[cgmanager-devel] new 0.10 release

Serge Hallyn serge.hallyn at ubuntu.com
Fri Jan 10 22:35:51 UTC 2014


Two major changes are in the newest cgmanager sources.  First, the *Scm
dbus handlers now return as soon as the server receives the unix fd.
After this the client sends the SCM_CREDS over the unix fd, and the
result from the server is also returned over the unix fd.  This has two
major advantages:  first, the manager is never waiting synchronously on
the client, so clients can't DOS other clients.  Second, the
libcgmanager stubs for *scm functions should actually be useful, though
the caller needs to continue with the transaction after calling the
library function.  (Note however that it is greatly encouraged to NOT
use *Scm methods;  those exist for the cgproxy to use.)

The second major change is that the socket has been moved to
/sys/fs/cgroup/manager/sock.  Previously it was /sys/fs/cgroup/manager,
and that socket file was bind-mounted into a container.  This meant that
when the manager on the host restarted, the bind mount source was the
old socket.  Containers could only recover by stopping and restarting.
Now the /sys/fs/cgroup/manager/ directory can be bind-mounted into the
container, so that the proxy in the container can simply re-open the
file 'sock' in that directory if the manager restarts.

This is now tagged as v0.10 at github.com/cgmanager/cgmanager;  a make dist
tarball is at http://people.canonical.com/~serge/cgmanager-0.10.tar.gz;
ubuntu trusty package source is at lp:~serge-hallyn/+junk/cgmanager; and
a 0.10-1 package is at ppa:serge-hallyn/userns-natty.


More information about the cgmanager-devel mailing list