index.js

import bodyParser from 'body-parser';
import { create as createDomain } from 'domain';
import express from 'express';
import swaggerUi from 'swagger-ui-express';
import YAML from 'yamljs';
import config from './config.js';
import apiRoutes from './lib/api.js';
import { getLogger } from './lib/logger.js';
import adapterDetails from './src/adapterDetails.js';

const swaggerDocument = YAML.load('./reference/sync-adapter.v1.yaml');
const logger = getLogger({ module: 'index.js' });
const app = express();
app.use(
    bodyParser.urlencoded({
        extended: true
    })
);
app.use(bodyParser.json());

let reqId = 0;
app.use((req, res, next) => {
    const externalSystem = req.headers[adapterDetails.getExternalSystemIdentificationHeaderName()];
    if (req.path === '/api/health') {
        next();
        return;
    }
    req.reqId = reqId++;
    if (externalSystem) {
        logger.action(
            req.method +
                ' [' +
                req.reqId +
                '] ' +
                req.path +
                ' (Master: ' +
                req.headers.x_master_uri +
                ', ES: ' +
                externalSystem +
                ')'
        );
    } else {
        logger.action(req.method + ' [' + req.reqId + '] ' + req.path + ' (Master: ' + req.headers.x_master_uri + ')');
    }
    next();
});

// error handling
app.use(function (req, res, next) {
    // create a domain for this request
    let domain = createDomain();

    // handle errors on this domain
    domain.on('error', function (err) {
        logger.error('[' + req.reqId + '] DOMAIN ERROR CAUGHT');
        console.dir(err);
        try {
            try {
                // attempt to use Express error route
                next(err);
            } catch (error) {
                // if Express error route failed, try plain Node response
                logger.error('[' + req.reqId + '] Express error mechanism failed.\n', error.stack);
                res.statusCode = 500;
                res.setHeader('content-type', 'text/plain');
                res.end('Server error.');
            }
        } catch (error) {
            logger.error('[' + req.reqId + '] Unable to send 500 response.\n', error.stack);
        }
    });

    // add the request and response objects to the domain
    domain.add(req);
    domain.add(res);

    // execute the rest of the request chain in the domain
    domain.run(next);
});

app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(swaggerDocument));

app.use('/', apiRoutes);

app.listen(config.port, err => {
    if (err) {
        return logger.error('Sync adapter: something bad happened', err);
    }

    logger.info(`Sync adapter is listening on ${config.port}`);
    return true;
});