Re: [Xen-changelog] Improve error handling, in particular fixing the ProtocolError that is thrown

[Anthony Liguori <aliguori@us.ibm.com>]

Xen patchbot -unstable wrote:
> # HG changeset patch
> # User emellor@leeni.uk.xensource.com
> # Node ID da24df1ea484cf72dc9d367d52e828777e0e20cd
> # Parent  c1bb4eb565296bdb00aed84fcc877befbcebd8e9
> Improve error handling, in particular fixing the ProtocolError that is thrown
> when a domain is specified by the user that does not exist.  Added a few
> error codes -- many more to come, I expect.
>
> Signed-off-by: Ewan Mellor <ewan@xensource.com>
>
> diff -r c1bb4eb56529 -r da24df1ea484 tools/python/xen/xend/server/XMLRPCServer.py
> --- a/tools/python/xen/xend/server/XMLRPCServer.py	Thu Mar 23 10:58:19 2006
> +++ b/tools/python/xen/xend/server/XMLRPCServer.py	Thu Mar 23 11:59:43 2006
> @@ -13,25 +13,45 @@
>  # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
>  #============================================================================
>  # Copyright (C) 2006 Anthony Liguori <aliguori@us.ibm.com>
> -# Copyright (C) 2006 XenSource Ltd
> +# Copyright (C) 2006 XenSource Ltd.
>  #============================================================================
> +
> +import xmlrpclib
>  
>  from xen.xend import XendDomain, XendDomainInfo, XendNode, \
>                       XendLogging, XendDmesg
>  from xen.util.xmlrpclib2 import UnixXMLRPCServer, TCPXMLRPCServer
>  
> -from xen.xend.XendClient import XML_RPC_SOCKET
> +from xen.xend.XendClient import XML_RPC_SOCKET, ERROR_INVALID_DOMAIN
>  
>  def lookup(domid):
> -    return XendDomain.instance().domain_lookup_by_name_or_id(domid)
> +    try:
> +        return XendDomain.instance().domain_lookup_by_name_or_id(domid)
> +    except exn:
> +        log.exception(exn)
> +        raise exn
>  
>  def dispatch(domid, fn, args):
>      info = lookup(domid)
> -    return getattr(info, fn)(*args)
> +    if info:
> +        try:
> +            return getattr(info, fn)(*args)
> +        except exn:
> +            log.exception(exn)
>   

log doesn't appear to be defined in this scope.

Also, there appears to be a problem with the except syntax.  Don't you mean:

except Exception, exn:

Regards,

Anthony Liguori

> +            raise exn
> +    else:
> +        raise xmlrpclib.Fault(ERROR_INVALID_DOMAIN, domid)
>  
>  def domain(domid):
>      info = lookup(domid)
> -    return info.sxpr()
> +    if info:
> +        try:
> +            return info.sxpr()
> +        except exn:
> +            log.exception(exn)
> +            raise exn
> +    else:
> +        raise xmlrpclib.Fault(ERROR_INVALID_DOMAIN, domid)
>  
>  def domains(detail=1):
>      if detail < 1:
> diff -r c1bb4eb56529 -r da24df1ea484 tools/python/xen/xm/main.py
> --- a/tools/python/xen/xm/main.py	Thu Mar 23 10:58:19 2006
> +++ b/tools/python/xen/xm/main.py	Thu Mar 23 11:59:43 2006
> @@ -1,6 +1,6 @@
>  # (C) Copyright IBM Corp. 2005
>  # Copyright (C) 2004 Mike Wray
> -# Copyright (c) 2005 XenSource Ltd
> +# Copyright (c) 2005-2006 XenSource Ltd.
>  #
>  # Authors:
>  #     Sean Dague <sean at dague dot net>
> @@ -38,7 +38,7 @@
>  from xen.xm.opts import *
>  
>  import console
> -
> +import xen.xend.XendClient
>  from xen.xend.XendClient import server
>  
>  # getopt.gnu_getopt is better, but only exists in Python 2.3+.  Use
> @@ -1111,7 +1111,10 @@
>          except SystemExit:
>              sys.exit(1)
>          except xmlrpclib.Fault, ex:
> -            print "Error: %s" % ex.faultString
> +            if ex.faultCode == xen.xend.XendClient.ERROR_INVALID_DOMAIN:
> +                print "Error: the domain '%s' does not exist." % ex.faultString
> +            else:
> +                print "Error: %s" % ex.faultString
>              sys.exit(1)
>          except:
>              print "Unexpected error:", sys.exc_info()[0]
>
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