Re: Issues with the lm_sensors service

On 01/02/2014 10:51 AM, gulikoza wrote:
> hddtemp should be dropped. I don't use it and I wrote the script. My nc did
> not print connection refused so I left it in...

Sounds good.

> HDD temperature could possibly be parsed from smartctl but then again
> selinux might not allow that.

I'll leave that to an interested party...

> One note, please move execution of $pathto_sensors inside the if($kvm == 0)
> so that it is not ran if not needed. Otherwise an error will be added to the
> output (No sensors found - see my mail to this list on 19.8.2013).

Done.

> As an alternative to parsing /proc/cpuinfo, virt-what could be used? But I
> don't know how specific this is to redhat and it would add another
> dependency...

virt-what does essentially the same things although more sophisticated.  Let's
stick with the current mode for now.

> The whole point of detecting kvm is to avoid:
> 
> No sensors found!
> Make sure you loaded all the kernel drivers you need.
> 
> Now, if this is printed on a bare metal machine, it might remind the
> administrator to configure lm_sensors. It is of course useless on a virtual
> machine so that's what I've tried to avoid. Then again, sensors could be run
> with 2> /dev/null, avoid the whole detection procedure and not print any
> errors. But in my case, I wanted to be informed when sensors was not
> configured on a bare metal machine.
> 

Yeah, I think this is useful.

> Regards,
> gulikoza
> 
> -----Original Message-----
> From: Orion Poplawski [mailto:[email protected]] 
> Sent: Thursday, January 02, 2014 6:12 PM
> To: logwatch-devel
> Subject: [Logwatch-devel] Issues with the lm_sensors service
> 
> I have some issues with the zz-lm_sensors service:
> 
> - On Fedora, nc is blocked by SELinux:
> 
>  --------------------- lm_sensors output Begin ------------------------
> 
>  Ncat: Permission denied.
> 
> type=AVC msg=audit(1388681104.665:133): avc:  denied  { name_connect } for
> pid=2394 comm="nc" dest=7634
> scontext=system_u:system_r:logwatch_t:s0-s0:c0.c1023
> tcontext=system_u:object_r:hddtemp_port_t:s0 tclass=tcp_socket
> 
> Even when run from the console I get:
> 
>  --------------------- lm_sensors output Begin ------------------------
> 
>  Ncat: Connection refused.
> 
> 
> This I think is better:
> 
> my $query_hddtemp  = $ENV{'query_hddtemp'}  || '/usr/bin/nc 127.0.0.1 7634
> 2>/dev/null';
> 
> 
> Although I am a little leery of adding network connections to logwatch.
> 
> Also, how common is hddtemp?
> 
> - It always generates output.  I run logwatch in a mode where I only want
> output if there are problems.  So, similar to the zz-disk_space it should
> only
> output if already printing or $Detail is not 0.
> 
> - I *think* SELinux may be blocking access to /proc/cpuinfo as well so that
> it
> cannot determine if a machine is virtual.
> 
> 
> Patch which I'll commit shortly:
> 
>  Index: scripts/services/zz-lm_sensors
> ===================================================================
> --- scripts/services/zz-lm_sensors      (revision 176)
> +++ scripts/services/zz-lm_sensors      (working copy)
> @@ -27,7 +27,7 @@
>  #Output sensors stats
> 
>  my $pathto_sensors = $ENV{'pathto_sensors'} || '/usr/bin/sensors';
> -my $query_hddtemp  = $ENV{'query_hddtemp'}  || '/usr/bin/nc 127.0.0.1
> 7634';
> +my $query_hddtemp  = $ENV{'query_hddtemp'}  || '/usr/bin/nc 127.0.0.1 7634
> 2>/dev/null';
>  my $get_kvm_status = $ENV{'get_kvm_status'} || 'cat /proc/cpuinfo | grep -c
> "QEMU Virtual CPU"';
> 
>  my $sensors = qx($pathto_sensors);
> @@ -34,7 +34,7 @@
>  my $hdd     = qx($query_hddtemp);
>  my $kvm     = qx($get_kvm_status);
> 
> -if ($kvm == 0) {
> +if ($kvm == 0 and (($ENV{PRINTING} eq 'y') or $Detail)) {
>     if ($sensors) {
>        print $sensors;
>     }
> 
> 
> 


-- 
Orion Poplawski
Technical Manager                     303-415-9701 x222
NWRA, Boulder/CoRA Office             FAX: 303-415-9702
3380 Mitchell Lane                       [email protected]
Boulder, CO 80301                   http://www.nwra.com

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