[collectd] [PATCH] Collectd sensors plugin ignores /etc/sensors.d support from lm_sensors-3.1+

[Pavel V.]

Hi, collectd community.

I finally found why my collectd ignores my sensors config.
My problem is like to described at http://collectd.org/bugs/view.php?id=21 first comment.

The collectd does not need to use own hardcoded default config to initialise libsensors when
SENSORS_API_VERSION >= 0x400. The sensors_init() with hardcoded (not NULL) default config breaks
support for read extra configuration files from /etc/sensors.d, introduced in lm_sensors-3.1.
We can use sensors_init(NULL) since API 0x400, as the lm_sensors-3.0.0 manpage describes the
following usage:

 int sensors_init(FILE *input);

 sensors_init() loads the configuration  file.
       If FILE is NULL, the default configuration  files  are  used  (see  the
       FILES section below). Most applications will want to do that.

    FILES section:
       /etc/sensors3.conf
       /etc/sensors.conf
              The  system-wide  libsensors(3)  configuration  file.  /etc/sen-
              sors3.conf is tried first, and if it  doesn't  exist,  /etc/sen-
              sors.conf is used instead.

 So, all default config files will be processed when doing sensors_init(NULL).
 After the lm_sensors-3.1 release, the FILES section additionally has :

       /etc/sensors.d
              A  directory  where you can put additional libsensors configura-
              tion files.  Files found in this directory will be processed  in
              alphabetical  order  after the default configuration file.

 So, /etc/sensors.d directory will be processed too.

------

 The proposed patch fixes the initialization for lm_sensors-3.х and adds a directive
 "SensorsConfigFile". For older lm_sensors the old behaviour remains.

 Also, some improvements was done at error processing:

1)
 If stat() fails, then sensors_config_mtime will be set to zero.
 When stat() succeedes later, plugin will not call sensors_free_features() before new sensors_init().
 The 'features' chain will not be cleaned before adding new features to it,
 so each of  sensors will be queried  many times.  Libsensors's sensors_cleanup() will not be called also.
 Fixed all these.
2) If stat() fails, we need no try to call fopen() at this cycle.

So, the the log is clean now:

Used collectd config has :

<Plugin sensors>
    SensorsConfigFile "/etc/null.conf"
</Plugin>

No /etc/null.conf exists at the start moment.

srv01:~/collectd/src/.libs# collectd -fC /root/tmp/04/collectd.conf
[2011-12-14 21:02:02] sensors plugin: stat (/etc/null.conf) failed: No such file or directory
[2011-12-14 21:02:02] read-function of plugin `sensors' failed. Will suspend it for 20 seconds.
[2011-12-14 21:02:02] Initialization complete, entering read-loop.
[2011-12-14 21:02:22] sensors plugin: stat (/etc/null.conf) failed: No such file or directory
[2011-12-14 21:02:22] read-function of plugin `sensors' failed. Will suspend it for 40 seconds.
...doing touch /etc/null.conf
[2011-12-14 21:03:02] sensors plugin: Reloading config from /etc/null.conf
...doing touch /etc/null.conf again
[2011-12-14 21:04:02] sensors plugin: Reloading config from /etc/null.conf
...doing rm /etc/null.conf
[2011-12-14 21:04:42] read-function of plugin `sensors' failed. Will suspend it for 20 seconds.
[2011-12-14 21:05:02] sensors plugin: stat (/etc/null.conf) failed: No such file or directory
[2011-12-14 21:05:02] read-function of plugin `sensors' failed. Will suspend it for 40 seconds.
[2011-12-14 21:05:42] sensors plugin: stat (/etc/null.conf) failed: No such file or directory
[2011-12-14 21:05:42] read-function of plugin `sensors' failed. Will suspend it for 80 seconds.
^C[2011-12-14 21:06:39] Exiting normally.
[2011-12-14 21:06:39] collectd: Stopping 5 read threads.

The proposed patch is attached.

-- 
Regards,,
 Pavel                          mailto:pavel2000 at ngs.ru
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0005-Collectd-sensors-plugin-ignores-etc-sensors.d-Sensor.patch
Type: application/octet-stream
Size: 4520 bytes
Desc: not available
URL: <http://mailman.verplant.org/pipermail/collectd/attachments/20111214/ba5dd26d/attachment.obj>