Description of problem:

Running 'service carbon-cache start' causes an error/warning message even though it works.

Version-Release number of selected component (if applicable):

python-carbon.noarch 0.9.12-3.el6

How reproducible:

With the carbon-cache service not running, issue the command:

  sudo service carbon-cache start

Steps to Reproduce:
1. install the python-carbon package if not already installed
2. stop the carbon-cache service if already running (sudo service carbon-cache stop)
3. start the carbon-cache service (sudo service carbon-cache start)

Actual results:

Starting carbon-cache: /usr/bin/dirname: extra operand `start.pid'
Try `/usr/bin/dirname --help' for more information.
Starting carbon-cache (instance a)
                                                           [  OK  ]

Expected results:

Starting carbon-cache: Starting carbon-cache (instance a)
                                                           [  OK  ]
Additional info:

Because of the error/warning message, running the service start as part of, for instance, a logrotate cron job causes the job to flag an error and, for instance, send an email to the system administrator each time the logrotate job runs.  This is highly annoying!

Reordering the parameters to the daemon call in the start() function in /etc/init.d/carbon-cache as follows resolves the problem:

start() {
    [ -f $CONFIG ] || exit 6
    [ -x $exec ] || exit 5
    echo -n $"Starting `basename $exec`: "
    daemon "$exec --config=$CONFIG --pidfile=$pidfile --logdir=$LOG_DIR start"
    retval=$?
    echo
    [ $retval -eq 0 ] && touch $lockfile
    return $retval
}

Change the daemon line to put the start parameter first and all is well:

    daemon "$exec start --config=$CONFIG --pidfile=$pidfile --logdir=$LOG_DIR"

This works around a parsing error in /etc/rc.d/init.d/functions (which is sourced by /etc/init.d/carbon-cache), specifically in the __pids_var_run() function called by the daemon() function.  In __pids_var_run() there is this line:

    local base=${1##*/}

which parses the first parameter to attempt to extract the filename.  Unfortunately, the first parameter is not a clean filepath/filename, but has the trailing 'start' appended, which causes the parsing to return a bad result.