Re: qemu+ssh connections to a remote libvirt fail as ssh banner configured
On Thu, Feb 10, 2022 at 17:47:43 +0800, Yalan Zhang wrote: > Thank you! I tried /etc/motd, and it does not impact the libvirt connection. > Happy to learn something new! Alternatively if you really need to run commands in .bashrc which can potentially print some output, you can put them after a check for interactive shell: if [[ $- != *i* ]] ; then # Shell is non-interactive. Be done now! return fi echo "Interactive shell here. How are you?" Jirka
Re: qemu+ssh connections to a remote libvirt fail as ssh banner configured
Thank you! I tried /etc/motd, and it does not impact the libvirt connection.
Happy to learn something new!
On Thu, Feb 10, 2022 at 4:50 PM Daniel P. Berrangé
wrote:
> On Thu, Feb 10, 2022 at 09:33:38AM +0100, Michal Prívozník wrote:
> > On 2/10/22 09:02, Daniel P. Berrangé wrote:
> > > On Thu, Feb 10, 2022 at 09:52:52AM +0800, Yalan Zhang wrote:
> > >> Hi there,
> > >>
> > >> I have a system configured with ssh login banner like as below:
> > >> # cat ~/.bashrc
> > >> ...
> > >> echo
> > >>
> "="
> > >> echo "== This machine is occupied by xxx for testing now. If you
> are
> > >> about to use it, contact xxx first =="
> > >> echo
> > >>
> "="
> > >>
> > >> It works as expected that whenever someone logs into this system by
> ssh,
> > >> he/she will see this warning message.
> > >> But it seems such settings will impact a virsh client connection with
> ssh,
> > >> when I try to connect the libvirt daemon on this system, it will
> error out :
> > >> # virsh -c qemu+ssh://${my_host}/system list --all
> > >> root@${my_host}'s password:
> > >> error: failed to connect to the hypervisor
> > >> error: packet 1027423545 bytes received from server too large, want
> 33554432
> > >
> > > Libvirt is tunnelling an RPC protocol over the SSH connection.
> > > Your bashrc is printing this text onto the SSH conmnection and
> > > that corrupts the libvirt RPC protocol.
> > >
> > > If you want to print something whjen people login use the
> > > /etc/motd file which is designed for this pupose, don't
> > > print stuff from a .bashrc. Libvirt gives the options to
> > > SSH that prevent display of /etc/motd contents, so that
> > > its RPC protocol doesn't get corrupted.
> >
> > One more thing, I wasn't able to reproduce when virt-ssh-helper was
> > used. But maybe I wasn't trying hard enough.
>
> That should be affected in exactly the same way. It still relies on
> stdout/stdin being clean data channels.
>
> Regards,
> Daniel
> --
> |: https://berrange.com -o-
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> https://www.instagram.com/dberrange :|
>
>
Re: qemu+ssh connections to a remote libvirt fail as ssh banner configured
On Thu, Feb 10, 2022 at 09:33:38AM +0100, Michal Prívozník wrote:
> On 2/10/22 09:02, Daniel P. Berrangé wrote:
> > On Thu, Feb 10, 2022 at 09:52:52AM +0800, Yalan Zhang wrote:
> >> Hi there,
> >>
> >> I have a system configured with ssh login banner like as below:
> >> # cat ~/.bashrc
> >> ...
> >> echo
> >> "="
> >> echo "== This machine is occupied by xxx for testing now. If you are
> >> about to use it, contact xxx first =="
> >> echo
> >> "="
> >>
> >> It works as expected that whenever someone logs into this system by ssh,
> >> he/she will see this warning message.
> >> But it seems such settings will impact a virsh client connection with ssh,
> >> when I try to connect the libvirt daemon on this system, it will error out
> >> :
> >> # virsh -c qemu+ssh://${my_host}/system list --all
> >> root@${my_host}'s password:
> >> error: failed to connect to the hypervisor
> >> error: packet 1027423545 bytes received from server too large, want
> >> 33554432
> >
> > Libvirt is tunnelling an RPC protocol over the SSH connection.
> > Your bashrc is printing this text onto the SSH conmnection and
> > that corrupts the libvirt RPC protocol.
> >
> > If you want to print something whjen people login use the
> > /etc/motd file which is designed for this pupose, don't
> > print stuff from a .bashrc. Libvirt gives the options to
> > SSH that prevent display of /etc/motd contents, so that
> > its RPC protocol doesn't get corrupted.
