Currently virtlogd has a hardcoded max file size of 128kb
and max of 3 backups. This adds two new config parameters
to /etc/libvirt/virtlogd.conf to let these be customized.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
For logging one-shot entries to the VM log file it's quite a waste to
hold open the file descriptor for logging that is provided by the
current API.
This new API will be ideal for logging one-shot entries to the file
e.g. at the point when we shut the VM down rather than having to add the
whole file-descriptor infrastructure.
Additionally this will allow to add the messages even after restart of
libvirtd since virtlogd doesn't allow to obtain a regular context with
filedescriptors while the VM is still active.
The virtlogd daemon currently opens all files for append, but
in some cases the user may wish to discard existing data. Define
a new flag to indicate that logfiles should be truncated when
opening.
The virtlogd RPC messages all have a flags parameter. For
sake of future error reporting we should be verifying
these are all 0 for now.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The current virtlogd RPC protocol provides the ability to
handle log files associated with QEMU stdout/err. The log
protocol messages take the virt driver, domain name and
use that to form a log file path. This is quite restrictive
as it prevents us re-using the same RPC protocol messages
for logging to char device backends where the filename
can be arbitrarily user specified. It is also bad because
it means we have 2 separate locations which have to decide
on logfile name.
This change alters the RPC protocol so that we pass the
desired log file path along when opening the log file
initially. Now the virt driver is exclusively in charge
of deciding the log filename
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The virtlogd daemon is launched with a 30 second timeout for
unprivileged users. Unfortunately the timeout is only inhibited
while RPC clients are connected, and they only connect for a
short while to open the log file descriptor. We need to hold
an inhibition for as long as the log file descriptor itself
is open.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Define a new RPC protocol for the virtlogd daemon that provides
for handling of logs. The initial RPC method defined allows a
client to obtain a file handle to use for writing to a log
file for a guest domain. The file handle passed back will not
actually refer to the log file, but rather an anonymous pipe.
The virtlogd daemon will forward I/O between them, ensuring
file rotation happens when required.
Initially the log setup is hardcoded to cap log files at
128 KB, and keep 3 backups when rolling over, which gives
a max usage of 512 KB per guest.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
