zpool status block for zabbix/grafana

oss-zpool-status.py

#!/usr/bin/python
'''
Make use of backend's CSS (it's a "bootstrap" deep in its heart).
Note: any inline "style" elements are filtered out!

JFYI:
.p-a-0 { padding:0 }

Usage:
  0. Put this script to, say, /etc/zabbix/oss-status.py
  1. Check /etc/zabbix/zabbix_agentd.conf to make sure you have 
	Include=/etc/zabbix/zabbix_agentd.d/
     line there and uncommented.
  2. Create /etc/zabbix/zabbix_agentd.d/ossNN.conf with the line
	UserParameter= oss.zpool, python /etc/zabbix/oss-status.py
  3. Make zabbix agent sure about your changes.
'''

import subprocess
import re
import sys

MAX_LINES_FOR_1_COLUMN = 4 # make table two-columns if more lines fetched

class goodPopen(subprocess.Popen):
    '''You don't want to .wait() it yourself.'''

    def __enter__(self, *av):
    	'Nothing special, just provide the interface.'
        return self

    def __exit__(self, xt, xv, tb):
    	'Do what you mostly forget to. Let exceptions to go.'
        self.wait()
#end class goodPopen

# make sure zabbix cannot do anything else!
def fetch_status(status_cmd=('sudo', '/usr/sbin/zpool', 'status')):
    'Run status command, grab output, return filtered.'
    values = []
    with goodPopen(status_cmd, stdout = subprocess.PIPE, stderr = subprocess.PIPE) as pipe:
        for line in pipe.stdout.xreadlines():
            if not re.search('ONLINE|OFFLINE|DEGRADED|FAULTED|REMOVED|UNAVAIL', line):
	        continue
	    values.append(tuple(line.split()[:2])) # (<pool>, <status>)
    return values

def render_value(value,
                 success_classes=('text-success',),
		 error_classes=('text-error',)):
    'Returns display string and CSS class(es) for an appropriate entry.'
    pool, status = value
    if status == 'ONLINE':
        klass = ' '.join(success_classes)
        displ = pool
    else:
        klass = ' '.join(error_classes)
        displ = pool + '<br />' + status # display status value, if not "ok"
    return displ, klass


def main():
    values = fetch_status()
    header = values.pop(0) # the 1st line is the header (the whole pool status)

    displ, klass = render_value(('pool state', header[1]),
                                success_classes=('text-success',
				                 'icon-gf', 'icon-gf-online',),
                                error_classes=('alert', 'alert-error',
			                       'icon-gf', 'icon-gf-event-error',))

    colspan = (len(values) > MAX_LINES_FOR_1_COLUMN) and ' colspan=2' or ''

    output_string = '<table class="max-width text-center"><thead>' \
	+ '<tr><th' + colspan + ' class="text-center ' + klass + '">' + displ + '</th></tr>' \
	+ '</thead><tbody>'

    tds = ['<td class="p-a-0 ' + cls + '">' + dsp + '</td>'
           for dsp, cls in map(render_value, values)]

    tr = ''
    for td in tds:
        if colspan:
            # quite simplified: only two columns supported
            if tr:
	        output_string += '<tr class=p-a-0>' + tr + td + '</tr>\n'
	        tr = ''
	    else:
	        tr = td
        else:
	    output_string += '<tr>' + td + '</tr>\n'

    print output_string + "</tbody></table>"
    return 0

if __name__ == '__main__':
    sys.exit(main())
# EOF #