@infect/rda-service/src/Server.js

Microservice Framework for RDA

import HTTP2Server from '@distributed-systems/http2-server';
import logd from 'logd';
import PortFinder from 'get-available-port';



const log = logd.module('Server');




export default class Server {



    constructor({
        serviceName,
        allowCors,
    } = {}) {
        this.serviceName = serviceName;

        this.server = new HTTP2Server({
            secure: false,
        });

        this.allowCors = allowCors;

        // add middlewares
        this.addMiddlewares();

        // get port from args
        const portConfig = process.argv.find(item => item.startsWith('--port='));
        this.port = portConfig ? parseInt(portConfig.substr(7), 10) : false;

        this.portFinder = new PortFinder();
    }





    /**
    * register middlewares on the server
    */
    addMiddlewares() {

        // set the service name on the response
        if (this.serviceName) {
            this.server.registerMiddleware(async (request) => {
                request.response().setHeader('x-rda-service', this.serviceName);
            });
        }

        // add english as default language
        this.server.registerMiddleware(async (request) => {
            if (request.hasHeader('accept-language')) {
                request.setHeader('accept-language', request.getHeader('accept-language') + ',en; q=.1');
            } else {
                request.setHeader('accept-language', 'en; q=.1');
            }
        });

        // cors
        this.server.registerMiddleware(async (request) => {
            const headers = [];

            if (this.allowCors === true) {
                headers.push(['Access-Control-Allow-Origin', request.getHeader('origin') || '*']);

                if (request.method('options')) {
                    headers.push(['Access-Control-Allow-Methods', request.getHeader('access-control-request-method') || 'GET, OPTIONS']);
                    headers.push(['Access-Control-Allow-Headers',  request.getHeader('access-control-request-headers') || '']);
                    headers.push(['Access-Control-Allow-Credentials', request.getHeader('access-control-request-credentials') ||  'true']);
                }
            } else if (this.allowCors === false) {
                // do nothing
            } else {
                // old questionable code
                headers.push(['Access-Control-Allow-Origin', request.getHeader('origin')]);
                headers.push(['Access-Control-Allow-Methods', 'GET, OPTIONS']);
                headers.push(['Access-Control-Allow-Headers', 'select, filter']);
                headers.push(['Access-Control-Allow-Credentials', 'true']);

            }


            request.response().setHeaders(headers);

            if (request.method('options')) {
                log.debug('Sent reponse for OPTIONS request');
                request.response().status(204).send();
                return false;
            }
        });
    }




    /**
    * start the web server, use the port passed by the --port argv
    * or the port passed to the function or a random free port
    */
    async listen(port) {
        this.port = this.port || port || await this.portFinder.getPort();

        await this.server.listen(this.port);

        log.info(`Server is listening on port ${this.port}`);
        return this.port;
    }





    /**
    * shut down the server
    */
    async close() {
        await this.server.close();
    }




    /**
     * return the servers router
     *
     * @return     {router}  The router.
     */
    getRouter() {
        return this.server.getRouter();
    }




    /**
    * returns the express app
    */
    getServer() {
        return this.server;
    }
}