureResponse
+  })
+}
+
+module.exports = {
+  configureClient
+}

app/services/clients/base/config.test.js

@@ -0,0 +1,90 @@
+'use strict'
+
+const nock = require('nock')
+const sinon = require('sinon')
+const proxyquire = require('proxyquire')
+const { expect } = require('chai')
+const { Client } = require('@govuk-pay/pay-js-commons/lib/utils/axios-base-client/axios-base-client')
+
+const baseUrl = 'http://localhost:8000'
+const app = 'an-app'
+
+const logInfoSpy = sinon.spy()
+
+function getConfigWithMocks (correlationId) {
+  const config = proxyquire('./config.js', {
+    './request-context': {
+      getRequestCorrelationIDField: () => correlationId
+    },
+    './request-logger': proxyquire('./request-logger', {
+      '../../../utils/logger': () => ({
+        info: logInfoSpy
+      })
+    })
+  })
+  return config
+}
+
+describe('Client config', () => {
+  beforeEach(() => {
+    logInfoSpy.resetHistory()
+  })
+
+  describe('Headers', () => {
+    it('should add correlation ID as header when correlation ID exists on request context', async () => {
+      const client = new Client(app)
+      const config = getConfigWithMocks('abc123')
+
+      config.configureClient(client, baseUrl)
+
+      nock(baseUrl)
+        .get('/')
+        .reply(200)
+
+      const response = await client.get('/', 'foo')
+
+      expect(response.status).to.equal(200)
+      expect(response.request.headers).to.have.property('x-request-id', 'abc123')
+    })
+
+    it('should not add correlation ID as header when correlation ID does not exist on request context', async () => {
+      const client = new Client(app)
+      const config = getConfigWithMocks()
+      config.configureClient(client, baseUrl)
+
+      nock(baseUrl)
+        .get('/')
+        .reply(200)
+
+      const response = await client.get('/', 'foo')
+      expect(response.status).to.equal(200)
+      expect(response.request.headers).to.not.have.key('x-request-id')
+    })
+  })
+
+  describe('Logging', () => {
+    it('should log request start', async () => {
+      const client = new Client(app)
+      const config = getConfigWithMocks('abc123')
+      config.configureClient(client, baseUrl)
+
+      nock(baseUrl)
+        .get('/')
+        .reply(200)
+
+      const response = await client.get('/', 'do something', {
+        additionalLoggingFields: { foo: 'bar' }
+      })
+
+      expect(response.status).to.equal(200)
+
+      sinon.assert.calledWith(logInfoSpy, 'Calling an-app to do something', {
+        service: app,
+        method: 'get',
+        url: '/',
+        description: 'do something',
+        foo: 'bar'
+      })
+    })
+  })
+})

app/services/clients/base/request-context.js

@@ -0,0 +1,38 @@
+'use strict'
+
+const { CORRELATION_ID } = require('@govuk-pay/pay-js-commons').logging.keys
+
+const { AsyncLocalStorage } = require('async_hooks')
+const { CORRELATION_HEADER } = require('../../../../config/correlation-header')
+
+const asyncLocalStorage = new AsyncLocalStorage()
+
+function requestContextMiddleware (req, res, next) {
+  asyncLocalStorage.run({}, () => {
+    asyncLocalStorage.getStore()[CORRELATION_ID] = req.headers[CORRELATION_HEADER]
+    next()
+  })
+}
+
+function addField (key, value) {
+  if (asyncLocalStorage.getStore()) {
+    asyncLocalStorage.getStore()[key] = value
+  }
+}
+
+function getRequestCorrelationIDField () {
+  if (asyncLocalStorage.getStore()) {
+    return asyncLocalStorage.getStore()[CORRELATION_ID]
+  }
+}
+
+function getLoggingFields () {
+  return asyncLocalStorage.getStore()
+}
+
+module.exports = {
+  requestContextMiddleware,
+  addField,
+  getRequestCorrelationIDField,
+  getLoggingFields
+}

app/services/clients/base/request-logger.js

@@ -0,0 +1,53 @@
+const logger = require('../../../utils/logger')(__filename)
+
+module.exports = {
+  logRequestStart: context => {
+    logger.info(`Calling ${context.service} to ${context.description}`, {
+      service: context.service,
+      method: context.method,
+      url: context.url,
+      description: context.description,
+      ...context.additionalLoggingFields
+    })
+  },
+
+  logRequestEnd: (context) => {
+    const responseTime = (context.startTime && new Date() - context.startTime) || context.responseTime
+    logger.info(`${context.method} to ${context.url} ended - elapsed time: ${responseTime} ms`, {
+      service: context.service,
+      method: context.method,
+      url: context.url,
+      description: context.description,
+      response_time: responseTime,
+      status: context.status,
+      ...context.additionalLoggingFields
+    })
+  },
+
+  logRequestFailure: (context) => {
+    let message = `Calling ${context.service} to ${context.description} failed`
+    if (context.retry) {
+      message = message + ' - request will be retried'
+    }
+
+    logger.info(message, {
+      service: context.service,
+      method: context.method,
+      url: context.url,
+      description: context.description,
+      status: context.status,
+      ...context.additionalLoggingFields
+    })
+  },
+
+  logRequestError: (context, error) => {
+    logger.error(`Calling ${context.service} to ${context.description} threw exception`, {
+      service: context.service,
+      method: context.method,
+      url: context.url,
+      description: context.description,
+      error: error,
+      ...context.additionalLoggingFields
+    })
+  }
+}