Service Libraries

A collection of utilities for services in mircoservice-poc

Installation

The easiest way to install service-libraries is using NPM. If you have Node.js installed, it is most likely that you have NPM installed as well.

$ npm install @hai.dinh/service-libraries

Usage

httpHandler

Being inspired by AWS Lambda response for API Gateway styling, this function retrieves your response, which being like AWS Lambda response, then transform to express response

function simpleResponse(req) {
  return {
      statusCode: 200,
      body: {
          message: 'Hello World !'
      },
      headers: {
          'Content-Type': 'application/json'
      }
  }
}

...
import express from 'express';
import { httpHandler } from '@hai.dinh/service-libraries';

const app = express();

app.get('/hello-world', httpHandler(simpleResponse))

schemaValidator

schemaValidator is basically instance of ajv (to validate data with the corresponding schema), including pre-defined basic configuration.

To use schemaValidator, follow the instruction

import { schemaValidator } from '@hai.dinh/service-libraries';

const validator = schemaValidator.compile(schema);
const isValid = validator(yourData);

if (!isValid) {
    console.log('Your data is invalid.', validator.errors)
}

ServiceClientFactory

Taking file service-env.json (render by service-registry-cli pull) as input, ServiceClientFactory acts as service discovery in microservice system to find the endpoint of targeted service. To use this, do the following:

import { ServiceClientFactory } from '@hai.dinh/service-libraries';

...

const serviceClient = await ServiceClientFactory.create(<service-id>);

const response = await serviceClient.request(config)

ServiceClientFactory API

• serviceClient.request(config: AxiosConfig)

    // Send a POST request
    const res = await serviceClient.request({
        method: 'post',
        url: '/user/12345',
        data: {
            firstName: 'Fred',
            lastName: 'Flintstone'
        }
    });

ServiceClientFactory uses axios behind the scene. For full configuration, you can get in here.

StorageClient

import { StorageClient } from '@hai.dinh/service-libraries';

API

• create

    const storageClient = await StorageClient.create();

    const record = await storageClient.create(documentPath, {
        "Content": documentContent,
        "Type": documentType,
        "Attributes": documentAttributs,
    })

• get

    const storageClient = await StorageClient.create();

    const record = await storageClient.get(documentPath)

• list

    const storageClient = await StorageClient.create();

    const record = await storageClient.list(options)

• update

    const storageClient = await StorageClient.create();

    const record = await storageClient.update(documentPath, {
        "Content": documentContent,
        "Type": documentType,
        "Attributes": documentAttributs,
    })

• delete

    const storageClient = await StorageClient.create();

    const record = await storageClient.delete(documentPath)

Middlewares

traceRequest

traceRequest middleware allow Express application to capture and foward X-Request-ID from original request headers, then set it to process environment variable for other libraries(logger, http client ...) can consume it

• Usage

import { traceRequest } from '@hai.dinh/service-libraries/middlewares';

...
// in your service (Express)
const app = express();

app.use(traceRequest)

console.log(process.env['X-Request-Id'])

useInstrumentation

useInstrumentation provides instrumentation to support logging for application. Log will be streamed to stdout and saved to file log/app.log

import { useInstrumentation } from '@hai.dinh/service-libraries/middlewares';

...
// in your service (Express)
const app = express();

app.use(useInstrumentation)

// get instrumentation from your request
app.get('/', (req, res) => {
    const { instrumentation } = res;
})

Instrumentation API

• trace

instrumentation.trace('Process started!');
// Output
// If X-Request-ID is NA
// [2010-01-17 11:43:37.987] [TRACE] - - Process started!
// IF X-Request-ID is available (by useTraceRequest)
// [2010-01-17 11:43:37.987] [TRACE] 1212121 - Process started!

• debug

instrumentation.debug('Got notification');
// Output
// If X-Request-ID is NA
// [2010-01-17 11:43:37.987] [DEBUG] - - Got notification!
// IF X-Request-ID is available (by useTraceRequest)
// [2010-01-17 11:43:37.987] [DEBUG] 1212121 - Got notification!

• info

instrumentation.info('Hello World!');
// Output
// If X-Request-ID is NA
// [2010-01-17 11:43:37.987] [INFO] - - Hello World!
// IF X-Request-ID is available (by useTraceRequest)
// [2010-01-17 11:43:37.987] [INFO] 1212121 - Hello World!

• warn

instrumentation.warn('Warn!');
// Output
// If X-Request-ID is NA
// [2010-01-17 11:43:37.987] [WARN] - - Warn!
// IF X-Request-ID is available (by useTraceRequest)
// [2010-01-17 11:43:37.987] [WARN] 121313 - Warn!

• error

instrumentation.error('Error!');

// Output
// If X-Request-ID is NA
// [2010-01-17 11:43:37.987] [ERROR] - - Error!
// IF X-Request-ID is available (by useTraceRequest)
// [2010-01-17 11:43:37.987] [ERROR] 123212 - Error!

useHttpLogger

useHttpLogger allow your Express server to log http as CSL format.

Below is the example of log

127.0.0.1 - [email protected] [10/Oct/2000:13:55:36 -0700] "GET /apache_pb.gif HTTP/1.0" 200 2326 "http://referer.com" "PostmanRuntime/7.23.0" vxve23sdgs45sdvw


log-format = %(addr) %(ident) %(user) [%(ltime)] "%(method) %(uri) %(proto)" %(status) 
%(size) "%(referer)" "%(uagent)" %(requestid)

• Usage:

import { useHttpLogger } from '@hai.dinh/service-libraries/middlewares';

...
// in your service (Express)
const app = express();

app.use(useHttpLogger)