Nginx proxy_pass to remote file

Question

I have an nginx server where I'd like to point any route that begins with /app to a specific file. It's a single page app, so even /app/some/long/route should just return the same index.html file.

location /app {
    proxy_pass http://my-cdn-host.com/index.html;
}

I'm having 2 problems:

1. I'm pretty sure that /app/very/long/url does a proxy_pass to http://my-cdn-host.com/index.html/app/very/long/url which is not wanted
2. It's not clear to me based on the logs exactly what the proxied URL is, so I can't even fully confirm the point above. $proxy_host and $upstream_addr don't have that full information

One final note: even though the file is http://my-cdn-host.com/index.html, I'm unable to access it with just http://my-cdn-host.com/. The index.html needs to be the explicit path.

Is there a way I can serve a single remote file for my location? Thank you

Answer 1

This is exactly the expected behavior, described in the proxy_pass directive documentation:

If the proxy_pass directive is specified with a URI, then when a request is passed to the server, the part of a normalized request URI matching the location is replaced by a URI specified in the directive:

location /name/ {
    proxy_pass http://127.0.0.1/remote/;
}

You need to use another proxy_pass behavior feature, described somewhat below:

In some cases, the part of a request URI to be replaced cannot be determined:

...

• When the URI is changed inside a proxied location using the rewrite directive, and this same configuration will be used to process a request (break):

  location /name/ {
      rewrite    /name/([^/]+) /users?name=$1 break;
      proxy_pass http://127.0.0.1;
  }
  

  In this case, the URI specified in the directive is ignored and the full changed request URI is passed to the server.

Use the following location block:

location /app {
    rewrite ^ /index.html break;
    proxy_pass http://my-cdn-host.com;
}