Proxy based on user agent headers

[shelbyt]

Can I route based on the user-agent header? For example, if a header comes in with googlebot I want to route the bot to a different url. I only see Context and Path matching in the docs.

[chimurai]

You can have a look at the router option:

https://github.com/chimurai/http-proxy-middleware/blob/master/recipes/router.md#custom-router-function

createProxyMiddleware({
  target: 'http://localhost:8000',
  router: function (req) {
    // if googlebot (implement googlebot detection using the req object)
    return 'http://www.example.org'; // different target
  },
})

[shelbyt]

Thank you. I'll try that.

What's the difference between that approach you've shown and this one in the docs using custom matching?:

const filter = function (pathname, req) {
  return pathname.match('^/api') && req.method === 'GET';
};

const apiProxy = createProxyMiddleware(filter, {
  target: 'http://www.example.org',
});

[chimurai]

Those are really two different properties.

filter will call express' next function to skip further processing.
router allows you to assign a different target, it's will proxy the call eventually