[libvirt] [sandbox PATCH v2 11/19] Image: Add run function

[Daniel P. Berrange]

On Mon, Aug 10, 2015 at 05:16:19PM +0100, Daniel P. Berrange wrote:
> On Tue, Aug 04, 2015 at 08:11:17PM +0000, Eren Yagdiran wrote:
> > Run an already-built template
> > If there is no execution command specified by user, source.get_command will
> > find the command to invoke
> > ---
> >  virt-sandbox-image/virt-sandbox-image.py | 24 ++++++++++++++++++++++++
> >  1 file changed, 24 insertions(+)
> > 
> > diff --git a/virt-sandbox-image/virt-sandbox-image.py b/virt-sandbox-image/virt-sandbox-image.py
> > index 4c19fa8..e20ce22 100755
> > --- a/virt-sandbox-image/virt-sandbox-image.py
> > +++ b/virt-sandbox-image/virt-sandbox-image.py
> > @@ -101,6 +101,30 @@ def check_connect(connectstr):
> >              raise ValueError("%s is not supported by Virt-sandbox" %connectstr)
> >          return True
> >  
> > +def run(args):
> > +    try:
> > +        if args.connect is not None:
> > +            check_connect(args.connect)
> > +        source = dynamic_source_loader(args.source)
> > +        diskfile,configfile = source.get_disk(name=args.name,path=args.imagepath)
> > +
> > +        format = "qcow2"
> > +        commandToRun = args.igniter
> > +        if commandToRun is None:
> > +            commandToRun = source.get_command(configfile)
> > +        cmd = ['virt-sandbox']
> > +        if args.connect is not None:
> > +            cmd.append("-c")
> > +            cmd.append(args.connect)
> > +        params = ['-m','host-image:/=%s,format=%s' %(diskfile,format),
> > +               '--',
> > +               commandToRun]
> > +        cmd = cmd + params
> > +        subprocess.call(cmd)
> > +
> > +    except Exception,e:
> > +        print "Run Error %s" % str(e)
> 
> This code actually ends up launching a sandbox using the template file as
> the root disk image. This is not good, because we need to be able to run
> multiple instances of the sandbox, all using the same template file. As
> such we need to be able to create a new temporary disk image for each
> sandbox instance, that is an overlay on the main template, an then
> delete this temporary disk at shutdown.

Or if we make sure / is read-only that would avoid the problem I
mention here. With normal docker toolchain is / read-only by
default, or do they make it writable with a throw-away snapshot ?

Regards,
Daniel
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