rest-api-starter/app/server.js

Rest API starter kit.

/**
 * Created by svinci on 8/18/16.
 */
'use strict';

const express = require('express');
const bodyParser = require('body-parser');
const cookieParser = require('cookie-parser');
const compression = require('compression');
const configuration = require('config');
const uuid = require('uuid');

const localStore = require('./local-store');
const logger = require('./logger')('server-initialization');

const configureLoggingFilter = (app) => {
    const transactionHeaderName = configuration.get('app.http.transactionHeader');

    app.use((request, response, next) => {
        localStore.create(() => {
            const transactionId = request.get(transactionHeaderName) || uuid.v4().substr(0, 7);
            response.append(transactionHeaderName, transactionId);

            localStore.putValue('req', request);
            localStore.putValue('res', response);
            localStore.putValue('tid', transactionId);

            logger.info(`Received request ${request.method} at ${request.url}`);
            next();
        });
    });
};

const configureCompression = (app) => {
    const compressionEnabled = configuration.has('app.http.compression') ? configuration.get('app.http.compression') : true;
    if (compressionEnabled) {
        app.use(compression());
    }
};

const configureCookieParser = (app) => {
    const cookieParserEnabled = configuration.has('app.http.cookies') ? configuration.get('app.http.cookies') : true;
    if (cookieParserEnabled) {
        app.use(cookieParser(configuration.get('app.http.secret')));
    }
};

const configureJsonBodyParser = (app) => {
    const jsonBodyParserEnabled = configuration.has('app.http.json') ? configuration.get('app.http.json') : true;
    if (jsonBodyParserEnabled) {
        app.use(bodyParser.json());
    }
};

const configureNotFoundHandler = (app, customNotFoundHandler) => {
    const defaultNotFoundHandler = (req, res) => {
        logger.warn(`Returning 404 for url: ${req.url}.`);
        res.status(404).send({
            'status': 404,
            'message': 'url/method combination not found',
            'detail': {
                'url': req.url,
                'method': req.method
            }
        });
    };
    app.use(customNotFoundHandler || defaultNotFoundHandler);
};

const configureErrorHandler = (app, customErrorHandler) => {
    const defaultErrorHandler = (err, req, res, next) => {
        if (err.name === 'validation.error') {
            logger.error(err.name);
            res.status(400).send({
                'status': 400,
                'message': err.name,
                'detail': err.errors
            });
        } else if (err.name && err.name === 'document.not.found') {
            logger.error(err.message);
            res.status(404).send({
                'status': 404,
                'message': err.message,
                'detail': err.detail
            });
        } else {
            logger.error(`Unhandled error for request ${req.method} at ${req.url}. Err: ${err}.`);
            res.status(500).send({
                'status': 500,
                'message': 'unhandled error',
                'detail': err.toString()
            });
        }
    };
    app.use(customErrorHandler || defaultErrorHandler);
};

const newServer = (router, customNotFoundHandler, customErrorHandler) => {
    logger.info('Starting server...');
    const start = new Date();
    const app = new express();

    configureLoggingFilter(app);
    configureCompression(app);
    configureCookieParser(app);
    configureJsonBodyParser(app);
    router(app);
    configureNotFoundHandler(app, customNotFoundHandler);
    configureErrorHandler(app, customErrorHandler);

    const port = configuration.get('app.http.port');
    const host = configuration.get('app.http.host');
    const queue = configuration.get('app.http.queue');

    return app.listen(port, host, queue, () => {
        logger.info(`Server started in ${new Date() - start}ms`);
        logger.info(`Listening on port ${port} and host ${host}. Queue: ${queue}`);
    });
};

module.exports = newServer;