Just wanted to test the Docker preview. Calling is possible but when accepting the call the message "There was a problem connecting the video call" apears. Checked the network traffic with chrom developer console and saw the problem is related with ssl. Checked the Docker preview certificate and replaced it with our own (because the preview was using a selfsigned certificate). Checked again and https requests to gateway admin are possible but websocket wss requests are not possible. Getting this error message on chrome ERR_SSL_PROTOCOL_ERROR and this one on firefox SSL_ERROR_RX_RECORD_TOO_LONG.
We reproduced this behavior on following machnes: Mac OS X, Windows 10, Android, ISO
We are using the mattermost docker image therefor db is running on postgres and mattermost is version 3.6.0.
The certificate we are using is a letsencrypt certificate.