#!/usr/bin/python
# -*- encoding: utf-8; py-indent-offset: 4 -*-
# +------------------------------------------------------------------+
# |             ____ _               _        __  __ _  __           |
# |            / ___| |__   ___  ___| | __   |  \/  | |/ /           |
# |           | |   | '_ \ / _ \/ __| |/ /   | |\/| | ' /            |
# |           | |___| | | |  __/ (__|   <    | |  | | . \            |
# |            \____|_| |_|\___|\___|_|\_\___|_|  |_|_|\_\           |
# |                                                                  |
# | Copyright Mathias Kettner 2014             mk@mathias-kettner.de |
# +------------------------------------------------------------------+
#
# This file is part of Check_MK.
# The official homepage is at http://mathias-kettner.de/check_mk.
#
# check_mk is free software;  you can redistribute it and/or modify it
# under the  terms of the  GNU General Public License  as published by
# the Free Software Foundation in version 2.  check_mk is  distributed
# in the hope that it will be useful, but WITHOUT ANY WARRANTY;  with-
# out even the implied warranty of  MERCHANTABILITY  or  FITNESS FOR A
# PARTICULAR PURPOSE. See the  GNU General Public License for more de-
# tails. You should have  received  a copy of the  GNU  General Public
# License along with GNU Make; see the file  COPYING.  If  not,  write
# to the Free Software Foundation, Inc., 51 Franklin St,  Fifth Floor,
# Boston, MA 02110-1301 USA.

import urllib2, sys, os, socket, pprint, base64

try:
    from simplejson import json
except ImportError:
    try:
        import json
    except ImportError:
        sys.stdout.write("<<<jolokia_info>>>\n")
        sys.stdout.write("Error: Missing JSON library for Agent Plugin mk_jolokia\n")
        exit()

opt_verbose = '--verbose' in sys.argv
opt_debug   = '--debug' in sys.argv

class PreemptiveBasicAuthHandler(urllib2.HTTPBasicAuthHandler):
    """
    sends basic authentication with the first request,
    before the server even asks for it
    """

    def http_request(self, req):
        url = req.get_full_url()
        realm = None
        user, pw = self.passwd.find_user_password(realm, url)
        if pw:
            raw = "%s:%s" % (user, pw)
            auth = 'Basic %s' % base64.b64encode(raw).strip()
            req.add_unredirected_header(self.auth_header, auth)
        return req

    https_request = http_request


def fetch_var(protocol, server, port, path, suburi, itemspec):
    url = "%s://%s:%d/%s/%s" % (protocol, server, port, suburi, path)
    if opt_verbose:
        sys.stderr.write("DEBUG: Fetching: %s\n" % url)
    try:
        json_data = urllib2.urlopen(url).read()
        if opt_verbose:
            sys.stderr.write("DEBUG: Result: %s\n\n" % json_data)
    except Exception, e:
        if opt_debug:
            raise
        sys.stderr.write("ERROR: %s\n" % e)
        return []


    try:
        obj = json.loads(json_data)
    except Exception, e:
        sys.stderr.write('ERROR: Invalid json code (%s)\n' % e)
        sys.stderr.write('       Response %s\n' % json_data)
        return []

    if obj.get('status', 200) != 200:
        sys.stderr.write('ERROR: Invalid response when fetching url %s\n' % url)
        sys.stderr.write('       Response: %s\n' % json_data)
        return []

    # Only take the value of the object. If the value is an object
    # take the first items first value.
    # {'Catalina:host=localhost,path=\\/test,type=Manager': {'activeSessions': 0}}
    if 'value' not in obj:
        if opt_verbose:
            sys.stderr.write("ERROR: not found: %s\n" % path)
        return []
    val = obj.get('value', None)
    return make_item_list((), val, itemspec)

# convert single values into lists of items in
# case value is a 1-levelled or 2-levelled dict
def make_item_list(path, value, itemspec):
    if type(value) != dict:
        if type(value) == str:
            value = value.replace(r'\/', '/')
        return [(path, value)]
    else:
        result = []
        for key, subvalue in value.items():
            # Handle filtering via itemspec
            miss = False
            while itemspec and '=' in itemspec[0]:
                if itemspec[0] not in key:
                    miss = True
                    break
                itemspec = itemspec[1:]
            if miss:
                continue
            item = extract_item(key, itemspec)
            if not item:
                item = (key,)
            result += make_item_list(path + item, subvalue, [])
        return result

