[libvirt] [PATCH 6/9] Introduce an LXC specific public API & library

[Daniel P. Berrange]

On Tue, Jan 08, 2013 at 09:02:37AM -0700, Eric Blake wrote:
> On 12/21/2012 10:08 AM, Daniel P. Berrange wrote:
> > From: "Daniel P. Berrange" <berrange at redhat.com>
> > 
> > This patch introduces support for LXC specific public APIs. In
> > common with what was done for QEMU, this creates a libvirt_lxc.so
> > library and libvirt/libvirt-lxc.h header file.
> > 
> > The actual APIs are
> > 
> >   int virDomainLxcOpenNamespace(virDomainPtr domain,
> >                                 int **fdlist,
> >                                 unsigned int flags);
> > 
> >   int virDomainLxcEnterNamespace(virDomainPtr domain,
> >                                  unsigned int flags);
> 
> This commit message signature...

Opps, that was from a work-in-progress version of the patch.

> > +++ b/src/driver.h
> > @@ -915,6 +915,11 @@ typedef int
> >                            unsigned long long minimum,
> >                            unsigned int flags);
> >  
> > +typedef int
> > +    (*virDrvDomainLxcOpenNamespace)(virDomainPtr dom,
> > +                                    int **fdlist,
> > +                                    unsigned int flags);
> > +
> >  /**
> >   * _virDriver:
> >   *
> > @@ -1107,6 +1112,7 @@ struct _virDriver {
> >      virDrvNodeGetCPUMap                 nodeGetCPUMap;
> >      virDrvDomainFSTrim                  domainFSTrim;
> >      virDrvDomainSendProcessSignal       domainSendProcessSignal;
> > +    virDrvDomainLxcOpenNamespace        domainLxcOpenNamespace;
> 
> No EnterNamespace driver callback?

The 'virDomainLxcEnterNamespace' API is special in that it is rnu
purely client-side, not in the daemon. It is pretty much just a
dumb wrapper around 'setns()' and 'readdir(/proc/self/ns)' to avoid
apps having to know about those low level impl details.

> > +++ b/src/lxc/lxc_driver.c
> > @@ -4544,6 +4544,7 @@ static virDriver lxcDriver = {
> >      .domainShutdown = lxcDomainShutdown, /* 1.0.1 */
> >      .domainShutdownFlags = lxcDomainShutdownFlags, /* 1.0.1 */
> >      .domainReboot = lxcDomainReboot, /* 1.0.1 */
> > +    .domainLxcOpenNamespace = lxcDomainOpenNamespace, /* 1.0.2 */
> 
> Again, no EnterNamespace callback registration?

Same note as above - the driver API isn't used for this code since
it is client side.

> ACK with those issues fixed.  It made it nice that we already have
> libvirt-qemu to copy from.

Indeed, it would have taken me ages to get this right without copying
from libvirt-qemu :-)

Daniel
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