[libvirt] [PATCH v4] virsh: add [--domain DOMAIN] option to domxml-to-native DOMAIN COMMAND
John Ferlan
jferlan at redhat.com
Wed Jun 14 14:32:16 UTC 2017
On 06/14/2017 09:47 AM, Martin Kletzander wrote:
> On Wed, Jun 14, 2017 at 08:55:25AM -0400, John Ferlan wrote:
>>
>>
>> On 06/02/2017 11:04 AM, Daniel Liu wrote:
>>> The option allows someone to run domain-to-native on already existing
>>> domain without the need of supplying their XML. It is basically
>>> wrapper around 'virsh dumpxml | virsh domxml-to-native /dev/stdin'.
>>>
>>> Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=835476
>>> Signed-off-by: Daniel Liu <srwx4096 at gmail.com>
>>> ---
>>> tools/virsh-domain.c | 51
>>> ++++++++++++++++++++++++++++++++++++++-------------
>>> tools/virsh.pod | 7 ++++---
>>> 2 files changed, 42 insertions(+), 16 deletions(-)
>>>
>>> diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c
>>> index ccb514ef9..3496359c5 100644
>>> --- a/tools/virsh-domain.c
>>> +++ b/tools/virsh-domain.c
>>> @@ -9848,9 +9848,13 @@ static const vshCmdOptDef
>>> opts_domxmltonative[] = {
>>> .flags = VSH_OFLAG_REQ,
>>> .help = N_("target config data type format")
>>> },
>>> + {.name = "domain",
>>> + .type = VSH_OT_DATA,
>>> + .flags = VSH_OFLAG_REQ_OPT,
>>> + .help = N_("domain name, id or uuid")
>>> + },
>>> {.name = "xml",
>>> .type = VSH_OT_DATA,
>>> - .flags = VSH_OFLAG_REQ,
>>> .help = N_("xml data file to export from")
>>> },
>>> {.name = NULL}
>>> @@ -9859,30 +9863,51 @@ static const vshCmdOptDef
>>> opts_domxmltonative[] = {
>>> static bool
>>> cmdDomXMLToNative(vshControl *ctl, const vshCmd *cmd)
>>> {
>>> - bool ret = true;
>>> + bool ret = false;
>>> const char *format = NULL;
>>> - const char *xmlFile = NULL;
>>> - char *configData;
>>> - char *xmlData;
>>> + const char *xml = NULL;
>>
>> nit: no need to change from xmlFile to xml... The less differences the
>> better ;-)
>>
>
> There was no change, it is an additional variable, the original one is
> below. The number of differences would be the same, I believe.
>
If edit the file and change "xml" to "xmlFile" and change the 3 changed
xml variable references things work... Like I said, nit, IDC if it's
changed or not...
>>> + char *xmlData = NULL;
>>> + char *configData = NULL;
>>
>> nit: no need to change order from original, just add ' = NULL' is fine.
>>
>>> unsigned int flags = 0;
>>> virshControlPtr priv = ctl->privData;
>>> + virDomainPtr dom = NULL;
>>>
>>> if (vshCommandOptStringReq(ctl, cmd, "format", &format) < 0 ||
>>> - vshCommandOptStringReq(ctl, cmd, "xml", &xmlFile) < 0)
>>> + vshCommandOptStringReq(ctl, cmd, "xml", &xml) < 0)
e.g., s/&xml/&xmlFile
>>> return false;
>>>
>>> - if (virFileReadAll(xmlFile, VSH_MAX_XML_FILE, &xmlData) < 0)
>>> - return false;
>>> + VSH_EXCLUSIVE_OPTIONS("domain", "xml");
>>>
>>> - configData = virConnectDomainXMLToNative(priv->conn, format,
>>> xmlData, flags);
>>> - if (configData != NULL) {
>>> - vshPrint(ctl, "%s", configData);
>>> - VIR_FREE(configData);
>>> + if (vshCommandOptBool(cmd, "domain") &&
>>> + (!(dom = virshCommandOptDomain(ctl, cmd, NULL))))
>>> + return false;
>>> +
>>> + if (dom) {
>>> + xmlData = virDomainGetXMLDesc(dom, flags);
>>> + } else if (xml) {
e.g.:
else if (xmlFile) {
if (virFileReadAll(xmlFile,...)
