server.js

const newrelic = require('newrelic');
require('@newrelic/koa');
const Koa = require('koa');
const Router = require('@koa/router');
const KoaSwagger = require('koa2-swagger-ui');
const pino = require('pino');
const nrPino = require('@newrelic/pino-enricher');
const logger = require('koa-pino-logger')({
  logger: pino(nrPino()),
  serializers: {
    req: (req) => {
      const { headers, ...rest } = req;
      return rest;
    },
    res: (res) => {
      const { headers, ...rest } = res;
      return rest;
    },
  }
});
const aggregator = require('swagger-aggregator');
const fs = require('fs');

const proxy = require('./middleware/proxy');
const apiversion = require('./middleware/apiversion');
const auth = require('./middleware/auth');

const superheroes_protocol = process.env.SUPERHEROES_SERVICE_PROTOCOL || "http"
const superheroes_host = process.env.SUPERHEROES_SERVICE_HOST || "superheroes"
const superheroes_port = process.env.SUPERHEROES_SERVICE_PORT || "5000"

const customers_protocol = process.env.CUSTOMERS_SERVICE_PROTOCOL || "http"
const customers_host = process.env.CUSTOMERS_SERVICE_HOST || "customers"
const customers_port = process.env.CUSTOMERS_SERVICE_PORT || "5010"

const authEnabled = (process.env.AUTH_ENABLED === "true") || false

const app = new Koa();

const router = new Router();

//set up the swagger docs
template = fs.readFileSync(`${__dirname}/swagger/aggregator.tpl.yml`)
resolved = template.toString()
  .replace('${superheroes_host}', superheroes_host)
  .replace('${superheroes_port}', superheroes_port)
  .replace('${customers_host}', customers_host)
  .replace('${customers_port}', customers_port);
fs.writeFileSync('swagger/aggregator.yml', resolved);
aggregator('swagger/aggregator.yml')
  .then(result => {
    fs.writeFileSync('swagger/api.json', JSON.stringify(result));
    const spec = JSON.parse(fs.readFileSync(`${__dirname}/swagger/api.json`));
    app.use( 
      KoaSwagger.koaSwagger({
        routePrefix: "/docs",
        specPrefix: "/docs/swagger.json",
        swaggerOptions: {
          url: "/docs/swagger.json",
          spec,
        },
        hideTopbar: false,
        exposeSpec: true }));
  });

router.redirect("/", "/docs");
 
router.get('/ping', (ctx, next) => {
  ctx.body = {
    message: "healthy"
  }
});

router.use('/api/:version/(.*)', apiversion);

const authUrl = `${customers_protocol}://${customers_host}:${customers_port}/v2/customers/authorize`
router.all('apiProxy', '/api/(.*)', auth(authEnabled, authUrl), proxy({
  '/api/(.*)/superheroes(.*)': `${superheroes_protocol}://${superheroes_host}:${superheroes_port}/$1/superheroes$2`,
  '/api/(.*)/customers(.*)': `${customers_protocol}://${customers_host}:${customers_port}/$1/customers$2`
}));

app
  .use(logger)
  .use(router.routes())
  .use(router.allowedMethods());

const port = process.env.HTTP_PORT || 3000

app.listen(port, () => {
  logger.logger.info(`app listening on port ${port}`);
})