I have a custom setup where I'm using the Guacamole Guacd proxy and client side api to connect to servers using RDP. This works great. However, every 59th attempt the connection simply fails. No new connections can be made before I restart the container running guacd. After the restart I can connect for another 59 times before the pattern repeats.
When checking the logs I can see the following errors:
SSL_CTX_new failed
transport_connect_tls:freerdp_set_last_error_ex ERRCONNECT_CONNECT_CANCELLED [0x0002000B]
as well as
DEBUG: Major bug, unable to allocate a TLS value for currentThread
The last error is from FreeRDP (which Guacamole uses to handle the RDP integration) - but I can't figure out if this causes the error or if it's a consequence of the SSL_CTX_new error.
From the source code for FreeRDP it could look like something doesn't get released - and then at some point it's not possible to get a TLS thread: https://github.com/FreeRDP/FreeRDP/blob/87557b1e4ef636e18a7dea58f0cae76fa5dff4fb/winpr/libwinpr/thread/thread.c#L439
However - I can't figure out if this is caused by something in FreeRDP or if it's a result of the SSL_CTX_new failure. It could also be limitations in server / Docker configuration - but I have no idea where to start looking.
Could anyone help me figure out why this is failing?
I'm running guacd 1.5.4 on Docker on an Ubuntu 20.04.
UPDATE
Running this on guacd 1.5.3 seems to resolve the issue, so a change between 1.5.3 and 1.5.4 seems to be causing this.