[Libvirt-cim] [PATCH] Redirect stdout & stderr when run as out-of-process provider

[Chip Vincent]

On 09/22/2011 07:43 PM, Chip Vincent wrote:
>
>
> On 09/22/2011 03:05 PM, Eduardo Lima (Etrunko) wrote:
>> On 09/20/2011 07:33 PM, Chip Vincent wrote:
>>> # HG changeset patch
>>> # User Chip Vincent<cvincent at us.ibm.com>
>>> # Date 1316557881 14400
>>> # Node ID 4d95f2e9f2d8eac1565307def96bd158f5dcf160
>>> # Parent db809376d763493849c2a19f587969eaec619b75
>>> Redirect stdout& stderr when run as out-of-process provider
>>>
>>> When a provider is loaded in-process by Pegasus, messages sent to
>>> stdout and stderr are suppressed. However, when loaded out-of-process,
>>> those same messages appear on the console. This happens excessively when
>>> libvirt-cim LXC_ and XEN_ classes are enumerated and libvirt sends
>>> "libvir: error : no connection driver available for..." messages to
>>> stderr.
>>> In development, this can sometimes prevent console usage. Until a fix is
>>> made to Pegasus, we'll suppress console output during provider
>>> initialization
>>> when run in out-of-process mode.
>>>
>>> Signed-off-by: Chip Vincent<cvincent at us.ibm.com>
>>>
>>> diff --git a/libxkutil/misc_util.c b/libxkutil/misc_util.c
>>> --- a/libxkutil/misc_util.c
>>> +++ b/libxkutil/misc_util.c
>>> @@ -29,6 +29,7 @@
>>> #include<stdarg.h>
>>> #include<unistd.h>
>>> #include<pthread.h>
>>> +#include<errno.h>
>>
>> Why are you including errno.h? Is it because of freopen(), stdout and
>> stderr? I guess you should be including stdio.h if that is the case.
>
> Without including anything new, I got a compilation error. I don't
> recall the details, but a quick google of the error pointed to errno.h.
> However, everything I search now points to stdio.h. I'll fix.

I recall now. errno.h is for the ‘program_invocation_short_name’ varible.

http://www.gnu.org/software/hello/manual/gnulib/Glibc-errno_002eh.html#Glibc-errno_002eh

>
>>
>> Best regards, Etrunko.
>>
>>> #include<libvirt/libvirt.h>
>>> #include<libvirt/virterror.h>
>>>
>>> @@ -540,6 +541,17 @@
>>> {
>>> int ret = 0;
>>>
>>> + /* The tog-pegasus out-of-process provider feature does not
>>> + * redirect stdout and stderr, so it's done here to prevent
>>> + * any messages from taking over the console. One example is
>>> + * verbose connection failures sent to stdout by libvirt. */
>>> + if (strstr(program_invocation_short_name, "cimprovagt") != NULL) {
>>> + CU_DEBUG("Redirecting stdout and stderr");
>>> +
>>> + stdout = freopen("/dev/null", "a", stdout);
>>> + stderr = freopen("/dev/null", "a", stderr);
>>> + }
>>> +
>>> /* double-check lock pattern used for performance reasons */
>>> if (libvirt_initialized == 0) {
>>> pthread_mutex_lock(&libvirt_mutex);
>>>
>>> _______________________________________________
>>> Libvirt-cim mailing list
>>> Libvirt-cim at redhat.com
>>> https://www.redhat.com/mailman/listinfo/libvirt-cim
>>
>>
>

-- 
Chip Vincent
Open Virtualization
IBM Linux Technology Center
cvincent at linux.vnet.ibm.com