Nginx Reverse Proxy settings

I am in the process of setting up a server configuration which consists of

• A front end server running Nginx. Call it example.com

• Another server, also running Nginx, (on the same network and accessible via an internal IP, say 10.118.10.9) which runs - amongst other things - phpRedisAdmin.

• The front end server has a reverse proxy configuration that goes like this

  location ^~ /admin/ { proxy_pass https://10.118.0.9:8085/; }

Now when I browse to `https://example.com/admin/redisadmin/index.php'

The Memcache Admin page turns up just right. An examination of console logs shows now errors. I then proceed to click the Add Another Key link which brings up the phpMemcachedAdmin edit form. When I examine the code for this form I see

<form action="/redisadmin/edit.php?s=0" method="post">

Now if I enter a key name, a value and click on the Add button in the form the browser attempts to post to

https://example.com/redisadmin/edit.php?s=0

which promptly throws up a 404 since the action URL for the form should in fact have been

<form action="/admin/redisadmin/edit.php?s=0" method="post">

Somewhere along the way the /admin bit got lopped off. I suspect that this is down to invalid Nginx reverse proxy settings. However, I am a novice when it comes to this so I have no idea how I should correct the problem.

Have checked the page of redis admin and found it reads the request URI from server side, which means it will include the leading slash '/' in the URL for the post form:

<form action="<?php echo format_html($_SERVER['REQUEST_URI'])?>" method="post">

You have the remove the leading slash in php so you can post to correct address when access via reverse proxy. However, as a workaround, you can rewrite the URL in nginx to fix it.

location / {
    rewrite ^/redisadmin/(.*)$ /admin/redisadmin/$1 last;

Add the above rewrite rule to your setting in '/' seciton, see if it works.