cachinate

Fetches an asset, adding cache headers

Usage

var middleware = cachinate(headers, [end])

• headers (object) - headers to merge into into res.headers
• [end] (boolean) - Whether the middleware has the responsibility of ending the request. Defaults to false. If you set this to true, make sure the requests will have a query string parameter called asset and holding a URL.
• returns (function) middleware - merges the provided headers into res.headers.

const cachinate = require('cachinate')

const middleware = cachinate({
  'cache-control': 'public, no-transform, max-age=31540000'
  'Edge-Control': '!no-cache, max-age=31540000'
})
app.use(middleware)
app.use(function (req, res, next) {
  assert(res.headers['cache-control'] === 'public, no-transform, max-age=31540000')
  assert(res.headers['Edge-Control'] === '!no-cache, max-age=31540000')
})

npm start

Launches a production-ready http server using this middleware and expecting the following query string parameters to be provided with each request (preferably via urlinate):

• asset {string} - Required! URL of asset to GET and stream back as response)
• [headers] {object} - Optional. headers to be merged into res.headers

There are also default headers, see defaultHeaders.js

Examples

The following examples suppose there is a cachinator running at http://cachinator.cdn. As the URL suggests, this could also be the URL of a CDN having a cachinator as origin server. This is a nice way to allow shared caching between clients who share the same edge server.

By default, cachinate will add headers to cache for a year

var urlinate = require('urlinate')
var url = urlinate('http://cachinate.cdn', {
  asset: 'http://wtv.com/asset.jpg'
})
http.get(url, function (res) {
  // res.headers['cache-control'] === 'public, no-transform, max-age=31540000'
  // res.headers['Edge-Control'] === ''!no-cache, max-age=31540000'
})

But you can override the default cache duration by setting those headers to something different. In fact, you can just set any headers you want

var urlinate = require('urlinate')
var url = urlinate('http://cachinator.cdn', {
  asset: 'http://wtv.com/asset.jpg',
  headers: {
    'cache-control': `no-cache`,
    'Edge-Control': 'no-cache',
    'X-Proxy-User-Agent': 'Cachinator!!!'
  }
})
http.get(url, function (res) {
  // res.headers['cache-control'] === 'no-cache'
  // res.headers['Edge-Control'] === 'no-cache'
  // res.headers['X-Proxy-User-Agent'] === 'Cachinator!!!'
})

Deployment

now

See nowjs.org

Also works out of the box on Heroku

git remote add <your_heroku_remote>
git push heroku master