nginx configuration showing two pads, one hosted on a subdir and one on /

[jkbzh]

This is a complement to the discussion I started about updating the nginx proxy setup in the wiki. You'll find here below an overall view of a configuration where you have a test pad hosted on the '/test' subdir and a production pad hosted on '/', both of them hosted on the server pad.example.org. I skipped some parts related to the specific server setup, such as ssl . All other nginx configuration parts related to etherpad fully. I tested this configuration.

Each pad is setup with two sections, one that handles socket.io/ for websocket requests and another one for all the other requests to the pad. Note that due to the way that nginx process location sections, the socket.io section must always precede the other section. For the same reason, the sections related to the pad hosted on '/' must be the last ones.

Finally, there's a specific setup for the HTTP Connection and Upgrade sections. Both of these headers are needed in HTTP/1.1 for a websocket upgrade (see mdn. Here I show a specific setup recommended by the nginx developers for websockets upgrade, where the HTTP Upgrade header is made dependent on the presence of the HTTP Connection: upgrade header and value, as required by the protocol.

Compared to what's in the wiki, there are two changes:

• the section that handles socket.io is distinct from the one handling the other requests to the pad, regardless of whether the pad is hosted at '/' or on a subdir. This section is also the only one that allows the upgrade to websockets. This is what is shown in the apache setup on the same wiki page.
• for the pad that is hosted on a subdir, the section that that handles the non socket.io/ requests to the pad (/test/p/foo, /test/admin/, ...) takes care of checking that the URL ends with a / when needed by means of regular expressions and rewrites. This is in contrast to the wiki where each different request type is shown in its own Location, even when the headers are the same. Of course, if you need to have specific treatment for some of those requests, like e.g., for the /admin ones, you can make them a separate section.

http {
  ...

    # Make the value of a "Connection" header depend on the presence of an
    # "Upgrade" header and value in the client's request headers.  See
    # https://nginx.org/en/docs/http/websocket.html
    map $http_upgrade $connection_upgrade {
      default upgrade;
      ''       close;
    }
}

server {
  server_name  pad.example.org;

  # test pad hosted on /test and listening on port 9002
    
  location ~ ^/test/socket.io(?:/|$) {
    rewrite ^/test/socket.io$ /test/socket.io/ permanent;
    rewrite ^/test/(.*) /$1 break;
    proxy_pass            http://127.0.0.1:9002;
    proxy_read_timeout    1d;
    proxy_connect_timeout 90s;
    proxy_send_timeout    90s;
    proxy_redirect        / /test/;
    proxy_http_version    1.1;
    proxy_buffering       off;
    proxy_set_header      Connection "upgrade";
    proxy_set_header      Upgrade $http_upgrade;
    proxy_set_header      X-Forwarded-For $remote_addr;
    proxy_set_header      X-Forwarded-Proto $scheme;
    proxy_set_header      X-Proxy-Path /test;
  }
  
  location ~ ^/test(?:/|$) {
    rewrite ^/test$ /test/ permanent;
    rewrite ^/test/admin$ /test/admin/ permanent;
    rewrite ^/test/admin-auth$ /test/admin-auth/ permanent;
    rewrite ^/test/static$ /test/static/ permanent;
    rewrite ^/test/(.*) /$1 break;
    proxy_pass            http://127.0.0.1:9002;
    proxy_read_timeout    1d;
    proxy_connect_timeout 90s;
    proxy_send_timeout    90s;
    proxy_redirect        / /test/;
    proxy_http_version    1.1;
    proxy_buffering       off;
    proxy_set_header      X-Forwarded-For $remote_addr;
    proxy_set_header      X-Forwarded-Proto $scheme;
    proxy_set_header      X-Proxy-Path /test;
  }

  # production pad hosted on / and listening on port 9001

  location ~ ^/socket.io(?:/|$) {
    rewrite ^/socket.io$ /socket.io/ permanent;
    proxy_pass            http://127.0.0.1:9001;
    proxy_read_timeout    1d;
    proxy_connect_timeout 90s;
    proxy_send_timeout    90s;
    proxy_http_version    1.1;
    proxy_buffering       off;
    proxy_set_header      Connection $connection_upgrade;
    proxy_set_header      Upgrade $http_upgrade;
    proxy_set_header      X-Forwarded-For $remote_addr;
    proxy_set_header      X-Forwarded-Proto $scheme;
  }

  location / {
    proxy_pass            http://127.0.0.1:9001/;
    proxy_read_timeout    1d;
    proxy_connect_timeout 90s;
    proxy_send_timeout    90s;
    proxy_http_version    1.1;
    proxy_buffering       off;
    proxy_set_header      Connection "upgrade";
    proxy_set_header      Upgrade $http_upgrade;
    proxy_set_header      X-Forwarded-For $remote_addr;
    proxy_set_header      X-Forwarded-Proto $scheme;
  }

}