This module is being renamed to express-autoserve.

Autodetect the service platform and delegate to an Express app.

Usage

const expressAutoserve = require('express-autoserve');
const app = require('./app');

expressAutoserve(app);

Mechanics

req.baseUrl

The node http module has no concept of baseUrl because it assumes it will get to open the TCP socket itself and just serve out pages at /. However, various deployment strategies supported by autoserve are commonly used to deploy applications at URIs other than /. Thus autoserve provides a getBaseUrl(req) function to discover the baseUrl for the current request (in FastCGI, the necessary information is not available until a request is received).

Express supports mounting applications at sub-paths. To enable mounted applications to generate absolute URIs to resources within the apps, it provide the req.baseUrl property. This enables the following to work sensibly:

const express = require('express');

const app = express();

const subApp = express();
subApp.get('/asdf', function (req, res) {
   // When mounted, will get /subApp/foo
  res.send(`Another resource on this app is ${req.baseUrl}/foo`);
});
subApp.get('/foo', function (req, res) {
  res.send(`You found me!`);
});

app.use('/subApp', subApp);
app.listen(3000);

This module ensures that the passed app is treated like it is mounted in an express app at the baseUrl calculated by autoserve. This causes the baseUrl to be set properly for the passed app and ensures that routing is performed relative to the deployment baseUrl.