MQTT for Sysadmins

Transcript

1. MQTT for sysadmins and for fun Jan-Piet Mens April 2014 @jpmens
2. @jpmens: consultant, author, architect, part-time admin, small-scale fiddler, loves LDAP, DNS, plain text, and things that work.
3. MQTT is a standard, a transport, PUB/SUB messaging, designed for unreliable networks
4. transport protocol binary payload, 256MB, (+2 bytes) , fast, lightweight, ideal for low- bandwith, high-latency networks
5. security TLS authentication ACLs TLS-PSK (payload encryption)
6. Quality of Service 0 At most once 1 Assured delivery 2 Once only
7. more features keepalive last will & testament
8. compare HTTP ? request/response, verbose, push, poll, nobody hears clients die
9. PUB/SUB decoupled senders recipients: flexibility one producer to many (changing) consumers no queueing broker can hold messages until subscriber reconnects durable (retain) Last Will and Testament single TCP port (easy on firewalls)
10. topic names UTF-8, hierarchical, wildcards temperature/room/living devices/# finance/+/eur/rate
11. PUB/SUB cauldron
12. MQTT brokers the server bit of MQTT
13. Mosquitto C, fast, lightweight, ACLs (plugin), TLS, TLS-PSK, bridge, logging via $SYS http://mosquitto.org
14. HiveMQ Java, plugins, Websockets, clustering, modules http://hivemq.com
15. more brokers RSMB, Mosca, Apollo, RabbitMQ
16. MQTT brokers $SYS topic $SYS/broker/clients/total 1771 $SYS/broker/messages/received 36597465 $SYS/broker/messages/sent 39714120 $SYS/broker/messages/stored 2941 $SYS/broker/bytes/received 2830787008 $SYS/broker/bytes/sent 3810653433 $SYS/broker/version mosquitto version 1.2 $SYS/broker/publish/messages/received 19798673 $SYS/broker/publish/messages/sent 30622855 $SYS/broker/publish/bytes/received 1868229299 $SYS/broker/publish/bytes/sent 3185942282
17. bridging
18. CLI utilities mosquitto_sub -v [-h localhost] [-p 1883] [--cafile file] [--cert file --key file] [-u username [-P password]] [ --tls-version tlsv1.2 ] -t 'topic/#' subscribe publish mosquitto_pub ... [-r] -m payload
19. languages Lua, Python, C, JavaScript, Perl, Ruby, Java, ...
20. Python API: PUB #!/usr/bin/env python import paho.mqtt.publish as mqtt mqtt.single('conf/hello', 'Hello MQTT') $ mosquitto_sub -h localhost -v -t 'conf/#' conf/hello Hello MQTT payload topic
21. Python API: SUB #!/usr/bin/env python import paho.mqtt.client as paho def on_connect(mosq, userdata, rc): mqttc.subscribe("conf/+", 0) def on_message(mosq, userdata, msg): print "%s %s" % (msg.topic, str(msg.payload)) mqttc = paho.Client() mqttc.on_connect = on_connect mqttc.on_message = on_message mqttc.connect("localhost", 1883, 60) mqttc.loop_forever() callbacks
22. Python API: SUB $ mosquitto_pub -t 'conf/thirsty' -m 'Beertime?' $ mosquitto_pub -t 'conf/catering' -m 'Coffee is ready' $ ./sub.py conf/thirsty Beertime? conf/catering Coffee is ready
23. devices
24. devices
25. practical solutions alerting, metering, logging, location awareness, tracking, automation, and controlling
26. MQTT out there Github (notifications), power metering, trains, FaceBook messenger, connected cars, temperature monitoring, host monitoring (load)
27. system utilities Ansible (notifications), Fluentd (logging), Diamond (system metrics), mqtt-watchdir, Jenkins, (build logs),
28. database persistence SUB and store in any SQL or NoSQL database
29. alerting: mqttwarn https://github.com/jpmens/mqttwarn
30. job control, reporting https://gist.github.com/jpmens/7101170 $ mosquitto_sub -v -t 'processes/#' processes/run.sh Starting processes/run.sh Still running processes/monitor/spec1 Starting processes/run.sh Still going strong at Tue Oct 22 15:49:07 CEST 2013 processes/run.sh That's it, folks!
31. WebSockets HiveMQ, WSS, lighttpd mod_websocket
32. WebSockets http://www.hivemq.com/demos/websocket-client/
35. Node-RED http://nodered.org
36. mqtt.org @mqttorg