#!/usr/bin/env python

# This is a munin plugin to track the amount of disk space each node's
# StorageServer is consuming on behalf of other nodes. This is where the
# shares are kept. If there are N nodes present in the mesh, the total space
# consumed by the entire mesh will be about N times the space reported by
# this plugin.

# Copy this plugin into /etc/munun/plugins/tahoe_storagespace and then put
# the following in your /etc/munin/plugin-conf.d/foo file to let it know
# where to find the basedirectory for each node:
#
#  [tahoe_storagespace]
#  env.basedir_NODE1 /path/to/node1
#  env.basedir_NODE2 /path/to/node2
#  env.basedir_NODE3 /path/to/node3
#
# Allmydata-tahoe must be installed on the system where this plugin is used,
# since it imports a utility module from allmydata.utils .

import os, sys
import commands

nodedirs = []
for k,v in os.environ.items():
    if k.startswith("basedir_"):
        nodename = k[len("basedir_"):]
        nodedirs.append( (nodename, v) )
nodedirs.sort()

seriesname = "storage"

configinfo = \
"""graph_title Allmydata Tahoe Shareholder Space
graph_vlabel bytes
graph_category tahoe
graph_info This graph shows the space consumed by this node's StorageServer
"""

for nodename, basedir in nodedirs:
    configinfo += "%s.label %s\n" % (nodename, nodename)
    configinfo += "%s.draw LINE2\n" % (nodename,)


if len(sys.argv) > 1:
    if sys.argv[1] == "config":
        print configinfo.rstrip()
        sys.exit(0)

for nodename, basedir in nodedirs:
    cmd = "du --bytes --summarize %s" % os.path.join(basedir, "storage")
    rc,out = commands.getstatusoutput(cmd)
    if rc != 0:
        sys.exit(rc)
    bytes, extra = out.split()
    usage = int(bytes)
    print "%s.value %d" % (nodename, usage)