On Thu, Oct 04, 2012 at 05:22:20PM -0600, Eric Blake wrote:

I was using qemu-monitor-command during development, and found it quite hard to use. Compare the results of this patch on ease of reading:

$ virsh qemu-monitor-command dom '{"execute":"query-version"}' {"return":{"qemu":{"micro":1,"minor":12,"major":0},"package":"(qemu-kvm-0.12.1.2)"},"id":"libvirt-7683"}

$ virsh qemu-monitor-command --pretty dom '{"execute":"query-version"}' { "return": { "qemu": { "micro": 1, "minor": 12, "major": 0 }, "package": "(qemu-kvm-0.12.1.2)" }, "id": "libvirt-7674" }

* tools/virsh-host.c (cmdQemuMonitorCommand): New option. * tools/virsh.pod (qemu-monitor-command): Document it. ---

Note that 'qemu-monitor-command dom --pretty --hmp info version' happens to truncate 0.12.1(qemu-kvm-0.12.1.2) into just 0.12 (since that is the portion of the prefix of the string that forms a valid JSON subsequence); we probably have a bug in virJSONValueFromString for not rejecting trailing junk, but that's a matter for another patch; for now, I just documented that --hmp and --pretty don't make sense together in the man page.

I'd tweak the patch to reject the combination of --hmp and --pretty; other than that it looks like a great readability enhancement. Dave

tools/virsh-host.c | 15 +++++++++++++++ tools/virsh.pod | 10 ++++++---- 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/tools/virsh-host.c b/tools/virsh-host.c index 2c46336..40ad8de 100644 --- a/tools/virsh-host.c +++ b/tools/virsh-host.c @@ -38,6 +38,7 @@ #include "virsh-domain.h" #include "xml.h" #include "virtypedparam.h" +#include "json.h"

/* * "capabilities" command @@ -529,6 +530,8 @@ static const vshCmdInfo info_qemu_monitor_command[] = { static const vshCmdOptDef opts_qemu_monitor_command[] = { {"domain", VSH_OT_DATA, VSH_OFLAG_REQ, N_("domain name, id or uuid")}, {"hmp", VSH_OT_BOOL, 0, N_("command is in human monitor protocol")}, + {"pretty", VSH_OT_BOOL, 0, + N_("pretty-print any qemu monitor protocol output")}, {"cmd", VSH_OT_ARGV, VSH_OFLAG_REQ, N_("command")}, {NULL, 0, 0, NULL} }; @@ -544,6 +547,7 @@ cmdQemuMonitorCommand(vshControl *ctl, const vshCmd *cmd) const vshCmdOpt *opt = NULL; virBuffer buf = VIR_BUFFER_INITIALIZER; bool pad = false; + virJSONValuePtr pretty = NULL;

dom = vshCommandOptDomain(ctl, cmd, NULL); if (dom == NULL) @@ -567,6 +571,16 @@ cmdQemuMonitorCommand(vshControl *ctl, const vshCmd *cmd) if (virDomainQemuMonitorCommand(dom, monitor_cmd, &result, flags) < 0) goto cleanup;

+ if (vshCommandOptBool(cmd, "pretty")) { + char *tmp; + pretty = virJSONValueFromString(result); + if (pretty && (tmp = virJSONValueToString(pretty, true))) { + VIR_FREE(result); + result = tmp; + } else { + vshResetLibvirtError(); + } + } vshPrint(ctl, "%s\n", result);

ret = true; @@ -574,6 +588,7 @@ cmdQemuMonitorCommand(vshControl *ctl, const vshCmd *cmd) cleanup: VIR_FREE(result); VIR_FREE(monitor_cmd); + virJSONValueFree(pretty); if (dom) virDomainFree(dom);

diff --git a/tools/virsh.pod b/tools/virsh.pod index c02ffe8..ac8a00f 100644 --- a/tools/virsh.pod +++ b/tools/virsh.pod @@ -2910,15 +2910,17 @@ attaching to an externally launched QEMU process. There may be issues with the guest ABI changing upon migration, and hotunplug may not work.

-=item B<qemu-monitor-command> I<domain> [I<--hmp>] I<command>... +=item B<qemu-monitor-command> I<domain> { [I<--hmp>] | [I<--pretty>] } +I<command>...

Send an arbitrary monitor command I<command> to domain I<domain> through the qemu monitor. The results of the command will be printed on stdout. If I<--hmp> is passed, the command is considered to be a human monitor command and libvirt will automatically convert it into QMP if needed. In that case -the result will also be converted back from QMP. If more than one argument -is provided for I<command>, they are concatenated with a space in between -before passing the single command to the monitor. +the result will also be converted back from QMP. If I<--pretty> is given, +and the monitor uses QMP, then the output will be pretty-printed. If more +than one argument is provided for I<command>, they are concatenated with a +space in between before passing the single command to the monitor.

=back

-- 1.7.11.4

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