websocket

WebSocket example

Try this example here

This example demonstrates the use of services from browsers using WebSockets.

To run this example start the worker pool:

cd beekeper/examples/websocket
source setup.sh
./run.sh

Then open client.html in a browser (the JSON-RPC traffic will be dumped on browser console).

Or use the command line client:

./client.pl

Monitor the worker pool load:

bkpr-top

Logs can be inspected with bkpr-log or with:

tail /var/log/myapp-pool.log
tail /var/log/myapp-service-calculator.log
tail /var/log/beekeeper-service-router.log

Finally stop the worker pool with:

./run.sh stop

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Mosquitto setup

This example uses the internal ToyBroker to allow being run out of the box, but to use actual WebSockets from client.html a real broker like Mosquitto is required (client.pl works fine with ToyBroker though).

To run this example on a fresh install of Mosquitto set use_toybroker to false in config file pool.config.json. Then follow the instructions below to quickly setup a Mosquitto instance capable of running Beekeper applications with minimal security.

Please note that the entire idea is to have the backend and frontend buses serviced by different broker instances, running on isolated servers. This setup uses a single broker instance for simplicity, and works just because topics do not clash (see Brokers.md for a proper configuration).

Create /etc/mosquitto/examples.conf

per_listener_settings   true
max_queued_messages     10000
set_tcp_nodelay         true

## Backend

listener            1883  127.0.0.1
protocol            mqtt
max_qos             1
persistence         false
retain_available    false
allow_anonymous     false
acl_file            /etc/mosquitto/backend.acl
password_file       /etc/mosquitto/backend.users

## Frontend

listener            11883  0.0.0.0
protocol            mqtt
max_qos             1
persistence         false
retain_available    false
allow_anonymous     false
acl_file            /etc/mosquitto/frontend.acl
password_file       /etc/mosquitto/frontend.users

## Frontend WebSocket

listener            18080  0.0.0.0
protocol            websockets
max_qos             1
persistence         false
retain_available    false
allow_anonymous     false
acl_file            /etc/mosquitto/frontend.acl
password_file       /etc/mosquitto/frontend.users

Create /etc/mosquitto/backend.acl

pattern  read   priv/%c/#

user backend

topic   readwrite   msg/#
topic   readwrite   req/#
topic   readwrite   res/#
topic   readwrite   log/#
topic   write       priv/#

Create /etc/mosquitto/frontend.acl

pattern  read   priv/%c

user frontend

topic   read    msg/#
topic   write   req/#

user router

topic   write   msg/#
topic   read    req/#
topic   write   priv/#

Create broker users running the following commands:

mosquitto_passwd -c -b /etc/mosquitto/backend.users   backend   def456
mosquitto_passwd -c -b /etc/mosquitto/frontend.users  frontend  abc123
mosquitto_passwd    -b /etc/mosquitto/frontend.users  router    ghi789

Then the Mosquitto broker instance can be started with:

mosquitto -c /etc/mosquitto/examples.conf

If the broker is running elsewhere than localhost edit bus.config.json and config.js accordingly.

Detailed Mosquitto install instructions can be found here

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Acknowledgements

This software uses the following library:

• MQTT.js - https://github.com/mqttjs/MQTT.js
  Released under the terms of the MIT license