node-web-engine app

TODO: add build badges here

Node web engine is an unopinionated Dependency Injection framework which serves as a core base to all microservices cross-cutting services (e.g. logger, config, mongodb, redis, kafka etc.) as well as a DI. The web-engine requires upload to an NPM repository (or mirror), so that it'll be used as a base module to each microservice

Requirements

• Node 8+
• esm - The framework is coded ES6 module style, be sure to use node -r esm <your-service> when running. esm can be installed globally

npm i esm -g

Basic Usage

First, install the module:

npm i web-engine

initialize the service:

import {initServer} from 'web-engine'

var {app, container, router} = initServer()

app.listen(3000, () => {
    console.log('server started')
}) 

//...

Now add your stuff here...

Adding your own services and routes:

Your services and routes are automatically scanned under /src/routes and /src/services/ when initServer is being called. see users.js and usersServices.js examples

Other injected services and repositories

Classes exported under /src/services and /src/repositories are also automatically scanned, initialized (lazily) and added to the DI container. Some core services were added to the module, and can be used in the apps:

• LoggerFactory

   var logger = container.cradle.loggerFactory.logger
      logger.debug('12345')
  

The Logger default configuration is set in the default and production configuration files. Essentially in production mode, the minimal log level is set to error. This configuration (as with any configuration) can be overriden in the app.

{
   "logger": {
       "isLogstashEnabled":false,
       "file": {
            "level": "debug",
            "relativePath": "./logs/app.log"
        },
       "console": {
            "level": "debug",
            "handleExceptions": true,
            "json": false,
            "colorize": true
        },
        "logstash": {
            "level": "debug",
            "port": 5000,
            "node_name": "web",
            "host": "logstash"
        }
   }       
}

Logstash can also be overriden with environment variables: $CLIENT_LOGSTASH_HOST, $CLIENT_LOGSTASH_PORT, $LOGSTASH_NODE_NAME

Healthcheck Service

Each microservice has to implement healthcheck service and healthcheck test

export default class HealthcheckService {
    
    async check(){

    }
}

The parent service calls the child service during each healtcheck interval(localhost:3000/healthcheck), then returns true/false (via routing file) based on the child's healthcheck logic

check function Response has bare the following format:

{"status":"success"}

or , in case of error :

{"status":"failure"}

• healthcheck docker installation

  Each microservice docer file needs to include the following command:

  HEALTHCHECK --interval=30s --timeout=5s CMD curl --fail http://localhost:3000/healthcheck || exit 1

• The helthcheck docker service is expected to get 200 or 500 http status response

Please note* - All injections within the scanned folders (/src/services, /src/repositories, /src/routes) can be used implicitely - no need to get the instance from the container Example: the makeAPI function is a part of routes and hence scanned into the container. It can implicitly use userService, which is scanned as a part of services folder (notice the destructuring of the parameter):

function makeAPI({ usersService }) {
//...
}

Configuration

Configuration is done both at the module level and the child app level. Add /config folder to your root, and default. and production. (type can be virtually any configuration format), where production overrides the default values when in production mode (NODE_ENV is 'production') Usage: inject the config service in the constructor

constructor({configService})
//...
this.config.get('someKey')
this.config.get('logger.someKey')

Dependencies

• Koa2 - The returned app is a standard koa application, which can be used with middlewares as usual (see https://www.npmjs.com/package/koa2)