# Example:
# key = 'Catalina:host=localhost,path=\\/,type=Manager'
# itemsepc = [ "path" ]
# --> "/"

def extract_item(key, itemspec):
    path = key.split(":", 1)[-1]
    components = path.split(",")
    item = ()
    comp_dict = {}
    for comp in components:
        parts = comp.split("=")
        if len(parts) == 2:
            left, right = parts
            comp_dict[left] = right
    for pathkey in itemspec:
        if pathkey in comp_dict:
            right = comp_dict[pathkey]
            right = right.replace(r'\/', '/')
            if '/' in right:
                right = '/' + right.split('/')[-1]
            item = item + (right,)
    return item


def query_instance(inst):
    # Prepare user/password authentication via HTTP Auth
    if inst.get("password"):
        password_mngr = urllib2.HTTPPasswordMgrWithDefaultRealm()
        password_mngr.add_password(None, "%s://%s:%d/" %
                (inst["protocol"], inst["server"], inst["port"]), inst["user"], inst["password"])

        if inst["mode"] == 'digest':
            authhandler = urllib2.HTTPDigestAuthHandler(password_mngr)
        elif inst["mode"] == "basic_preemptive":
            authhandler = PreemptiveBasicAuthHandler(password_mngr)
        elif inst["mode"] == "basic" and inst["protocol"] != "https":
            authhandler = urllib2.HTTPBasicAuthHandler(password_mngr)

        opener = urllib2.build_opener(authhandler)
        urllib2.install_opener(opener)

    # Determine type of server
    server_info = fetch_var(inst["protocol"], inst["server"], inst["port"], "", inst["suburi"], "")

    sys.stdout.write('<<<jolokia_info>>>\n')
    if server_info:
        d = dict(server_info)
        version = d.get(('info', 'version'), "unknown")
        product = d.get(('info', 'product'), "unknown")
        if inst.get("product"):
            product = inst["product"]
        agentversion = d.get(('agent',), "unknown")
        sys.stdout.write("%s %s %s %s\n" % (inst["instance"], product, version, agentversion))
    else:
        sys.stdout.write("%s ERROR\n" % (inst["instance"],))
        sys.stdout.write('<<<jolokia_metrics>>>\n')
        sys.stdout.write("%s ERROR\n" % (inst["instance"],))
        return

    sys.stdout.write('<<<jolokia_metrics>>>\n')
    # Fetch the general information first
    for path, title, itemspec in global_vars + specific_vars.get(product, []):
        try:
            values = fetch_var(inst["protocol"], inst["server"], inst["port"], "read/" + path, inst["suburi"], itemspec)

        # In case of network errors skip this server
        except IOError:
            return
        except socket.timeout:
            return
        except:
            if opt_debug:
                raise
            # Simply ignore exceptions. Need to be removed for debugging
            continue

        for subinstance, value in values:
            if not subinstance and not title:
                print "INTERNAL ERROR: %s" % value
                continue

            if "threadStatus" in subinstance or "threadParam" in subinstance:
                continue

            if len(subinstance) > 1:
                item = ",".join((inst["instance"],) + subinstance[:-1])
            else:
                item = inst["instance"]
            if title:
                if subinstance:
                    tit = title + "." + subinstance[-1]
                else:
                    tit = title
            else:
                tit = subinstance[-1]

            sys.stdout.write("%s %s %s\n" % (item.replace(" ", "_"), tit, value))


# Default configuration for all instances
protocol = "http"
server   = "localhost"
port     = 8080
user     = "monitoring"
password = None
mode     = "digest"
suburi   = "jolokia"
instance = None
product  = None

