Re: [libvirt] [PATCH 2/4] snapshot: add 'virsh snapshot-info'

Expose the recent API additions in virsh. Borrows ideas from 'dominfo' for the general type of information to display. Output looks like: $ tools/virsh snapshot-info fedora-local tmp Name: tmp Domain: fedora-local Current: no State: disk-snapshot Parent: - Children: 1 Descendants: 2 Metadata: yes possibly with fewer lines when talking to older servers. * tools/virsh.c (cmdSnapshotInfo): New command. * tools/virsh.pod (snapshot-info): Document it. --- tools/virsh.c | 125 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ tools/virsh.pod | 5 ++ 2 files changed, 130 insertions(+), 0 deletions(-) diff --git a/tools/virsh.c b/tools/virsh.c index ffe6ed2..6a85338 100644 --- a/tools/virsh.c +++ b/tools/virsh.c @@ -16601,6 +16601,129 @@ cleanup: } /* + * "snapshot-info" command + */ +static const vshCmdInfo info_snapshot_info[] = { + {"help", N_("snapshot information")}, + {"desc", N_("Returns basic information about a snapshot.")}, + {NULL, NULL} +}; + +static const vshCmdOptDef opts_snapshot_info[] = { + {"domain", VSH_OT_DATA, VSH_OFLAG_REQ, N_("domain name, id or uuid")}, + {"snapshotname", VSH_OT_DATA, 0, N_("snapshot name")}, + {"current", VSH_OT_BOOL, 0, N_("info on current snapshot")}, + {NULL, 0, 0, NULL} +}; + +static bool +cmdSnapshotInfo(vshControl *ctl, const vshCmd *cmd) +{ + virDomainPtr dom; + virDomainSnapshotPtr snapshot = NULL; + const char *name; + char *doc = NULL; + char *tmp; + char *parent = NULL; + bool ret = false; + int count; + unsigned int flags; + int current; + int metadata; + + if (!vshConnectionUsability(ctl, ctl->conn)) + return false; + + dom = vshCommandOptDomain(ctl, cmd, NULL); + if (dom == NULL) + return false; + + if (vshLookupSnapshot(ctl, cmd, "snapshotname", true, dom, +&snapshot,&name)< 0) + goto cleanup; + + vshPrint(ctl, "%-15s %s\n", _("Name:"), name); + vshPrint(ctl, "%-15s %s\n", _("Domain:"), virDomainGetName(dom)); + + /* Determine if snapshot is current; this is useful enough that we + * attempt a fallback. */ + current = virDomainSnapshotIsCurrent(snapshot, 0); + if (current< 0) { + virDomainSnapshotPtr other = virDomainSnapshotCurrent(dom, 0); + + virResetLastError(); + current = 0; + if (other) { + if (STREQ(name, virDomainSnapshotGetName(other))) + current = 1; + virDomainSnapshotFree(other); + } + } + vshPrint(ctl, "%-15s %s\n", _("Current:"), + current> 0 ? _("yes") : _("no")); + + /* Get the XML configuration of the snapshot to determine the + * state of the machine at the time of the snapshot. */ + doc = virDomainSnapshotGetXMLDesc(snapshot, 0); + if (!doc) + goto cleanup; + + tmp = strstr(doc, "<state>"); + if (!tmp) { + vshError(ctl, "%s", + _("unexpected problem reading snapshot xml")); + goto cleanup; + } + tmp += strlen("<state>"); + vshPrint(ctl, "%-15s %.*s\n", _("State:"), + (int) (strchr(tmp, '<') - tmp), tmp); + + if (vshGetSnapshotParent(ctl, snapshot,&parent)< 0) + goto cleanup; + vshPrint(ctl, "%-15s %s\n", _("Parent:"), parent ? parent : "-"); + + /* Children, Descendants. After this point, the fallback to + * compute children is too expensive, so we gracefully quit if the + * APIs don't exist. */ + if (ctl->useSnapshotOld) { + ret = true; + goto cleanup; + } + flags = 0; + count = virDomainSnapshotNumChildren(snapshot, 0); + if (count< 0) + goto cleanup; + vshPrint(ctl, "%-15s %d\n", _("Children:"), count); + flags = VIR_DOMAIN_SNAPSHOT_LIST_DESCENDANTS; + count = virDomainSnapshotNumChildren(snapshot, flags); + if (count< 0) + goto cleanup; + vshPrint(ctl, "%-15s %d\n", _("Descendants:"), count); + + /* Metadata; the fallback here relies on the fact that metadata + * used to have an all-or-nothing effect on snapshot count. */ + metadata = virDomainSnapshotHasMetadata(snapshot, 0); + if (metadata< 0) { + virResetLastError(); + count = virDomainSnapshotNum(dom, + VIR_DOMAIN_SNAPSHOT_LIST_METADATA); + metadata = count != 0; + } + vshPrint(ctl, "%-15s %s\n", _("Metadata:"), + metadata> 0 ? _("yes") : _("no")); + + ret = true; + +cleanup: + VIR_FREE(doc); + VIR_FREE(parent); + if (snapshot) + virDomainSnapshotFree(snapshot); + virDomainFree(dom); + return ret; +} + +/* * "snapshot-list" command */ static const vshCmdInfo info_snapshot_list[] = { @@ -17702,6 +17825,8 @@ static const vshCmdDef snapshotCmds[] = { info_snapshot_dumpxml, 0}, {"snapshot-edit", cmdSnapshotEdit, opts_snapshot_edit, info_snapshot_edit, 0}, + {"snapshot-info", cmdSnapshotInfo, opts_snapshot_info, + info_snapshot_info, 0}, {"snapshot-list", cmdSnapshotList, opts_snapshot_list, info_snapshot_list, 0}, {"snapshot-parent", cmdSnapshotParent, opts_snapshot_parent, diff --git a/tools/virsh.pod b/tools/virsh.pod index ef71717..6553825 100644 --- a/tools/virsh.pod +++ b/tools/virsh.pod @@ -2504,6 +2504,11 @@ a snapshot name must be done with care, since the contents of some snapshots, such as internal snapshots within a single qcow2 file, are accessible only from the original name. +=item B<snapshot-info> I<domain> {I<snapshot> | I<--current>} + +Output basic information about a named<snapshot>, or the current snapshot +with I<--current>. + =item B<snapshot-list> I<domain> [{I<--parent> | I<--roots> | I<--tree>}] [{[I<--from>] B<snapshot> | I<--current>} [I<--descendants>]] [I<--metadata>] [I<--leaves>]