Custom Nginx Configuration is written outside location block causing invalid config

[maveice]

Bug Description

When using the Custom Nginx Configuration feature in the Advanced settings (⚙️) of a proxy host, NPMplus writes the custom configuration outside the location / block, resulting in invalid nginx syntax and failed configuration tests.

Affected Version

• NPMplus Version: 2026-01-17-r2 (likely affects other recent versions)
• Image: zoeyvid/npmplus:latest

Steps to Reproduce

1. Create a proxy host (e.g., example.com)
2. Navigate to Details tab and configure:
   • Domain: example.com
   • Forward Hostname: 192.168.1.x
   • Forward Port: xxxx
3. Go to Advanced settings (⚙️ gear icon)
4. Add Custom Nginx Configuration, for example:

# WebSocket Support
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";

# Custom Headers
proxy_set_header Host $host;
proxy_buffering off;

5. Save the configuration
6. Check generated config file in /data/nginx/proxy_host/xxx.conf

Expected Behavior

Custom nginx directives should be placed inside the location / block:

server {
    server_name example.com;
    # ... server config ...
    
    location / {
        include proxy-headers.conf;
        
        # ✅ Custom config HERE (inside location block)
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_set_header Host $host;
        proxy_buffering off;
        
        proxy_pass http://192.168.1.x:xxxx;
    }
}

Actual Behavior

Custom nginx directives are placed outside the location / block:

server {
    server_name example.com;
    # ... server config ...
    
    location / {
        include proxy-headers.conf;
        proxy_pass http://192.168.1.x:xxxx;
    }
    # custom locations
    
    # ❌ Custom config HERE (outside location block - INVALID!)
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";
    proxy_set_header Host $host;
    proxy_buffering off;
    
    # Custom
    include /data/custom_nginx/server_proxy.conf;
}

Impact

1. Nginx configuration test fails for certain directives that are only valid inside location blocks (e.g., proxy_http_version, proxy_set_header, proxy_buffering)
2. Services fail to work properly even if nginx starts, because proxy directives are not applied
3. Manual intervention required: Users must manually edit the generated .conf files to move directives inside the location block
4. Configuration gets overwritten: Any manual fixes are lost when the host is updated via GUI

Error Messages

$ docker exec npmplus nginx -t
nginx: [emerg] "proxy_http_version" directive is not allowed here in /data/nginx/proxy_host/xxx.conf:XX
nginx: configuration file /usr/local/nginx/conf/nginx.conf test failed

Affected Use Cases

This bug particularly affects configurations for:

• Nextcloud AIO (requires WebDAV headers and chunked uploads)
• Plex Media Server (requires WebSocket support)
• Immich (requires large upload timeouts and buffering settings)
• Code-Server (requires specific host headers and WebSockets)
• Any service requiring custom proxy directives

Workaround

Users must manually edit the generated config files:

# Edit the generated config
sudo nano /data/nginx/proxy_host/xxx.conf

# Move all custom directives from after "# custom locations" 
# into the location / block

# Test and reload
docker exec npmplus nginx -t
docker exec npmplus nginx -s reload

Note: This workaround is temporary and gets overwritten on next GUI update.

Additional Context

• This appears to be a regression as the comment in generated configs states: # DO NOT EDIT THIS FILE DIRECTLY, CHANGES WILL BE LOST WHEN UPDATING!
• The issue occurs regardless of whether directives are valid at server-level or require location-level
• Some directives like client_max_body_size can work at server-level, but proxy-specific directives cannot

Suggested Fix

The template engine generating the nginx configuration should place custom nginx configuration inside the location / block, not after it. Alternatively:

1. Add a validation check that warns users about directives that must be inside location blocks
2. Provide separate fields for "Server-Level Custom Config" vs "Location-Level Custom Config"
3. Auto-detect directive types and place them in the correct context

Related Configurations

This bug does not affect:

• Custom Locations (those work correctly)
• Host-level settings like client_max_body_size (if placed correctly)

---

Environment:

• Platform: Docker
• NPMplus Version: 2026-01-17-r2
• Image: zoeyvid/npmplus:latest
• Nginx Version: (embedded in NPMplus)

[Zoey2936]

no I will not talk to AI

[maveice]

Hello Zoey, I asked Claude to help me on this as I love your new npmplus version, as I could't write it that precise. I am sorry, iI didn't mean to upset you with that.
I would very much appreciate if you could kindly let me know, how I can fix it.

Many thanks, Michael

[Zoey2936]

Either ask AI or me, I don't discuss with AI. If you don't know what you're doing then don't input anything in the advanced tab/custom configs. WebSockets are always enabled in NPMplus. For Nextcloud AIO I even provided screenshots in their reverse proxy guide.

[maveice]

Dear Zoey,

sorry for the confusion. Let me describe the actual problem I'm experiencing (in my onw words):

When I add custom nginx directives in the Advanced tab (gear icon),
the configuration ends up outside the location / block in the generated
.conf file, which causes nginx test to fail.

Example: I need to set specific headers for my service, but when I add:

• proxy_set_header Host my-domain.com
• proxy_buffering off

These appear after the location / block closes, not inside it.

Is this the expected behavior, or should I configure this differently?

Thanks,
Michael

[Zoey2936]

yes this is expected behaviour. For proxy_buffering this is fine (I'm adding a button to faster trigger this), but why do you want to override the host header? NPMplus already sets it correctly

[maveice]

I now fully understand the way NPMplus works - so many things are now already implemented "right out of the box" 😃
Yes, please still add a button for "proxy_buffering".

Thanks a lot fpr this great piece of development!