Device details not showing

[antamy]

Just managed to get NetAlertx running in a Proxmox LXC. All of my devices are discovered. If I click on one I get the device details tab and a Loading message with a spinning icon. The Details never load. I don't see any errors in the log. How would I troubleshoot this?

[jokob-sk]

Hi,

Please post browser console logs: https://docs.netalertx.com/DEBUG_API_SERVER/?h=console

[antamy]

Not exactly sure what you are looking for, but here are errors that I see:

[NetAlertX State] Retry 1/3... sse_manager.js:132:15
[NetAlertX State] Connected to SSE sse_manager.js:64:15

and

Uncaught TypeError: response.find is not a function
    success http://10.10.10.58:20211/js/modal.js?v=unknown:465
    jQuery 6
    checkNotification http://10.10.10.58:20211/js/modal.js?v=unknown:455
    setInterval handler* http://10.10.10.58:20211/js/modal.js?v=unknown:585

Browser is Firefox on Windows, and the same occurs with Edge.

I did try the API directly:

curl -X 'GET' \
  'http://10.10.10.58:20212/device/b0%3A5a%3Ada%3A20%3A07%3Ab7' \
  -H 'accept: application/json'

and received:

{
  "error": "Forbidden",
  "message": "ERROR: Not authorized",
  "success": false
}

[jokob-sk]

Maybe post screenshots as there might be something else... here is how a correct load looks like:

You are getting this because you need to authorize the call:

{
  "error": "Forbidden",
  "message": "ERROR: Not authorized",
  "success": false
}

See: https://docs.netalertx.com/API/?h=api

You can also access the API docs on <server>:GRAPHQL_PORT/docs

[jokob-sk]

Also, please collaborate here if you got it working on LXC - would be grateful: #1516

[antamy]

ok, the authorized api brings back a good amount of detail. I don't see any 200 GETs of type JSON from the Devices > My Devices > Details page. Just this:

[jokob-sk]

Please filter the requests with the keyword "period" as in my screenshot above.

[antamy]

I did, nothing shows up.

…

________________________________ From: "Jokob @netalertx" ***@***.***> Sent: Sunday, March 22, 2026 18:08 To: netalertx/NetAlertX Cc: Anthony R. Roby; Author Subject: Re: [netalertx/NetAlertX] Device details not showing (Discussion #1571) Please filter the requests with the keyword "period" as in my screenshot above. — Reply to this email directly, view it on GitHub<#1571?email_source=notifications&email_token=ABUGFTV6AHRFFNXNCQVINCD4SBXAFA5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCNRSGY2DEMZQUZZGKYLTN5XKMYLVORUG64VFMV3GK3TUVRTG633UMVZF6Y3MNFRWW#discussioncomment-16264230>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/ABUGFTSEUZ2KP56AS7DFFEL4SBXAFAVCNFSM6AAAAACW2XZUROVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTMMRWGQZDGMA>. You are receiving this because you authored the thread.Message ID: ***@***.***>

[jokob-sk]

Can you try manually deleting the notification history - should be located under /tmp/api/user_notifications.json and/or replace teh file content with []

[antamy]

I deleted it and refreshed the page. No change.

[jokob-sk]

replace teh file content with []

[antamy]

Makes no difference. Still stuck on Loading..

[jokob-sk]

Also post a screenshot of the Response of this API call:

[antamy]

I never see those calls. Everything is of type html, except these 2:

[antamy]

[jokob-sk]

Click on it and screenshot the Response tab:

Like so:

[antamy]

I just don't see the status 200 lines, just 302.

[jokob-sk]

Not sure why this is happening - maybe nginx related? It should give an 200 response - not sure how nginx is handled in LXC

[antamy]

I set Claude on it and it identified the problem pretty much straight away. It's some nginx mapping issue:

Issue: Device Details Never Load (302 / 404 from nginx)

After the initial fix guide, the application loads and devices are discovered, but clicking a device in the list causes the UI to hang. Browser DevTools shows requests to /server/device/<mac> and /server/sse/state returning 302 or 404.

Root cause: The default netalertx.conf has no proxy blocks for the Python backend (Flask/FastAPI on port 20212). All requests hit the location / block and are served by PHP. Additionally, the frontend prepends /server/ to API calls, but the backend mounts routes without that prefix — so the proxy must strip /server/ before forwarding.

---

Fix: Update netalertx.conf

Replace /app/config/netalertx.conf with the following:

server {
    listen 20211;
    server_name _;
    root /var/www/html/netalertx;
    index index.php;
add_header X-Forwarded-Prefix "/netalertx" always;
charset utf-8;

# Proxy /server/* to Python backend, stripping the /server/ prefix
location /server/ {
    proxy_pass http://127.0.0.1:20212/;
    proxy_http_version 1.1;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Prefix "/netalertx";
    proxy_read_timeout 300;
}

# Proxy /api/* to Python backend, stripping the /api/ prefix
location /api/ {
    proxy_pass http://127.0.0.1:20212/;
    proxy_http_version 1.1;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Prefix "/netalertx";
    proxy_read_timeout 300;
}

location / {
    try_files $uri $uri/ /index.php?$query_string;
}

location ~ \.php$ {
    fastcgi_pass unix:/var/run/php/php-fpm.sock;
    fastcgi_index index.php;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    fastcgi_param PATH_INFO $fastcgi_path_info;
    fastcgi_param QUERY_STRING $query_string;
    include fastcgi_params;
}

}

⚠️ The trailing slash on proxy_pass http://127.0.0.1:20212/; is critical — it tells nginx to strip the matched location prefix before forwarding. Without it, /server/sse/state is passed to the backend as-is and returns 404 because the backend mounts routes at /sse/state, not /server/sse/state.

Then reload nginx:

nginx -t && systemctl reload nginx

---

Additional Root Causes (for maintainers)

These should be added to the install script:

| Fix needed

-- | --
1 | Move nginx enable/restart to after netalertx.conf is written
2 | Install from root requirements.txt, not install/proxmox/requirements.txt
3 | Create /data/ symlinks pointing to /app/config, /app/db, /tmp/log, /tmp/api
4 | Create /tmp/api and /tmp/log with www-data ownership (and recreate on boot)
5 | Add www-data sudoers entry for /usr/sbin/arp-scan
6 | Add /server/ and /api/ proxy blocks to netalertx.conf with prefix stripping

[antamy]

I'm thinking something isn't installed correctly or is missing.

[jokob-sk]

IDK what you did, I don't use LXC and don't actively support it due to these kind of issues