Initial import of check_mqtt

From upstream
<https://github.com/jpmens/check-mqtt/blob/master/check-mqtt.py>

diff --git a/plugins/check_mqtt b/plugins/check_mqtt
new file mode 100755 (executable)
index 0000000..395f703
--- /dev/null
+++ b/plugins/check_mqtt
@@ -0,0 +1,144 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2013-2015 Jan-Piet Mens <jpmens()gmail.com>
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice,
+#    this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+# 3. Neither the name of mosquitto nor the names of its
+#    contributors may be used to endorse or promote products derived from
+#    this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+
+import paho.mqtt.client as paho
+import ssl
+import time
+import sys
+import os
+import argparse
+
+check_payload = 'PiNG'
+
+status = 0
+message = ''
+
+nagios_codes = [ 'OK', 'WARNING', 'CRITICAL', 'UNKNOWN' ]
+
+def on_connect(mosq, userdata, rc):
+    """
+    Upon successfully being connected, we subscribe to the check_topic
+    """
+
+    mosq.subscribe(args.check_topic, 0)
+
+def on_publish(mosq, userdata, mid):
+    pass
+
+def on_subscribe(mosq, userdata, mid, granted_qos):
+    """
+    When the subscription is confirmed, we publish our payload
+    on the check_topic. Since we're subscribed to this same topic,
+    on_message() will fire when we see that same message
+    """
+
+    (res, mid) =  mosq.publish(args.check_topic, check_payload, qos=2, retain=False)
+
+def on_message(mosq, userdata, msg):
+    """
+    This is invoked when we get our own message back. Verify that it
+    is actually our message and if so, we've completed a round-trip.
+    """
+
+    global message
+    global status
+
+    if str(msg.payload) == check_payload:
+        userdata['have_response'] = True
+        status = 0
+        elapsed = (time.time() - userdata['start_time'])
+        message = "PUB to %s at %s responded in %.2f" % (args.check_topic, args.mqtt_host, elapsed)
+
+def on_disconnect(mosq, userdata, rc):
+
+    if rc != 0:
+        exitus(1, "Unexpected disconnection. Incorrect credentials?")
+
+def exitus(status=0, message="all is well"):
+    """
+    Produce a Nagios-compatible single-line message and exit according
+    to status
+    """
+
+    print "%s - %s" % (nagios_codes[status], message)
+    sys.exit(status)
+
+
+parser = argparse.ArgumentParser()
+parser.add_argument('-H', '--host', metavar="<hostname>", help="mqtt host to connect to (defaults to localhost)", dest='mqtt_host', default="localhost")
+parser.add_argument('-P', '--port', metavar="<port>", help="network port to connect to (defaults to 1883)", dest='mqtt_port', default=1883, type=int)
+parser.add_argument('-u', '--username', metavar="<username>", help="username", dest='mqtt_username', default=None)
+parser.add_argument('-p', '--password', metavar="<password>", help="password", dest='mqtt_password', default=None)
+parser.add_argument('-t', '--topic', metavar="<topic>", help="topic to use for the check (defaults to nagios/test)", dest='check_topic', default='nagios/test')
+parser.add_argument('-m', '--max-wait', metavar="<seconds>", help="maximum time to wait for the check (defaults to 4 seconds)", dest='max_wait', default=4, type=int)
+args = parser.parse_args()
+
+userdata = {
+    'have_response' : False,
+    'start_time'    : time.time(),
+}
+mqttc = paho.Client('nagios-%d' % (os.getpid()), clean_session=True, userdata=userdata, protocol=4)
+mqttc.on_message = on_message
+mqttc.on_connect = on_connect
+mqttc.on_disconnect = on_disconnect
+mqttc.on_publish = on_publish
+mqttc.on_subscribe = on_subscribe
+
+#mqttc.tls_set('root.ca',
+#    cert_reqs=ssl.CERT_REQUIRED,
+#    tls_version=1)
+
+#mqttc.tls_set('root.ca', certfile='c1.crt', keyfile='c1.key', cert_reqs=ssl.CERT_REQUIRED, tls_version=3, ciphers=None)
+#mqttc.tls_insecure_set(True)    # optional: avoid check certificate name if true
+
+# username & password may be None
+if args.mqtt_username is not None:
+    mqttc.username_pw_set(args.mqtt_username, args.mqtt_password)
+
+# Attempt to connect to broker. If this fails, issue CRITICAL
+
+try:
+    mqttc.connect(args.mqtt_host, args.mqtt_port, 60)
+except Exception, e:
+    status = 2
+    message = "Connection to %s:%d failed: %s" % (args.mqtt_host, args.mqtt_port, str(e))
+    exitus(status, message)
+
+rc = 0
+while userdata['have_response'] == False and rc == 0:
+    rc = mqttc.loop()
+    if time.time() - userdata['start_time'] > args.max_wait:
+        message = 'timeout waiting for PUB'
+        status = 2
+        break
+
+mqttc.disconnect()
+
+exitus(status, message)
+