proxycache's Introduction

proxycache

A simple, configurable, Redis-powered caching proxy.

Use it when you want to

deliver a URL to a static file
cache the file somewhere
provide a URL to the cached version for subsequent requests

Install

$ npm install --save proxycache

Example

const express = require('express')
const request = require('request')
const proxycache = require('proxycache')

// Create Redis/Cloud Storage proxycache client
const config = {
  store: {
    client: 'redis',
    connection: {}
  },
  cache: {
    client: 'gcloud',
    connection: {
      keyFilename: './gcloud-key.json',
      projectId: 'my-project-id'
    },
    options: {
      bucket: 'images'
    }
  }
}
let cache
proxycache(config).then(client => {
  cache = client
})

// Image server to proxy for
const imgsrv = express()
imgsrv.get('/images/:id', (req, res) => {
  const id = req.params.id
  request.get(`http://www.fillmurray.com/g/${id}/${id}`).pipe(res)
})
imgsrv.listen(3888)
console.log('Image server listening on 3888')

const render = src => `
<html>
  <head>
   <title>bfm</title>
  </head>
  <body>
   <img src='${src}' height=500 width=500/>
  </body>
</html>
`

// API Server
const app = express()
app.get('/images/:id', (req, res) => {
  const id = req.params.id
  // query the cache
  cache.get(id).then(result => {
   // cache hit
    if (result) {
      return res.end(render(result))
    }
    const uri = `http://localhost:3888/images/${id}`
   // cache miss; send the default url
    res.end(render(uri))
   // cache the file; TTL in seconds
    cache.set(id, uri, 60)
  })
})
app.listen(8000)