snapshot: add virsh domblklist command

This adds a convenience function to virsh that parses out block
information from the domain xml, making it much easier to see
what strings can be used in all other contexts that demand a
specific block name, especially when given the previous patch
that allows using either target or unique source name.

As an example on a domain with one disk and an empty cdrom drive:

Target     Source
-------------------------------------------
vda        /var/lib/libvirt/images/fedora_12.img
hdc        -

* tools/virsh.c (cmdDomblklist): New function.
* tools/virsh.pod (domblklist): Document it.
This commit is contained in:
Eric Blake 2011-08-20 07:04:24 -06:00
parent 89b6284fd9
commit 88a993b129
2 changed files with 95 additions and 2 deletions

View File

@ -1276,6 +1276,86 @@ cmdDomblkinfo(vshControl *ctl, const vshCmd *cmd)
return ret;
}
/*
* "domblklist" command
*/
static const vshCmdInfo info_domblklist[] = {
{"help", N_("list all domain blocks")},
{"desc", N_("Get the names of block devices for a domain.")},
{NULL, NULL}
};
static const vshCmdOptDef opts_domblklist[] = {
{"domain", VSH_OT_DATA, VSH_OFLAG_REQ, N_("domain name, id or uuid")},
{"inactive", VSH_OT_BOOL, 0,
N_("get inactive rather than running configuration")},
{NULL, 0, 0, NULL}
};
static bool
cmdDomblklist(vshControl *ctl, const vshCmd *cmd)
{
virDomainPtr dom;
bool ret = false;
unsigned int flags = 0;
char *xml = NULL;
xmlDocPtr xmldoc = NULL;
xmlXPathContextPtr ctxt = NULL;
int ndisks;
xmlNodePtr *disks = NULL;
int i;
if (vshCommandOptBool(cmd, "inactive"))
flags |= VIR_DOMAIN_XML_INACTIVE;
if (!vshConnectionUsability(ctl, ctl->conn))
return false;
if (!(dom = vshCommandOptDomain(ctl, cmd, NULL)))
return false;
xml = virDomainGetXMLDesc(dom, flags);
if (!xml)
goto cleanup;
xmldoc = virXMLParseStringCtxt(xml, "domain.xml", &ctxt);
if (!xmldoc)
goto cleanup;
ndisks = virXPathNodeSet("./devices/disk", ctxt, &disks);
if (ndisks < 0)
goto cleanup;
vshPrint(ctl, "%-10s %s\n", _("Target"), _("Source"));
vshPrint(ctl, "------------------------------------------------\n");
for (i = 0; i < ndisks; i++) {
char *target;
char *source;
ctxt->node = disks[i];
target = virXPathString("string(./target/@dev)", ctxt);
if (!target) {
vshError(ctl, "unable to query block list");
goto cleanup;
}
source = virXPathString("string(./source/@file"
"|./source/@dev"
"|./source/@dir"
"|./source/@name)", ctxt);
vshPrint(ctl, "%-10s %s\n", target, source ? source : "-");
VIR_FREE(target);
VIR_FREE(source);
}
ret = 0;
cleanup:
VIR_FREE(disks);
virDomainFree(dom);
return ret;
}
/*
* "suspend" command
*/
@ -13064,6 +13144,7 @@ static const vshCmdDef domManagementCmds[] = {
static const vshCmdDef domMonitoringCmds[] = {
{"domblkinfo", cmdDomblkinfo, opts_domblkinfo, info_domblkinfo, 0},
{"domblklist", cmdDomblklist, opts_domblklist, info_domblklist, 0},
{"domblkstat", cmdDomblkstat, opts_domblkstat, info_domblkstat, 0},
{"domcontrol", cmdDomControl, opts_domcontrol, info_domcontrol, 0},
{"domifstat", cmdDomIfstat, opts_domifstat, info_domifstat, 0},

View File

@ -505,7 +505,8 @@ snapshot metadata with B<snapshot-create>.
Get device block stats for a running domain. A I<block-device> corresponds
to a unique target name (<target dev='name'/>) or source file (<source
file='name'/>) for one of the disk devices attached to I<domain>.
file='name'/>) for one of the disk devices attached to I<domain> (see
also B<domblklist> for listing these names).
=item B<domifstat> I<domain> I<interface-device>
@ -519,7 +520,18 @@ Get memory stats for a running domain.
Get block device size info for a domain. A I<block-device> corresponds
to a unique target name (<target dev='name'/>) or source file (<source
file='name'/>) for one of the disk devices attached to I<domain>.
file='name'/>) for one of the disk devices attached to I<domain> (see
also B<domblklist> for listing these names).
=item B<domblklist> I<domain> [I<--inactive>]
Print a table showing the names of all block devices associated with
I<domain>, as well as the path to the source of each device. If
I<--inactive> is specified, query the block devices that will be used
on the next boot, rather than those currently in use by a running
domain. Other contexts that require a block device name (such as
I<domblkinfo> or I<snapshot-create> for disk snapshots) will accept
either target or unique source names printed by this command.
=item B<blockpull> I<domain> I<path> [I<bandwidth>]