Nginx Proxy Manager suddenlynot working

Apps and Virtualization
1

Hi all!
I was using Nginx Proxy Manager for a year i think, and like a week ago, when i decided to upgrade all of my apps on my truenas system, it went crazy.
It means, every of my app is working, running (checked by hostip:port, they are actually working), but NONE of my proxies defined on NPM working.

I got instant HTTP 521 errors as reply, when i tries to load the pages from a browser.

Once again. First i bulk updated all my apps on my truenas server (that time i was on 24.X. (i think 24.4 but not sure)
The app updates were successfull, but then i realized that i was unable to reach my sites. My first action was to update my OS as well to the latest.
I did it in 2 steps. First i updated to 24.10, then 25.04.0, and here im at this moment on this version.

Again checked, everything is working, running, no error, but when i tries to open my sites over internet (with my cname.domain.hu) then it gives me instant HTTP 521.

Also i recognised my home assistant VM gone. As it turned out there were a big change with the OS regarding virtualization, which i didn’t know. Luckily i had my vm on a separate zvol , so that is not a problem now.

My problem is why am i getting suddenly the HTTP521 errors? Were there any network related change on the system?

I spent my last 4 night trying to find a solution, but no success.
Tried to set up 100x port forwards on my router and test them (for example with a python server).
Tried to set up like 3 new instance of NPM.
My last try was installind Traefik.

I think i configured everything well, yet i get 521 errors.
Almost forget to mention that my domain is managed by cloudflare
My dns settings (A, cnames) are set to proxied, and SSL setting to FULL strict. As it was for the previous year, and nobody touched it.
It can be also usefull information that on NPM i can renew an SSL certificate for one of my proxy. So the communication, and the API key is also (should be) correct.

Any hint where should i look for?
Thank you in advance!

2

When you updated all your apps, did they change what docker network they were running on? I know nginx needs the apps to be on the same network, so an ip 172.16.1.1 ans 172.16.1.2 would work fine but 172.16.1.1 and 172.16.2.4 would not. I had a similar issue when 1st getring started with nginx, worth a go.

3

You are absolutelly right, and i highly appretiate your comment.
To be honest, i checked it before, so i know that all of my apps are on DIFFERENT network.
So you are correct.

But since on npm ui, on a proxy host edit section i used the host ip (for all of the apps), i tought the internal docker ip for each app is irrelevant.

But it is worth a try, i will add then to the same network.
What were the exact steps you have made?

Is that possible that previously all of my apps were on the same network, and for some reason, after the update they got their own network for some reason?

4

No problem, happy to (try) and help, to be honest, until about October last year I’d never used containers, it has been a steep learning curve, I dont see why any ip would have changed when you updated but then stranger things have happend,

I use Portainer for my container management, just prefer the layout, in it I can go into each container and manually select which network it is on (although these days I found out you can specify the network in the yaml file so been doing that with the more recent ones).

Hope you get it sorted, and I’ve not lead you down a wild goose chase.

5

So i tried, but unfortunatelly no success.
I deleted every one of nginx installations. I created a brand new one.
I added the new nginx and for example radarr to the same network.
Then i added a new proxy to npm.

To the host ip i tried to add my truenas host ip first (as it was like for a year!)
-No success!
I tried DNS names from the radarr container
Like “ix-radarrnew-radarr-1”
-No success

I tried with the IP of the running radarr container
-No success.

So i don’t know what the hell is goind on.
I was wondering if any kind of firewall on truenas kicks in to block my request from outside, so it does not even reach npm, so it cannot route to radarr, but as i read it, in theory there is no such a thing like truenas firewall.

I created a new docker with a simple debian, where is installed curl. From that docker i was able to curl my running radarr app
-by its dockers DNS name,
-by my host ip:port

So there is connection between the dockers!
If i get this working again, i never ever will do an update (which is not good , because it is a risk by itself… :S )

6

Ohh just 1 more thing that I thought off, again prob isnt an issue, but when I was configuring nginx, i had to manually change the webui ports of truenas away from 80/443 so that nginx cpuld listen on these ports

Any chance something similar happening here?

8

That is already done.
Truenas base ports were changed to custom like 2 years ago.

Now the current instance of npm uses a custom port, and i do port forwarding on my router.

But i tried to have an npm installation which listens on the normal 80/443 ports , no success.

In every case i do port forward, i did not forget it.
The port forward functionality is also tested, and it works.

9

Any luck? I foolishly just did the same thing today (mass upgraded all apps) but did not upgrade my OS, and have had nothing but 521s since from NGINX.

10

Have you tried setting it to use the host network?
I have this set in the additional environment variables section.

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