Utilities and Helpers

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Engine comes packaged with some handy helper functions that make interfacing with the wide variety of common IoT protocols easier.
Functions and Constants
These can be included into your driver class
include ::Orchestrator::Constants
Helper
Type
Description
On, Down, Open
true
Constants that can make code more readable
Off, Up, Close, Short
false
Constants that can make code more readable
in_range(input_number, max, min = 0)
returns a number in the range
if input exceeds the limits, the limit is returned
is_affirmative? value
returns true if value is affirmative
values such as: true 'yes' :On
is_negatory? value
returns true if value is negative
values such as: false 'no' :Inactive
The Constants include module also contains Configuration Helpers
include ::Orchestrator::Transcoder
Helper
Type
Description
hex_to_byte(data)
returns binary string
accepts any string containing hex characters and supports common formatting such as "0xDEADBEEF", "De:ad:Be:ef" etc
byte_to_hex(data)
returns an ASCII string
accepts binary strings or arrays of bytes
str_to_array(data)
returns an array of bytes
accepts strings
array_to_str(data)
returns a binary string
accepts array of bytes
Protocols
WebSockets
Enables WebSocket communication using a standard TCP socket driver.
For more details on the websocket API see https://github.com/faye/websocket-driver-ruby#driver-api​
require 'protocols/websocket'
​
class WebsocketClient
    include ::Orchestrator::Constants
    include ::Orchestrator::Transcoder
​
    generic_name :Websocket
    descriptive_name 'Websocket example'
​
    tcp_port 80
    wait_response false
​
    def connected
        new_websocket_client
    end
​
    def disconnected
        # clear the keepalive ping
        schedule.clear
    end
​
    # Send a text message
    def some_request
        @ws.text "hello"
​
        # or json format etc
​
        @ws.text({
            some: "message",
            count: 234
        }.to_json)
    end
​
    # send a binary message
    def binary_send
        @ws.binary("binstring".bytes)
​
        # or
​
        @ws.binary hex_to_byte("0xdeadbeef")
    end
​
    protected
​
    def new_websocket_client
        # NOTE:: you must use wss:// when using port 443 (TLS connection)
        @ws = Protocols::Websocket.new(self, "ws://#{remote_address}/path/to/ws/endpoint")
        # @ws.add_extension # https://github.com/faye/websocket-extensions-ruby
        # @ws.set_header(name, value) # Sets a custom header to be sent as part of the handshake
        @ws.start
    end
​
    def received(data, resolve, command)
        @ws.parse(data)
        :success
    end
​
    # ====================
    # Websocket callbacks:
    # ====================
​
    # websocket ready
    def on_open
        logger.debug { "Websocket connected" }
        schedule.every('30s') do
            @ws.ping('keepalive')
        end
    end
​
    def on_message(raw_string)
        logger.debug { "received: #{raw_string}" }
​
        # Process request here
        # request = JSON.parse(raw_string)
        # ...
    end
​
    def on_ping(payload)
        logger.debug { "received ping: #{payload}" }
        # optional
    end
​
    def on_pong(payload)
        logger.debug { "received pong: #{payload}" }
        # optional
    end
​
    # connection is closing
    def on_close(event)
        logger.debug { "closing... #{event.code} #{event.reason}" }
    end
​
    # connection is closing
    def on_error(error)
        logger.debug { "ERROR! #{error.message}" }
    end
​
    # ====================
end
Telnet
Implements the telnet standard so that it is easy to communicate with devices that implement control codes or require negotiation.
require 'protocols/telnet'
​
class TelnetClient
    def on_load
        new_telnet_client
​
        # Telnet client returns only relevant data for buffering
        config before_buffering: proc { |data|
            @telnet.buffer data
        }
    end
​
    def disconnected
        # Ensures the buffer is cleared
        new_telnet_client
    end
​
​
    def some_request
        # Telnet deals with end of line characters
        # (may have been negotiated on initial connection)
        send @telnet.prepare('some request')
    end
​
    protected
​
    def new_telnet_client
        # Telnet client needs access to IO stream
        @telnet = Protocols::Telnet.new do |data|
            send data
        end
    end
end
KNX
Constructs KNX standard datagrams that make it easy to communicate with devices on KNX networks.
