[Kimchi-devel] [PATCH] [Kimchi] Handle URLError exception when creating Template.

[Paulo Ricardo Paz Vital]

On Jun 20 12:48PM, Aline Manera wrote:
>
>
> On 06/14/2016 07:26 PM, pvital at linux.vnet.ibm.com wrote:
> > From: Paulo Vital <pvital at linux.vnet.ibm.com>
> >
> > urllib2 raised URLError when could not access a remote file due to unauthorized
> > access, for example. This patch gives to VMTemplate the ability of handle this
> > exception and raises a relevant error message to user.
> >
> > This patch fixes Issue #959
> >
> > Signed-off-by: Paulo Vital <pvital at linux.vnet.ibm.com>
> > ---
> >   i18n.py       | 1 +
> >   vmtemplate.py | 3 +++
> >   2 files changed, 4 insertions(+)
> >
> > diff --git a/i18n.py b/i18n.py
> > index 2d8390f..b33c6ec 100644
> > --- a/i18n.py
> > +++ b/i18n.py
> > @@ -52,6 +52,7 @@ messages = {
> >                        "to file access control lists for '%(user)s' user if possible, or add the "
> >                        "'%(user)s' to the ISO path group, or (not recommended) 'chmod -R o+x 'path_to_iso'."
> >                        "Details: %(err)s" ),
> > +    "KCHISO0009E": _("Unable to access remote ISO. Details: %(err)s"),
> >
> >       "KCHIMG0001E": _("An error occurred when probing image OS information."),
> >       "KCHIMG0003E": _("Unable to read image file %(filename)s"),
> > diff --git a/vmtemplate.py b/vmtemplate.py
> > index ef92914..6faf4c5 100644
> > --- a/vmtemplate.py
> > +++ b/vmtemplate.py
> > @@ -24,6 +24,7 @@ import urlparse
> >   import uuid
> >   from lxml import etree
> >   from lxml.builder import E
> > +from urllib2 import URLError
> >
> >   from wok.exception import InvalidParameter, ImageFormatError, IsoFormatError
> >   from wok.exception import MissingParameter, OperationFailed
> > @@ -172,6 +173,8 @@ class VMTemplate(object):
> >               return iso_img.probe()
> >           except IsoFormatError:
>
> >               raise InvalidParameter("KCHISO0001E", {'filename': iso})
> > +        except URLError as e:
> > +            raise OperationFailed("KCHISO0009E", {'err': e})
>
> The IsoImage() should raise a IsoFormatError. We need to check why it is not
> being done.
> Is there proper error handlers there?
>

No. If I trace from where the exception is coming, the results is:

IsoImage()->__init__()->_scan()->_get_iso_data() line 422

and none of these methods are handling exceptions, specially the exceptions or
errors from urllib2 module.

I can add a try/exception block in _get_iso_data() and raise something, but IMO
IsoFormatError is not the correct name for this error - the problem is not
related to an ISO format, but not able to access the remote link. Because of
this difference on the kind of error raised, I coded on vmtemplate.

> >       def _get_cdrom_xml(self, libvirt_stream_protocols):
> >           if 'cdrom' not in self.info:
> > --
> > 2.5.5
>

--
Paulo Ricardo Paz Vital
Linux Technology Center, IBM Systems
http://www.ibm.com/linux/ltc/