VPN tunnel for apps

[Lonkle]

Okay, after hardcode exposing ALL internal ports of the OpenVPN container, now the last thing is adding a second nginx reverse proxy which would mean this:

My exposedPort for the Gucamole app I'm installing to connect to the OpenVPN Client app exposes 8080. It gets a Docker internal httpPort of 32455. Nginx already correctly creates a nginx proxy config from web incoming port 80 and 443 to 32455 (somehow, presumably DNS TXT records, it even gets an SSL cert).

So, I need to have nginx after that continue to proxy it to 8080. Which normally is Docker's job (with it's binding port) but when connecting two container's networks together, it doesn't do that job with the dockerode library for some Docker-y reason. I wonder...can I reverse proxy it in the same file as the original reserve proxy server. Or do I have to create a .conf and an entirely new one?

[Lonkle]

If I have the same nginx reverse proxy "listen" to it's own forwarded port (32455), then I could proxy_pass again to the real internal port and IP (8080) of Guacomole (the test app I'm now using to connect to the vpn client app)...or maybe I need another reverse proxy residing at Internal-IP-of-Guacomole:32455 to then proxy_pass again to 8080.

[robi]

The problem there is that the stuff in the container doesn't have access outside the container, so it's hard to drop updates to the host Nginx as another .conf file.

You could tell box to do it via how it already happens for new apps. Must be an API for it.

[Lonkle]

@robi I keep trying to experiment on how to shoehorn a second Ngnix proxy into this to get it all up and running 100% with no success.

Inter-communication between the two containers would be nice, but tbh I could hardcode that if I knew how to setup the second reverse nginx inside of reverseproxy.js. Which, honestly, I can't figure out how.

[robi]

maybe we need a few more eyes from @nebulon @girish @mehdi for more options

[Lonkle]

I know the answer lies here:

https://git.cloudron.io/cloudron/box/-/blob/master/src/reverseproxy.js#L463

I can configure a second file for a second nginx server to proxy app.httpPort to app.manifest.httpPort - but, like, I don't know how to change that it's hardcoded to listen only on 80 and 443. Plus, I don't know how to actually get this hypothetical second nginx reverse proxy running to "take" the new config within the container that's connecting to the VPN. But that's the last step here on how to make this work.

[mehdi]

@mehdi said in VPN tunnel for apps:

(Disclaimer: I am no expert on docker networking magic)

I think instead of trying to find a way to expose the ports from the OpenVPN container, you should instead try and find a way to make it work directly from the app container itself.

Even if you do make it work for the exposedPort (which, I think, refers to the main web port exposed by the app, the one which is behind the reverse proxy, to expose its web interface and such, that's why there's only one: there's only one web interface), you're gonna have trouble with the extra ports (the ones defined in the manifest here https://docs.cloudron.io/custom-apps/manifest/#tcpports ) for apps that use these.

I really think this. You should try finding a way to make the app container's default route be through the OpenVPN network, but still be connected to cloudron's regular network so it can interact with nginx and stuff. There is no good reason to make all the traffic, even the local one, be through OpenVPN.

@Lonk is there a repo with your box changes ? Maybe I'll have time to take a look this WE

[Lonkle]

@mehdi You only have to change one file (docker.js) so I’ll send that to you today!

But the app has no other issues. It is on the Cloudron network. It has everything network-wise that the OpenVPN container has which means there are no issues anywhere. The only issue is that Nginx doesn’t take that into account because it inherits all network ports and modes from the OVPN Client it’s connected to.

I actually have an idea though to prove that everything works except the web interface using the app terminal.

I will also be sending you my OVPN client in chat so you can see how it works.

[Lonkle]

@mehdi Thanks for your willingness to help me out. You were my inspiration for working on this. Felt right since you had to dive into box code to add the NET_ADMIN capability.

[Lonkle]

@mehdi Oh, and just to make it clear, the app is running fine even in the terminal. If I install the LAMP app for instance and connect it to the OpenVPN Client. I can go to LAMP's terminal and type curl 127.0.0.1:80 and it will give me the LAMP Welcome page, but from the IP address of the OpenVPN Client. It'll just never get past the "Starting..." stage without a 200 response and Nginx is routing it to the wrong location. Maybe I could try hardcoding it to the right port after it installs it's config.

Like, this works. But I don't know how to get NGINX to route it to the port I need it to route to. Docker is supposed to bind the app.httpPort (say 34567) to the exposedPort (say 80). But that Docker binding command has to be removed to connect the containers so NGINX has to bind them manually somehow and I don't know how to work with Nginx.

[Lonkle]

I'm near positive the way to route NGINX properly is to to add another reverse proxy which leads from the Docker randomized app.http port to the exposedPort (AKA app.manifest.httpPort). I'm not sure how though. But I can clearly access the exposedPort's data from either terminal.