For more information see: https://github.com/acaprojects/ruby-knx​
BACnet
Constructs BACnet datagrams that make it easy to communicate with devices on BACnet networks.
For more information see: https://github.com/acaprojects/ruby-bacnet​
OAuth
For secure delegated access to services that implement it see wikipedia for details​
require 'protocols/oauth'
​
class HttpClient
    # =====================================
    # Hook into HTTP request via middleware
    # All requests will be sent with OAuth
    # =====================================
    def on_update
        connected
    end
​
    # This is called directly after on_load.
    # Middleware is not available until connected
    def connected
        @oauth = Protocols::OAuth.new({
            key:    setting(:consumer_key),
            secret: setting(:consumer_secret),
            site:   remote_address
        })
        update_middleware
    end
​
    protected
​
    def update_middleware
        # middleware is service helper function
        mid = middleware
        mid.clear
        mid << @oauth
    end
end
SNMP
Provides an evented IO proxy for ruby-netsnmp​
require 'protocols/snmp'
​
class SnmpClient
    include ::Orchestrator::Constants
    udp_port 161
​
    def on_unload
        @client.close
    end
​
    # This is called directly after on_load.
    # Middleware is not available until connected
    def connected
        proxy = Protocols::Snmp.new(self)
        @client = NETSNMP::Client.new({
            proxy: proxy, version: "2c",
            community: "public"
        })
    end
​
    def query_something
        self[:status] = @client.get(oid: '1.3.6.1.2.1.1.1.0')
    end
​
    def set_something(val)
        @client.set('1.3.6.1.2.1.1.3.0', value: val)
        self[:something] = val
    end
​
    protected
​
    def received(data, resolve, command)
        # return the data which resolves the request promise.
        # the proxy uses fibers to provide this to the NETSNMP client
        data
    end
end
SOAP Services
Probably the easiest way to use these services at the moment via a Logic module. There are a number of supported ruby gems:
​https://github.com/savonrb/savon​
​https://github.com/unwire/handsoap​
Savon usage:
# Ensure we are not blocking the IO reactor loop
require 'httpi/adapter/libuv'
require 'savon'
HTTPI.adapter = :libuv
​
# Make requests as per the savon documentation
client = Savon.client(wsdl: 'https://aca.im/service.wsdl')
logger.debug { "Available operations: #{client.operations}" }
Handsoap usage:
# Ensure we are not blocking the IO reactor loop
require 'handsoap/http/drivers/libuv_driver'
Handsoap.http_driver = :libuv
​
# Make requests as per the handsoap documentation
Wake on LAN
Wake on LAN is available to drivers of all types
# Supports any string with the correct number of hex digits
#  as well as common formats (these are some examples)
mac_address_string = '0x62f81d4b6f00'
mac_address_string = '62:f8:1d:4b:6f:00'
mac_address_string = '62-f8-1d-4b-6f-00'
​
# Defaults to broadcast address `'255.255.255.255'`
wake_device(mac_address_string)
​
# You can define a VLan gateway for a directed broadcast (most common in enterprise)
wake_device(mac_address_string, '192.168.3.1')
ICMP (ping)
Uses the operating systems ping utility to perform a connectivity check.
# perform the ping
ping = ::UV::Ping.new(remote_address)
ping.ping      # true / false to indicate success / failure
​
# check out the ping results
ping.pingable  # true / false to indicate success / failure
ping.ip        # IP pinged (remote_address can be a domain name)
ping.exception # any error messages
ping.warning   # any warning messages
CRC Checks
​github project and supported CRC checks​
gem install crc
Usage
require 'crc'
crc = CRC::CRC16_CCITT.new
crc.update "\x12\x34\x56\x78\x90"
crc.digest # => "ca"
Security
Next - Developer Guide
User Interfaces
Last modified 2yr ago
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On this page
Functions and Constants
Protocols
WebSockets
Telnet
KNX
BACnet
OAuth
SNMP
SOAP Services
Wake on LAN
ICMP (ping)
CRC Checks