app.js

#!/usr/bin/env node

import "native-injects";
import yargs from "yargs";
import http from "http";
import {createApp} from "./src";
import path from "path";

const argv = yargs.usage('Usage: $0 <command> [options]')
                .version(process.env.npm_package_version || "UNKNOWN")

                .option("environment", {
                    description: 'The environment this is running in.'
                })

                .option("port", {
                    description: 'The port to bind to.',
                    type: "number"
                })

                .option("host", {
                    description: 'The hostname to bind to.'
                })

                .option("config", {
                    description: 'The config file.'
                })
                .option("rules-config", {
                    description: 'The rules config file.'
                })
                .option("verbose", {
                    description: "More detailed logging",
                    alias: "v",
                    boolean: true
                })

                .argv;


function startServer(app, context) {
    const config = context.config.server;

    const port = process.env.PORT || config.port;
    const host = process.env.HOST || config.host;

    app.set('port', port);
    app.set('host', host);

    const server = http.createServer(app);

    server.listen(port, host);
    server.on('error', error => {
        if (error.syscall !== 'listen') {
            throw error;
        }

        if (error.code === "EACCES") {
            context.logger.error({port, host}, "Requires elevated privileges");
            process.exit(1);
            return;
        } else if (error.code === "EADDRINUSE") {
            context.logger.error({port, host}, "Address already in use");
            process.exit(1);
            return;
        }
        throw error;
    });
    server.on('listening', () => {
        context.logger.info({port, host}, "Listening");
    });
}


function run(args) {

    const environment = args.environment || process.env.NODE_ENV || "development";

    const defaultConfigPath = path.join(__dirname, "config");
    const configFile = args.config || path.join(defaultConfigPath, environment);
    const config = require(configFile).default;
    config.server.host = args.host || config.server.host;
    config.server.port = args.port || config.server.port;
    config.logging.stdoutLevel = args.verbose ? "debug" : config.logging.stdoutLevel;


    const rulesFile = args.rulesConfig || path.join(defaultConfigPath, config.rules || "rules");
    const rulesConfig = require(rulesFile).default;

    const {app, context} = createApp(environment, config, rulesConfig);
    context.logger.debug({
        config: configFile,
        environment,
        host: config.server.host,
        port: config.server.port
    }, "Starting");

    startServer(app, context);
}
run(argv);