koa-varnish

The cache middleware for koa, it can cache the data such as varnish. The cache ttl is use the value of s-maxage or maxage from response header: Cache-Control.

Uncacheable list:

• Method isn't 'GET' or 'HEAD'
• Function isCacheable return false
• HTTP response status is not 200, 203, 204, 300, 301, 302, 304, 307, 404, 410, 414
• Get max-age form response header Cache-Control isn't gt 0

Installation

$ npm i koa-varnish

API

• hash Get the key for the cache, default is ${ctx.method}-${ctx.url}
• isCacheable Check the request is cacheable, default is all true.
• cache The opotions for lru-cache
• hitForPass The max-age for hit for pass, default is 300 * 1000ms

const cache = require('koa-varnish');
const Koa = require('koa');
const app = new Koa();

app.use(cache({
  hash: ctx => ctx.url,
  isCacheable: (ctx) => {
    if (ctx.url.indexOf('/user') === 0) {
      return false;
    }
    return true;
  },
}));

app.use(ctx => {
	if (ctx.url === '/wait') {
    return new Promise(function(resolve, reject) {
      ctx.set('Cache-Control', 'private, max-age=10');
      ctx.body = 'Wait for 1000ms';
      setTimeout(resolve, 1000);
    });
	} else {
    ctx.set('Cache-Control', 'public, max-age=10')
    ctx.body = 'Hello World';
	}
});

License

MIT