Rewrite requests without redirects

You might want to rewrite requests so they’re served by specific sections of your app without having to redirect users. For example, you might want to make URLs seem semantic to users without having to rewrite your app architecture.

In such a case, you might want requests to /shoes/great-shoe/ to be served as if they were requests to /?category=shoes&product=great-shoe. If so, add a rule similar to the following:

web:
  locations:
    '/':
      ...
      rules:
        '^/(?<category>[^/]+)/(?<product>[^/]+)/$':
          passthru: '/?category=$category&product=$product'

Or you might organize your images by file type, but don’t want to expose the organization externally. You could rewrite requests to do that behind the scenes:

web:
  locations:
    '/':
      ...
      rules:
        '^/img/(?<name>.*)\.(?<type>.*)$':
          passthru: '/$type/$name.$type'

Now a request to /img/image.png returns the file found at /png/image.png.

Query parameters

Query parameters in the request are unaffected and are passed in the request to the app. So if you have the category and product rule from previously, a request to /shoes/great-shoe/?product=terrible-shoe is rewritten to ?category=shoes&product=great-shoe&product=terrible-shoe. In that case, the product query parameter returns as terrible-shoe.