#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
#  Copyright (c) 2018 SWITCH http://www.switch.ch
#
#  Licensed under the Apache License, Version 2.0 (the "License");
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
#  limitations under the License.
#

from __future__ import print_function
import argparse
import os
import subprocess
import sys
import json

__version__ = '1.0.0'

# default ceph values
CEPH_EXEC = '/usr/bin/ceph'
CEPH_COMMAND = 'mgr dump -f json'

CEPH_MGR_DUMP_EXAMPLE = '''
$ ceph --version
ceph version 12.2.7 (3ec878d1e53e1aeb47a9f619c49d9e7c0aa384d5) luminous (stable)
$ ceph mgr dump -f json|jq .
{
  "epoch": 165,
  "active_gid": 248001409,
  "active_name": "zhdk0013",
  "active_addr": "10.10.10.9:6800/810408",
  "available": true,
  "standbys": [
    {
      "gid": 247991934,
      "name": "zhdk0009",
      "available_modules": [
        "balancer",
        "dashboard",
        "influx",
        "localpool",
        "prometheus",
        "restful",
        "selftest",
        "status",
        "zabbix"
      ]
    },
    {
      "gid": 248011196,
      "name": "zhdk0025",
      "available_modules": [
        "balancer",
        "dashboard",
        "influx",
        "localpool",
        "prometheus",
        "restful",
        "selftest",
        "status",
        "zabbix"
      ]
    }
  ],
  "modules": [
    "balancer",
    "restful",
    "status"
  ],
  "available_modules": [
    "balancer",
    "dashboard",
    "influx",
    "localpool",
    "prometheus",
    "restful",
    "selftest",
    "status",
    "zabbix"
  ],
  "services": {}
}
'''

# nagios exit code
STATUS_OK = 0
STATUS_WARNING = 1
STATUS_ERROR = 2
STATUS_UNKNOWN = 3


def main():
    # parse args
    parser = argparse.ArgumentParser(description="'ceph mgr dump' nagios plugin.")
    parser.add_argument('-e', '--exe', help='ceph executable [%s]' % CEPH_EXEC)
    parser.add_argument('-c', '--conf', help='alternative ceph conf file')
    parser.add_argument('-m', '--monaddress', help='ceph monitor to use for queries (address[:port])')
    parser.add_argument('-i', '--id', help='ceph client id')
    parser.add_argument('-n', '--name', help='ceph client name')
    parser.add_argument('-k', '--keyring', help='ceph client keyring file')
    parser.add_argument('-V', '--version', help='show version and exit', action='store_true')
    args = parser.parse_args()

    if args.version:
        print("version {}".format(__version__))
        return STATUS_OK

    # validate args
    ceph_exec = args.exe if args.exe else CEPH_EXEC
    if not os.path.exists(ceph_exec):
        print("MGR ERROR: ceph executable '{}' doesn't exist".format(ceph_exec))
        return STATUS_UNKNOWN

    if args.conf and not os.path.exists(args.conf):
        print("MGR ERROR: ceph conf file '{}' doesn't exist".format(args.conf))
        return STATUS_UNKNOWN

    if args.keyring and not os.path.exists(args.keyring):
        print("MGR ERROR: keyring file '{}' doesn't exist".format(args.keyring))
        return STATUS_UNKNOWN

    # build command
    ceph_cmd = [ceph_exec]
    if args.monaddress:
        ceph_cmd.append('-m')
        ceph_cmd.append(args.monaddress)
    if args.conf:
        ceph_cmd.append('-c')
        ceph_cmd.append(args.conf)
    if args.id:
        ceph_cmd.append('--id')
        ceph_cmd.append(args.id)
    if args.name:
        ceph_cmd.append('--name')
        ceph_cmd.append(args.name)
    if args.keyring:
        ceph_cmd.append('--keyring')
        ceph_cmd.append(args.keyring)
    ceph_cmd.extend(CEPH_COMMAND.split(' '))

    # exec command
    p = subprocess.Popen(ceph_cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    output, err = p.communicate()

    if p.returncode != 0 or not output:
        print("MGR ERROR: {}".format(err))
        return STATUS_UNKNOWN

    # load json output and parse
    mgr_dump = None
    try:
        mgr_dump = json.loads(output)
    except Exception as e:
        print("MGR ERROR: could not parse '{}' output: {}: {}".format(ceph_cmd, output, e))
        return STATUS_UNKNOWN

    # check active
    if 'active_name' not in mgr_dump:
        print("MGR CRITICAL: not active mgr found")
        print("JSON: {}".format(json.dumps(mgr_dump)))
        return STATUS_ERROR

    active_mgr_name = mgr_dump['active_name']
    # check standby
    standby_mgr_names = []
    for standby_mgr in mgr_dump['standbys']:
        standby_mgr_names.append(standby_mgr['name'])

    if len(standby_mgr_names) <= 0:
        print("MGR WARN: active: {} but no standbys".format(active_mgr_name))
        return STATUS_WARNING
    else:
        print("MGR OK: active: {}, standbys: {}".format(active_mgr_name,
                                                        ", ".join(standby_mgr_names)))
        return STATUS_OK

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