Hardcoded path /p breaks pad exports

[arieljlira]

Hi, I have an etherpad-lite instance behind a reverse proxy with an alternative path to my pads, "/pads" instead of "/p". All work fine, except the export functionality. Export routes are "/null/export/$format" and the worst is that it works! because it always returns the pad named "null" ...

How to reproduce it? reverse proxy an instance with a route other than /p/ . Like

        RewriteRule ^/pads/(.*)$ http://localhost:9001/p/$1 [P]
        RewriteCond %{REQUEST_FILENAME} !-f
        RewriteRule ^/(.*)$ http://localhost:9001/$1 [P]

I think the problem is in https://github.com/ether/etherpad-lite/blob/develop/src/static/js/pad_impexp.js#L210 Replacing RegExp

var pad_root_path = new RegExp(/.*\/p\/[^\/]+/).exec(document.location.pathname);

with

var pad_root_path = new RegExp(/.*\/[^\/\?]+/).exec(document.location.pathname);

seems to fix the problem. I've tested in and with this patch, export routes works as expected with /p, /pads, /some/other/route and /some/other/route?with=params

I saw a similar report in https://bugs.launchpad.net/openstack-ci/+bug/1168455

Thanks!

[JohnMcLear]

Your fix will hurt instances that run on /p/

I think the best fix for this is prolly to use whatever function is getting the padId and use that to write the export url

Afiak i had a plugin that fixed this issue for a specific site a while back, your temp fix wont hurt you now but obviously if you pull you will have merge conflicts on that file so it will hurt you later.

[arieljlira]

Hi John, I don't know you say it will hurt instances that run on /p/ I have the same ep instance behind another proxy, with /p, and it looks fine. It also works with no proxy at all. I can send you both urls if you find it useful.

[JohnMcLear]

yea but anything else will break, for example if your etherpad was on /hosted/etherpad it wouldn't work

[arieljlira]

I've tried several routes with 2 or more levels and worked ok. For example In apache2 with mod_proxy+mod_proxy_html:

        RewriteRule ^/hosted/etherpad/pads/(.*)$ http://localhost:9001/p/$1 [P,L]
        RewriteRule ^/hosted/etherpad/(.*)$ http://localhost:9001/$1 [P]

Perhaps I'm missing something else, however regexp /.*\/[^\/\?]+/ always seems to get the correct request-uri for any uri.

I guess it would be better to a unique function to get the padId and use relative paths. But I can't help you with that because I know almost nothing about epl nor nodejs. Regards

[JohnMcLear]

Try hitup /frontend/tests when hosting EP on different endpoints with and without proxy see if anything explodes, if not send through a PR with your patch

[JohnMcLear]

I just test this using this apache config and export is working fine..

    <VirtualHost etherpadtest:80>
        ServerAdmin support@example.org
        ServerName etherpadtest
        ServerSignature Off

      Redirect /pad /pad/

    LoadModule  proxy_module         /usr/lib/apache2/modules/mod_proxy.so
    LoadModule  proxy_http_module    /usr/lib/apache2/modules/mod_proxy_http.so
    LoadModule  headers_module       /usr/lib/apache2/modules/mod_headers.so
    LoadModule  deflate_module       /usr/lib/apache2/modules/mod_deflate.so

    ProxyVia On
    ProxyRequests Off
    ProxyPass /pad/ http://localhost:9001/
    ProxyPassReverse /pad/ http://localhost:9001/
    ProxyPreserveHost on
    <Proxy *>
        Options FollowSymLinks MultiViews
        AllowOverride All
        Order allow,deny
        allow from all
    </Proxy>
    </VirtualHost>

Just don't rewrite the /p/ to something else and you will be fine..

Someone might want to go ahead and update the docs on this.

[Yaco]

I am using Nginx with this config file: https://github.com/ether/etherpad-lite/wiki/How-to-put-Etherpad-Lite-behind-a-reverse-Proxy#hosted-at--with-rewrite-rules-to-allow-padname

Export is broken if I access without "/p" in the URL. Any fix?

[JohnMcLear]

Have you looked at your nginx config?

[JohnMcLear]

See https://github.com/MozillaFoundation/mofo-lightsaber/issues/12#issuecomment-72710349 & https://github.com/MozillaFoundation/mofo-lightsaber/issues/11#issuecomment-73773049

Looks like adding something like rewrite ^/(.*)/export/(.*) /p/$1/export/$2 break; will fix this. Please test and let me know @Yaco

Also please fix your own reverse proxy configs, it's really not up to the foundation to maintain third party software for you!

[JohnMcLear]

I put a fix in for export URLS, please pull latest develop and test.