fake-cgi

Tiny cgi-like server for JS-files

The Idea

When I switched from PHP to JS development (long time ago) I was missing that one feature where you could just have a bunch of unrelated PHP-files in different directories on the server that would only run when needed.

Now I created a simple server with Node that runs JS-files server-side on demand. The benefit is, I don't need a running Node instance for every script that might only really be used once in a while.

Example Usage

GET and a searchquery parameter

// script.cgi.js

const param = decodeURI(process.argv[2] || '')
if (param === 'action1') {
  // ...
} else {
  // ...
}

console.log('success')

// call with
// $ curl 'http://localhost:1234/script.cgi.js?action1'

POST with JSON data

// api.cgi.js

function api (json) {
  // ...
  return { success: true, data: '...' }
}

let body = ''
process.stdin.on('data', (data) => {
  body += data.toString()
})
process.stdin.on('end', () => {
  // stderr will be parsed as headers (if possible)
  console.error('Content-Type: application/json')
  try {
    const json = JSON.parse(body)
    console.log(JSON.stringify(api(json)))
  } catch (e) {
    console.log(JSON.stringify({ success: false, error: e.toString() }))
  }
})

// call with
// $ curl 'http://localhost:1234/api.cgi.js' --data '{"query":"..."}'

Configuration

Environment Variables

There are some environment variables that can be set:

• BASEDIR the base directory that contains the script files
• PORT the port

What you could do / Things you can change

In the main Node script that runs the server you can modify the default extension .cgi.js to fit your needs. By default the maximum execution time of scripts is limited to 10 seconds.

You could also tell the script to run bash scripts etc.

Nginx

To work on the default port that static html files are also served under, I configured nginx like this:

server {
  # ...

  index index.cgi.js index.html;

  # ...

  location ~* .*\.cgi\.js {
    proxy_pass http://localhost:8989;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection 'upgrade';
    proxy_set_header Host $host;
    proxy_cache_bypass $http_upgrade;
  }
}

map $http_upgrade $connection_upgrade {
  default upgrade;
  '' close;
}