#!/usr/bin/env python
#
# Plugin to monitor status of Floating IPs in Nova
#
# To monitor instance states, link instance_states to this file.
# E.g.
#    ln -s /usr/share/munin/plugins/nova_instance_states /etc/munin/plugins/
#
# Needs following minimal configuration in plugin-conf.d/nova:
#   [nova_*]
#   user nova
#
# Magic markers
#%# capabilities=autoconf suggest
#%# family=auto

import sys

try:
    from nova import context
    from nova import db
    from nova import flags
    from nova import utils
    from nova.compute import power_state
except ImportError:
    successful_import = False
else:
    successful_import = True


class InstanceState(object):
    instance_counts = None
    states = None

    @classmethod
    def init(cls, metric):
        if cls.states and cls.instance_counts:
            return
        ctxt = context.get_admin_context()
        instances = db.instance_get_all(ctxt)
        cls.instance_counts = {}
        instance_types = {}
        for it in db.instance_type_get_all(ctxt, True):
            instance_types[it['id']] = it['name']

        for instance in instances:
            i = dict(instance)
            i['instance_type'] = i['type'] = instance_types.get(
                                                 instance.instance_type_id,
                                                '(unknown')
            val = cls.instance_counts.get(i[metric], 0)
            cls.instance_counts[i[metric]] = val + 1
        cls.states = cls.instance_counts.keys()

    @classmethod
    def get_states(cls, metric):
        InstanceState.init(metric)
        return cls.states

    @classmethod
    def get_instance_counts(cls, metric):
        InstanceState.init(metric)
        return cls.instance_counts

def get_name(metric, code):
    if metric == "power_state":
        return power_state.name(code)
    elif metric in ["root_gb", "ephemeral_gb"]:
        return "%d gb" % code
    else:
        return code

def print_config(metric):
    states = InstanceState.get_states(metric)
    print 'graph_title Nova Instance %s' % metric
    print 'graph_vlabel instances'
    print 'graph_args --base 1000 --lower-limit 0'
    print 'graph_category nova'
    print 'graph_scale no'
    print 'graph_info This graph shows the number of instances by %s' % metric
    for state in states:
        print '%s.label %s' % (state, get_name(metric, state))
        print '%s.draw LINE2' % state
        print '%s.info %s IPs' % (state, state)


def print_values(metric):
    status = InstanceState.get_instance_counts(metric)
    for (state, value) in status.iteritems():
        print '%s.value %s' % (state, value)

def print_suggest():
    suggest = [ "vm_state",
                "vcpus",
                "task_state",
                "root_gb",
                "ephemeral_gb",
                "power_state",
                "memory_mb",
                "instance_type_id",
                ]
    print "\n".join(suggest)


if __name__ == '__main__':
    argv = sys.argv[:]
    utils.default_flagfile()
    flags.FLAGS(sys.argv)
    metric = argv[0].split('nova_instance_').pop() or 'vm_state'

    if len(argv) > 1:
        if argv[1] == 'config':
            print_config(metric)
        elif argv[1] == 'suggest':
            print_suggest()
        elif argv[1] == 'autoconf':
            if not successful_import:  
                print 'no (failed import nova module)'
                sys.exit(0)
            else:
                print 'yes'
    elif successful_import:
        print_values(metric)
