Systemd does not forget about the cases, where client service needs to
wait for daemon service to initialize and start accepting new clients.
Setting a dependency in client is not enough as systemd doesn't know
when the daemon has initialized itself and started accepting new
clients. However, it offers a mechanism to solve this. The daemon needs
to call a special systemd function by which the daemon tells "I'm ready
to accept new clients". This is exactly what we need with
libvirtd-guests (client) and libvirtd (daemon). So now, with this
change, libvirt-guests.service is invoked not any sooner than
libvirtd.service calls the systemd notify function.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=1031696
When creating a new domain, we let systemd know about it by calling
CreateMachine() function via dbus. Systemd then creates a scope and
places domain into it. However, later when the host is shutting
down, systemd computes the shutdown order to see what processes can
be shut down in parallel. And since we were not setting
dependencies at all, the slices (and thus domains) were most likely
killed before libvirt-guests.service. So user domains that had to
be saved, shut off, whatever were in fact killed. This problem can
be solved by letting systemd know that scopes we're creating must
not be killed before libvirt-guests.service.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Previous commit
commit 7ada155cdf
Author: Gao feng <gaofeng@cn.fujitsu.com>
Date: Wed Sep 11 11:15:02 2013 +0800
DBus: introduce virDBusIsServiceEnabled
Made the cgroups code fallback to non-systemd based setup
when dbus is not running. It was too big a hammer though,
as it did not check what error code was received when the
dbus connection failed. Thus it silently ignored serious
errors from dbus such as "too many client connections",
which should always be treated as fatal.
We only want to ignore errors if the dbus unix socket does
not exist, or if nothing is listening on it.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The problem is described by [0] but its effect on libvirt is that
starting a container with a full distro running systemd after having
stopped it simply fails.
The container cleanup now calls the machined Terminate function to make
sure that everything is in order for the next run.
[0]: https://bugs.freedesktop.org/show_bug.cgi?id=68370
https://bugzilla.redhat.com/show_bug.cgi?id=1008619
1,003 bytes in 1 blocks are definitely lost in loss record 599 of 635
==404== by 0x50728A7: virBufferAddChar (virbuffer.c:185)
==404== by 0x50BC466: virSystemdEscapeName (virsystemd.c:67)
==404== by 0x50BC6B2: virSystemdMakeSliceName (virsystemd.c:108)
==404== by 0x50BC870: virSystemdCreateMachine (virsystemd.c:169)
==404== by 0x5078267: virCgroupNewMachine (vircgroup.c:1498)
This patch introduces virDBusIsServiceEnabled, we can use
this method to get if the service is supported.
In one case, if org.freedesktop.machine1 is unavailable on
host, we should skip creating machine through systemd.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
On hosts that don't have the DBus service running or installed the new
systemd cgroups code failed with hard error instead of falling back to
"manual" cgroup creation.
Use the new helper to check for the system bus and use the fallback code
in case it isn't available.
There are some interesting escaping rules to consider when dealing
with systemd slice/scope names. Thus it is helpful to have APIs
for formatting names
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
If systemd machine does not exist, return -2 instead of -1,
so that applications don't need to repeat the tedious error
checking code
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
To register virtual machines and containers with systemd-machined,
and thus have cgroups auto-created, we need to talk over DBus.
This is somewhat tedious code, so introduce a dedicated function
to isolate the DBus call in one place.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