In the terminal of either of the two network-bonded apps (the LAMP or the VPN Client) - I can curl (localhost) the exposed ports of either app (the VPN Client or the LAMP) and get back the correct HTML pages.

It's just that the reverse proxy is forwarding it to a port that Docker wasn't allowed to bind. So with no binding, that means no NGINX web page.

[Lonkle]

For people just joining and for me to read this in the future:

Cloudron has a user-defined network cloudron that it uses for all of it's apps and services. I'm connecting my OpenVPN Client app directly to another app (LAMP for testing) using NetworkMode which is the official way to do this. When doing so, both apps share the exact same network space (including both being connected to the cloudron network) and can, in fact, even talk to each other directly (I need to set the OpenVPN Client's exposed port to something ridiculous like in the 50000s so it doesn't conflict with any regular app's commonly exposed ports - but in the end the OpenVPN Client will expose all of it's internal network ports -P for compatibility with all other apps connecting to it - but for now, this will do since I'm just testing).

Now, the NGINX Reverse Proxy resides on the main box level of Cloudron and routes to the randomized Docker binding port of the app which forwards it to it's "real" port (I honestly don't know where the IP translation takes place...I can't find it).

So, solution, place a second NGINX proxy at the randomized Docker app.http port and have that nginx server be inside of the internal network of the LAMP testing app so it can then internally forward the web request to it's exposedPort which is, also, port 80 (for LAMP anyway).

[Lonkle]

^^^^ -- Does anyone know how to do this?

[Lonkle]

@mehdi said in VPN tunnel for apps:

There is no good reason to make all the traffic, even the local one, be through OpenVPN.

All local traffic is local, it doesn't go through the VPN. All of the connected-to-the-vpn-client apps run indefinitely. Eventually after Cloudron says "Starting..." it switches the message to "Not Responding" but the app will continue indefinitely because there's nothing actually wrong with it. It's connecting to all the local services it needs, it's just, this feature was designed without consideration of Cloudron's network. That's why from within the app's terminal, I can access everything locally and everything externally (the open web) from Cloudron and the web sees my VPN Client's IP Address instead of Cloudrons. This is a perfectly running app. Except...I can't expose it's internal IP:ExposedPort to NGINX to have it actually pass the health check (meaning the web app isn't being routed to the right place and I think I need a second NGINX reverse proxy to get me routed to the app's exposed port). It gets as far as app.httpPort and then because there is no binding for the app.mainfest.httpPort (AKA: ExposedPort), it just gets stuck on the web side of things.

I can curl all I want into it the LAMP welcome. But can't access it from outside the container itself.

[Lonkle]

Quick example of all local processes running for the second container:

Oct 02 12:05:28 2020-10-02 16:05:28,718 INFO success: redis entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)
Oct 02 12:05:28 2020-10-02 16:05:28,719 INFO success: redis-service entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)
Oct 02 12:05:40 [GET] /healthcheck

It just gets stuck at the health check because NGINX is giving it a 502 Bad Gateway since port 80 is not bound to port app.httpPort. That's what I still need to figure out and I think what's best is @robi's double nginx server suggestion. I just don't know how to set up NGINX inside of the LAMP container from box code though I'm sure it's possible.

[Lonkle]

I still think the solution lies in this function:

https://git.cloudron.io/cloudron/box/-/blob/master/src/reverseproxy.js#L463

But that function is setting NGINX config listening on the server's public IP port. I need NGINX inside of the container to forward to the app.manifest.httpPort (in LAMP's case it's port 80).

Or maybe it doesn't need to be inside of the container...since if I SSH into the VPS and do curl ip-address-of-lamp:80 then it returns the HTML just fine.

[Lonkle]

SUCCESS!!!

I'm so close. I can manually edit the NGINX configuration of the LAMP-test app and get it's web app working using it's local IP (not 127.0.0.1:app.httpPort, but 172.18.0.3:80 - the port 80 is what LAMP uses). Both web pages come up for their each individual domain names. WOOOO!

It still doesn't make it past the "starting..." step though. That might be because I'm editing the NGINX file and then restarting the app to make it's web interface work. If the NGINX file was properly created from the beginning the check might pass.

[Lonkle]

Which...now I need to find the function to get the IP address of the VPN container (the app connected to it share's it's IP address).

[mehdi]

@Lonk said in VPN tunnel for apps:

@mehdi said in VPN tunnel for apps:

There is no good reason to make all the traffic, even the local one, be through OpenVPN.

All local traffic is local, it doesn't go through the VPN.

Sorry, I meant: There is no good reason to make all the traffic, even the local one, be through the OpenVPN client container.

[mehdi]

What you should try to achieve is making only the app's outgoing traffic go through OpenVPN, and the connexion between it and Nginx and stuff stay exactly the same as it currently is