Re: qemu+ssh connections to a remote libvirt fail as ssh banner configured

On 2/10/22 09:02, Daniel P. Berrangé wrote: > On Thu, Feb 10, 2022 at 09:52:52AM +0800, Yalan Zhang wrote: >> Hi there, >> >> I have a system configured with ssh login banner like as below: >> # cat ~/.bashrc >> ... >> echo >> "=================================================================================" >> echo "====== This machine is occupied by xxx for testing now. If you are >> about to use it, contact xxx first ======" >> echo >> "=================================================================================" >> >> It works as expected that whenever someone logs into this system by ssh, >> he/she will see this warning message. >> But it seems such settings will impact a virsh client connection with ssh, >> when I try to connect the libvirt daemon on this system, it will error out : >> # virsh -c qemu+ssh://${my_host}/system list --all >> root@${my_host}'s password: >> error: failed to connect to the hypervisor >> error: packet 1027423545 bytes received from server too large, want 33554432 > > Libvirt is tunnelling an RPC protocol over the SSH connection. > Your bashrc is printing this text onto the SSH conmnection and > that corrupts the libvirt RPC protocol. > > If you want to print something whjen people login use the > /etc/motd file which is designed for this pupose, don't > print stuff from a .bashrc. Libvirt gives the options to > SSH that prevent display of /etc/motd contents, so that > its RPC protocol doesn't get corrupted. One more thing, I wasn't able to reproduce when virt-ssh-helper was used. But maybe I wasn't trying hard enough.