global_vars = [
  ( "java.lang:type=Memory/NonHeapMemoryUsage/used",              "NonHeapMemoryUsage",      [] ),
  ( "java.lang:type=Memory/NonHeapMemoryUsage/max",               "NonHeapMemoryMax",        [] ),
  ( "java.lang:type=Memory/HeapMemoryUsage/used",                 "HeapMemoryUsage",         [] ),
  ( "java.lang:type=Memory/HeapMemoryUsage/max",                  "HeapMemoryMax",           [] ),
  ( "java.lang:type=Threading/ThreadCount",                       "ThreadCount",             [] ),
  ( "java.lang:type=Threading/DaemonThreadCount",                 "DeamonThreadCount",       [] ),
  ( "java.lang:type=Threading/PeakThreadCount",                   "PeakThreadCount",         [] ),
  ( "java.lang:type=Threading/TotalStartedThreadCount",           "TotalStartedThreadCount", [] ),
  ( "java.lang:type=Runtime/Uptime",                              "Uptime",                  [] ),
  ( "java.lang:type=GarbageCollector,name=*/CollectionCount",     "",                        [] ),
  ( "java.lang:type=GarbageCollector,name=*/CollectionTime",      "",                        [] ),
  ( "java.lang:name=CMS%20Perm%20Gen,type=MemoryPool/Usage/used", "PermGenUsage",            [] ),
  ( "java.lang:name=CMS%20Perm%20Gen,type=MemoryPool/Usage/max",  "PermGenMax",              [] ),
]


specific_vars = {
  "weblogic" : [
      ( "*:*/CompletedRequestCount",                                None, [ "ServerRuntime" ] ),
      ( "*:*/QueueLength",                                          None, [ "ServerRuntime" ] ),
      ( "*:*/StandbyThreadCount",                                   None, [ "ServerRuntime" ] ),
      ( "*:*/PendingUserRequestCount",                              None, [ "ServerRuntime" ] ),
      ( "*:Name=ThreadPoolRuntime,*/ExecuteThreadTotalCount",       None, [ "ServerRuntime" ] ),
      ( "*:*/ExecuteThreadIdleCount",                               None, [ "ServerRuntime" ] ),
      ( "*:*/HoggingThreadCount",                                   None, [ "ServerRuntime" ] ),
      ( "*:Type=WebAppComponentRuntime,*/OpenSessionsCurrentCount", None, [ "ServerRuntime", "ApplicationRuntime" ] ),
  ],
  "tomcat" : [
      ( "*:type=Manager,*/activeSessions,maxActiveSessions",        None, [ "path", "context" ] ),
      ( "*:j2eeType=Servlet,name=default,*/stateName",              None, [ "WebModule" ] ),
      # Check not yet working
      ( "*:j2eeType=Servlet,name=default,*/requestCount",           None, [ "WebModule" ]),
      ( "*:name=*,type=ThreadPool/maxThreads",                      None, []),
      ( "*:name=*,type=ThreadPool/currentThreadCount",              None, []),
      ( "*:name=*,type=ThreadPool/currentThreadsBusy",              None, []),
     # too wide location for addressing the right info
     # ( "*:j2eeType=Servlet,*/requestCount", None, [ "WebModule" ] ),
  ],
  "jboss" : [
      ( "*:type=Manager,*/activeSessions,maxActiveSessions",        None, [ "path", "context" ] ),
  ],
}


#   ( '*:j2eeType=WebModule,name=/--/localhost/-/%(app)s,*/state', None, [ "name" ]),
#   ( '*:j2eeType=Servlet,WebModule=/--/localhost/-/%(app)s,name=%(servlet)s,*/requestCount', None, [ "WebModule", "name" ]),
#   ( "Catalina:J2EEApplication=none,J2EEServer=none,WebModule=*,j2eeType=Servlet,name=*", None, [ "WebModule", "name" ]),


# List of instances to monitor. Each instance is a dict where
# the global configuration values can be overridden.
instances = [{}]

conffile = os.getenv("MK_CONFDIR", "/etc/check_mk") + "/jolokia.cfg"

if os.path.exists(conffile):
    execfile(conffile)

if instance == None:
    instance = str(port)

# We have to deal with socket timeouts. Python > 2.6
# supports timeout parameter for the urllib2.urlopen method
# but we are on a python 2.5 system here which seem to use the
# default socket timeout. We are local here so  set it to 1 second.
socket.setdefaulttimeout(1.0)

# Compute list of instances to monitor. If the user has defined
# instances in his configuration, we will use this (a list
# of dicts).
for inst in instances:
    for varname, value in [
        ( "protocol", protocol ),
        ( "server",   server ),
        ( "port",     port ),
        ( "user",     user ),
        ( "password", password ),
        ( "mode",     mode ),
        ( "suburi",   suburi ),
        ( "instance", instance ),
        ( "product",  product ),]:
        if varname not in inst:
            inst[varname] = value
    if not inst["instance"]:
        inst["instance"] = str(inst["port"])
    inst["instance"] = inst["instance"].replace(" ", "_")

    query_instance(inst)
