[PATCH] virsh: Add QMP command wrapping for 'qemu-monitor-command'
Issuing simple QMP commands is pain as they need to be wrapped by the
JSON wrapper:
{ "execute": "COMMAND" }
and optionally also:
{ "execute": "COMMAND", "arguments":...}
For simple commands without arguments we can add syntax sugar to virsh
which allows simple usage of QMP and additionally prepares also for
passing through of the 'arguments' section:
virsh qemu-monitor-command --qmpwrap $VM query-status
is equivalent to
virsh qemu-monitor-command $VM '{"execute":"query-status"}'
and
virsh qemu-monitor-command --qmpwrap $VM query-named-block-nodes
'{"flat":true}'
is equivalent to
virsh qemu-monitor-command $VM
'{"execute":"query-named-block-nodes",
"arguments":{"flat":true}}'
Signed-off-by: Peter Krempa <pkrempa(a)redhat.com>
---
I originally called the flag '--qmp' but that could be confusing given
that we have '--hmp'. On the other hand it's shorter so I wouldn't mind
turning it back to '--qmp'.
docs/manpages/virsh.rst | 9 ++++++++-
tools/virsh-domain.c | 31 ++++++++++++++++++++++++++++---
2 files changed, 36 insertions(+), 4 deletions(-)
diff --git a/docs/manpages/virsh.rst b/docs/manpages/virsh.rst
index 9561b3f59d..b8cb3cfbc2 100644
--- a/docs/manpages/virsh.rst
+++ b/docs/manpages/virsh.rst
@@ -7694,7 +7694,8 @@ qemu-monitor-command
::
- qemu-monitor-command domain { [--hmp] | [--pretty] [--return-value] } command...
+ qemu-monitor-command domain { [--hmp] | [--qmpwrap] [--pretty]
+ [--return-value] } command...
Send an arbitrary monitor command *command* to domain *domain* through the
QEMU monitor. The results of the command will be printed on stdout.
@@ -7705,6 +7706,12 @@ a space in between before passing the single command to the
monitor.
Note that libvirt uses the QMP to talk to qemu so *command* must be valid JSON
in QMP format to work properly.
+If *--qmpwrap* is passed the first argument passed as *command* is used as a QMP
+command name and appropriately wrapped into a JSON block. Additionally a second
+argument passed as *command* is appended as value of the 'arguments' parameter
+of the QMP command verbatim. *Note* that in the future automatic formatting
+*--qmpwrap* of the arguments might be added, so scripts should format their own JSON.
+
If *--pretty* is given the QMP reply is pretty-printed.
If *--return-value* is given the 'return' key of the QMP response object is
diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c
index e5bd1fdd75..ac57196b20 100644
--- a/tools/virsh-domain.c
+++ b/tools/virsh-domain.c
@@ -9380,6 +9380,10 @@ static const vshCmdOptDef opts_qemu_monitor_command[] = {
.type = VSH_OT_BOOL,
.help = N_("extract the value of the 'return' key from the returned
string")
},
+ {.name = "qmpwrap",
+ .type = VSH_OT_BOOL,
+ .help = N_("wrap the 'cmd' argument in JSON wrapper for QMP")
+ },
{.name = "cmd",
.type = VSH_OT_ARGV,
.flags = VSH_OFLAG_REQ,
@@ -9405,14 +9409,35 @@ cmdQemuMonitorCommand(vshControl *ctl, const vshCmd *cmd)
VSH_EXCLUSIVE_OPTIONS("hmp", "pretty");
VSH_EXCLUSIVE_OPTIONS("hmp", "return-value");
+ VSH_EXCLUSIVE_OPTIONS("hmp", "qmpwrap");
if (!(dom = virshCommandOptDomain(ctl, cmd, NULL)))
return false;
- while ((opt = vshCommandOptArgv(ctl, cmd, opt)))
- virBufferAsprintf(&buf, "%s ", opt->data);
+ if (vshCommandOptBool(cmd, "qmpwrap")) {
+ const char *command = NULL;
+ const char *arguments = NULL;
- virBufferTrim(&buf, " ");
+ if ((opt = vshCommandOptArgv(ctl, cmd, opt)))
+ command = opt->data;
+ if ((opt = vshCommandOptArgv(ctl, cmd, opt)))
+ arguments = opt->data;
+
+ if (!command || (arguments && vshCommandOptArgv(ctl, cmd, opt))) {
+ vshError(ctl, "%s", _("--qmpwrap option requires 1 or 2
arguments"));
+ return false;
+ }
+
+ virBufferAsprintf(&buf, "{\"execute\":\"%s\"",
command);
+ if (arguments)
+ virBufferAsprintf(&buf, ", \"arguments\":%s",
arguments);
+ virBufferAddLit(&buf, "}");
+ } else {
+ while ((opt = vshCommandOptArgv(ctl, cmd, opt)))
+ virBufferAsprintf(&buf, "%s ", opt->data);
+
+ virBufferTrim(&buf, " ");
+ }
monitor_cmd = virBufferContentAndReset(&buf);
--
2.31.1