csync SSL fails with csync2[1452]: SSL: handshake failed: Certificate is required. (GNUTLS_E_CERTIFICATE_REQUIRED) #38
Description
At least on ubuntu 20.04 with gnutls 3.6.13-2ubuntu1.6 SSL connections fail with GNUTLS_E_CERTIFICATE_REQUIRED error in syslog even when everything is otherwise correctly configured. Adding nossl allows for sync to work. I straced the process to see that it does indeed read the certificates and otherwise works as it should, however something must have been updated in gnutls so that it throws a message that csync2 cannot handle.
easily reproducible with ie. following config
group replicated
{
host host1;
host host2;
key /etc/csync2.d/csync2_clusterkey.key;
include /opt/replicated;
action
{
pattern /opt/replicated;
exec "/usr/bin/systemctl restart nginx";
do-local;
}
backup-directory /opt/replicated-backup;
backup-generations 3;
auto none;
}