On 01/27/2012 10:22 AM, Peter Krempa wrote:
This patch adds a new command "desc" to show and modify titles and description for the domains using the new API.
Are your plans to have "desc" also modify metadata, or would that be better suited to a new command, probably named "metadata"?
This patch also adds a new flag for the "list" command to show titles in the domain list, to allow easy identification of VMs by storing a short description.
Example: virsh # list --title Id Name State Title ----------------------------------------------- 0 Domain-0 running Mailserver 1 2 fedora paused ---
+/* extract description or title from domain xml */ +static char * +vshGetDomainDescription(vshControl *ctl, virDomainPtr dom, bool title, + unsigned int flags) +{ + char *desc = NULL; + char *domxml = NULL; + virErrorPtr err = NULL; + xmlDocPtr doc = NULL; + xmlXPathContextPtr ctxt = NULL; + int type; + + if (title) + type = VIR_DOMAIN_METADATA_TITLE; + else + type = VIR_DOMAIN_METADATA_DESCRIPTION; + + if ((desc = virDomainGetMetadata(dom, type, NULL, flags))) { + return desc; + } else { + err = virGetLastError(); + + if (err && err->code == VIR_ERR_NO_DOMAIN_METADATA) {
Ah, so we are using the new error (hmm, I should re-read the description - we even documented it that way).
+ desc = vshStrdup(ctl, ""); + virResetLastError(); + return desc; + } + + if (err && err->code != VIR_ERR_NO_SUPPORT) + return desc; + } + + /* fall back to xml */ + /* get domains xml description and extract the title/description */ + if (!(domxml = virDomainGetXMLDesc(dom, flags))) { + vshError(ctl, "%s", _("Failed to retrieve domain XML")); + goto cleanup; + } + doc = virXMLParseStringCtxt(domxml, _("(domain_definition)"), &ctxt); + if (!doc) { + vshError(ctl, "%s", _("Couldn't parse domain XML")); + goto cleanup; + } + if (title) + desc = virXPathString("string(./title[1])", ctxt); + else + desc = virXPathString("string(./description[1])", ctxt); + + if (!desc) + desc = vshStrdup(ctl, "");
Looks like a reasonable use of the API.
Prints the available amount of memory on the machine or within a @@ -426,6 +435,29 @@ Define a domain from an XML <file>. The domain definition is registered but not started. If domain is already running, the changes will take effect on the next boot.
+=item B<desc> [I<--live> | I<--config>] [I<--title>] [I<--edit>] + [I<--new-desc> New description or note message] + +Show or modify description and note for a domain. These values are user +fields that allow to store arbitrary textual data to allow easy identifiaction +of domains. Note is a short (maximum 40 characters) field.
Again, careful with the wording. We may want to s/note/title/ to match the XML, and be careful in describing the differences between them. I think this patch is mostly there; but may have more fallout if we make any more tweaks to the public API or description of it. I'm okay if we save <metadata> manipulation from virsh for another day. -- Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org