[Libvir] [patch 9/9] Implement better error reporting

[Daniel P. Berrange]

On Sat, Feb 17, 2007 at 01:11:48PM +0000, Richard W.M. Jones wrote:
> oneMark McLoughlin wrote:
> >Add a qemudLog() function which uses syslog() if we're in
> >daemon mode, doesn't output INFO/DEBUG messages unless
> >the verbose flag is set and doesn't output DEBUG messages
> >unless compiled with --enable-debug.
> 
> You're all gonna hate this I know, but libvirtd handles syslog by 
> forking an external logger(1) process.  Messages sent to stderr go to 
> syslog.  This is partly necessary because the SunRPC code within glibc 
> is a bit too happy to send debug messages to stderr & nowhere else.

Is this just wrt to the server side of SunRPC, or does it apply to the
client side too ?  If using libvirt from command line tools it won't
be nice if SunRPC is spewing crap to STDERR.

> #ifdef LOGGER
>         /* Send stderr to syslog using logger.  It's a lot simpler
>          * to do this.  Note that SunRPC in glibc prints lots of
>          * gumf to stderr and it'd be a load of work to change that.
>          */
>         int fd[2];
>         if (pipe (fd) == -1) {
>             perror ("pipe");
>             exit (2);
>         }
>         int pid = fork ();
>         if (pid == -1) {
>             perror ("fork");
>             exit (2);
>         }
>         if (pid == 0) {         /* Child - logger. */
>             const char *args[] = {
>                 "logger", "-tlibvirtd", "-p", "daemon.notice", NULL
>             };
>             close (fd[1]);
>             dup2 (fd[0], 0);
>             close (fd[0]);
>             execv (LOGGER, (char *const *) args);
>             perror ("execv");
>             _exit (1);
>         }
>         close (fd[0]);
>         dup2 (fd[1], 2);
>         close (fd[1]);
> #endif

BTW, need to make sure all file descriptors are either explicitly closed,
or have close-on-exec set

Dan.
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