Unity Multiplayer UnityWebRequest does not work on Linux dedicated server

I'm posting this here in the hopes of getting more visibility compared to the Linux forum since I'm assuming this could affect anyone running dedicated servers.

Calling UnityWebRequest on Linux results in "Network Error: Unknown Error" and Status Code "0". Making this same call on windows works fine and returns Status Code "200".

I've attempted to use System.Net.WebClient instead but that results in a certificate error, even on windows. Overriding ServerCertificateValidationCallback to always return true does allow me to send the request on both Windows and Linux, but I assume that is not a valid or safe solution.

After some googling it appears UnityWebRequest does not work on all Linux platforms due to potential issues with locating certificates. I can only confirm this does not work on Amazon Linux but it could potentially affect all non Ubuntu versions.

Is there a solution for sending Http requests from a Linux dedicated server?

 

Sorry for delay getting back on this. Also please correct me if I say something wrong, the only bits I know about Http requests is what I've scraped together trying to debug this over the last couple days.

As for http vs https test results:

Amazon Linux (GameLift) - UnityWebRequest.Get("http://www.google.com") returns Status Code "200". So all good there.
Amazon Linux (GameLift) - UnityWebRequest.Get("https://www.google.com") returns Status Code "0" and "Network Error: Unknown Error".

Now I was originally using UnityWebRequest.Post() but I'm assuming if Get fails Post will as well. I just wanted to eliminate my specific URL from the potential variables.

Unfortunately I don't think using Http is an option. Its a 3rd party server I have to send the post request to and they require Https as far as I can tell. I did attempt to use http but it was blocked. I'm assuming overriding the cert validation callback as I did before is probably the same as sending plain http, even though it's fooling into thinking it's https? It's a work around at least.

I'm still looking into the environment variables and proxy settings. I'm not sure if I have access to those with GameLift so I'm waiting to hear back. I'll let you know as soon as I hear anything.

 

Do you have any suggestions on how to go about symLinking? I'd prefer if there is something I could include in the Unity project itself, but most solutions I find seem to be executed through Linux command line.

 

Unity v2018.2.11f1

 

Success! I was able to create the symLink through an install.sh shell script. I can now send Https requests using UnityWebRequest().

For anyone that is interested here is the shell script "install.sh" I ended up with:

Code (CSharp):

1. #!/bin/bash
2. sudo chmod 755 install.sh
3. sudo mkdir -p /etc/ssl/certs
4. cd /etc/ssl/certs
5. sudo ln -s /etc/pki/tls/certs/ca-bundle.crt /etc/ssl/certs/ca-certificates.crt
6.  

Also Notepad++ has a handy option to make the text file compatible by cleaning up some of the white space. Under the Edit Menu -> EOL Conversion -> UNIX /OSX Format

Thanks for the help!

 

Thank you so much!

 

Localhost request:

For Ubuntu 20.04.5 LTS
$ sudo ln -s /etc/ssl/certs/ca-certificates.crt /usr/local/share/ca-certificates/ca-bundle.crt
sudo update-ca-certificates