>
> One more thing, I wasn't able to reproduce when virt-ssh-helper was
> used. But maybe I wasn't trying hard enough.
That should be affected in exactly the same way. It still relies on
stdout/stdin being clean data channels.
Regards,
Daniel
--
|: https://berrange.com -o-https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org -o-https://fstop138.berrange.com :|
|: https://entangle-photo.org-o-https://www.instagram.com/dberrange :|
Re: qemu+ssh connections to a remote libvirt fail as ssh banner configured
On 2/10/22 09:02, Daniel P. Berrangé wrote:
> On Thu, Feb 10, 2022 at 09:52:52AM +0800, Yalan Zhang wrote:
>> Hi there,
>>
>> I have a system configured with ssh login banner like as below:
>> # cat ~/.bashrc
>> ...
>> echo
>> "="
>> echo "== This machine is occupied by xxx for testing now. If you are
>> about to use it, contact xxx first =="
>> echo
>> "="
>>
>> It works as expected that whenever someone logs into this system by ssh,
>> he/she will see this warning message.
>> But it seems such settings will impact a virsh client connection with ssh,
>> when I try to connect the libvirt daemon on this system, it will error out :
>> # virsh -c qemu+ssh://${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.
Michal
Re: libvirtd daemon missing in LFS
On Thu, Feb 10, 2022 at 11:39:17 +0530, Sai Kiran Kumar Reddy wrote: > Hi, > > There was some issue with pkg-config-path. I have fixed it. I see that it > looks for wireshark and other dependencies. I get an error saying "remote > driver is required for libvirtd daemon". I am not sure what this error So you are missing some of the dependencies needed by the remote driver which is needed for the libvirtd daemon. Similarly to what I've suggested before can be used for any other option. To list full configuration of the project along with options that were selected you can run 'meson configure' from the builddir and it will print all options: $ meson configure [... snipped ... ] Project optionsCurrent ValuePossible Values Description ------- --- apparmor auto [enabled, disabled, auto]apparmor support apparmor_profiles auto [enabled, disabled, auto]install apparmor profiles attr auto [enabled, disabled, auto]attr support audit auto [enabled, disabled, auto]audit support bash_completionauto [enabled, disabled, auto]bash-completion support bash_completion_dir directory containing bash completion scripts blkid auto [enabled, disabled, auto]blkid support capng auto [enabled, disabled, auto]cap-ng support ch_group groupname to run Cloud-Hypervisor system instance as ch_user username to run Cloud-Hypervisor system instance as chrdev_lock_files location for UUCP style lock files for character devices (leave empty for default paths on some platforms) curl auto [enabled, disabled, auto]curl support docdir documentation installation directory docs auto [enabled, disabled, auto]whether to generate documentation driver_bhyve auto [enabled, disabled, auto]bhyve driver driver_ch auto [enabled, disabled, auto]Cloud-Hypervisor driver driver_esx auto [enabled, disabled, auto]esx driver driver_hyperv auto [enabled, disabled, auto]Hyper-V driver driver_interface auto [enabled, disabled, auto]host interface driver driver_libvirtdauto [enabled, disabled, auto]libvirtd driver driver_libxl auto [enabled, disabled, auto]libxenlight driver driver_lxc auto [enabled, disabled, auto]Linux Container driver driver_network auto [enabled, disabled, auto]virtual network driver driver_openvz auto [enabled, disabled, auto]OpenVZ driver driver_qemuauto [enabled, disabled, auto]QEMU/KVM driver driver_remote auto [enabled, disabled, auto]remote driver driver_secrets auto [enabled, disabled, auto]local secrets management driver driver_testauto [enabled, disabled, auto]test driver driver_vboxauto [enabled, disabled, auto]VirtualBox XPCOMC driver driver_vmware auto [enabled, disabled, auto]VMware driver driver_vz auto [enabled, disabled, auto]Virtuozzo driver dtrace auto [enabled, disabled, auto]use dtrace for static probing expensive_testsauto [enabled, disabled, auto]set the default for enabling expensive tests (long [...] > means. Does it mean that I have to install wireshark or is it looking for No wireshark is optional, only if you want to build the dissector for the libvirt protocol as plugin into wireshark. > something else. Could you please help me out here. So
Re: qemu+ssh connections to a remote libvirt fail as ssh banner configured
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.
Regards,
Daniel
--
|: https://berrange.com -o-https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org -o-https://fstop138.berrange.com :|
|: https://entangle-photo.org-o-https://www.instagram.com/dberrange :|
