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Utilities and Helpers

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.

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:

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"
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