>>> + if (virFileReadAll(xml, VSH_MAX_XML_FILE, &xmlData) < 0)
>>> + goto cleanup;
>>> } else {
>>> - ret = false;
>>> + vshError(ctl, "%s", _("need either domain or domain XML"));
>>> + goto cleanup;
>>> + }
>>> +
>>> + if (!xmlData) {
>>> + vshError(ctl, "%s", _("failed to retrieve XML"));
>>> + goto cleanup;
>>> }
>>>
>>> + if (!(configData = virConnectDomainXMLToNative(priv->conn,
>>> format, xmlData, flags))) {
>>> + goto cleanup;
>>> + } else {
>>> + vshPrint(ctl, "%s", configData);
>>> + ret = true;
>>> + }
>>> +
>>> + cleanup:
>>> + virshDomainFree(dom);
>>> VIR_FREE(xmlData);
>>> + VIR_FREE(configData);
>>> return ret;
>>> }
>>>
>>> diff --git a/tools/virsh.pod b/tools/virsh.pod
>>> index aee964689..049c2f3c7 100644
>>> --- a/tools/virsh.pod
>>> +++ b/tools/virsh.pod
>>> @@ -1433,10 +1433,11 @@ the I<format> argument must be B<qemu-argv>.
>>> For Xen hypervisor, the
>>> I<format> argument may be B<xen-xm>, B<xen-xl>, or B<xen-sxpr>. For
>>> LXC hypervisor, the I<format> argument must be B<lxc-tools>.
>>>
>>> -=item B<domxml-to-native> I<format> I<xml>
>>> +=item B<domxml-to-native> I<format>
>>> +{ I<--domain> I<domain-name-or-id-or-uuid> | [I<--xml>] I<xml> }
>>
>> This looks really odd, I think this should be
>>
>> { [I<xml> | [I<--domain> I<domain-name-or-id-uuid>] }
>>
>
> Actually, the only thing that Dan can change is the order, but the rest
> should remain. His version shows that you must supply either --domain
> domain-name-or-id-or-uuid or --xml xml and that in the second case, the
> --xml is optional.
>
> Your suggested solution, however, mean that you must supply either the
> xml (no mention about the optional --xml) or --domain
> domain-name-or-id-or-uuid or nothing (in a really weird way), as the
> latter option is in square brackets.
>
> So the only way this could look differently is:
>
> { [I<--xml>] I<xml> | I<--domain> I<domain-name-or-id-or-uuid> }
>
That's fine - I considered this too, but the [I<--xml>] looked strange,
but I see it's technically correct since having the --xml doesn't
necessarily matter and thus enclosed in brackets.
John
>> I believe that's the way to describe mutually exclusive options where
>> one would be required; otherwise, we have the funky [[ ... ]] which
>> indicates mutually exclusive optional arguments. Search on "{ [" in
>> virsh.pod for some examples. This seems to be the first case where a
>> previously required positional argument can be both a positional and
>> optional as long as the alternative means of describing is provided.
>>
>> Keeping the I<xml> first at least indicates that it can be used
>> *without* the --xml, but is also the "default" when used positionally on
>> the command line. If not used positionally, then the --xml would be
>> required, e.g. if someone used "virsh domxml-to-native --xml @file
>> --format @format".
>>
>> Having the [--domain] indicates that in order to use it, it must have
>> that --domain argument because "virsh domxml-to-native qemu-argv
>> $domainname" would be invalid since the unqualified 2nd argument is
>> expected to be an <xml> file.
>>
>> Whether any of this is written down anywhere - I'm not sure - it's what
>> I've surmised over the few years.
>>
>>
>>>
>>> -Convert the file I<xml> in domain XML format to the native guest
>>> -configuration format named by I<format>. For QEMU/KVM hypervisor,
>>> +Convert the file I<xml> in domain XML format or existing domain to the
>>> +native guest configuration format named by I<format>. For QEMU/KVM
>>> hypervisor,
>>> the I<format> argument must be B<qemu-argv>. For Xen hypervisor, the
>>> I<format> argument may be B<xen-xm>, B<xen-xl>, or B<xen-sxpr>. For
>>> LXC hypervisor, the I<format> argument must be B<lxc-tools>.
>>>
>>
>> Convert the file I<xml> into domain XML format or convert an existing
>> I<--domain> to the native guest configuration format named by I<format>.
>> The I<xml> and I<--domain> arguments are mutually exclusive.
>>
>
> Yes, this sounds better, there is a slight flaw in the original hunk and
> this explains it more nicely.
>
>> John
>>
>> --
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