Class: Arachni::RPC::Server::Dispatcher::Node

Inherits:
Object
  • Object
show all
Includes:
UI::Output
Defined in:
lib/arachni/rpc/server/dispatcher/node.rb

Overview

Dispatcher node class, helps maintain a list of all available Dispatchers in the grid and announce itself to neighbouring Dispatchers.

As soon as a new Node is fired up it checks-in with its neighbour and grabs a list of all available peers.

As soon as it receives the peer list it then announces itself to them.

Upon convergence there will be a grid of Dispatchers each one with its own copy of all available Dispatcher URLs.

Author:

Constant Summary collapse

DEFAULT_PING_INTERVAL = 
60

Instance Method Summary collapse

Methods included from UI::Output

#debug?, #debug_off, #debug_on, #disable_only_positives, #error_logfile, #flush_buffer, #log_error, #mute, #muted?, old_reset_output_options, #only_positives, #only_positives?, #print_bad, #print_debug, #print_debug_backtrace, #print_debug_pp, #print_error, #print_error_backtrace, #print_info, #print_line, #print_ok, #print_status, #print_verbose, #reroute_to_file, #reroute_to_file?, reset_output_options, #set_buffer_cap, #set_error_logfile, #uncap_buffer, #unmute, #verbose, #verbose?

Constructor Details

#initialize(opts, logfile = nil) ⇒ Node

Initializes the node by:

* Adding the neighbour (if the user has supplied one) to the peer list.
* Getting the neighbour's peer list and appending them to its own.
* Announces itself to the neighbour and instructs it to propagate our URL
  to the others.

Parameters:



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# File 'lib/arachni/rpc/server/dispatcher/node.rb', line 53

def initialize( opts, logfile = nil )
    @opts = opts
    @opts.rpc_external_address ||= @opts.rpc_address

    @url = "#{@opts.rpc_external_address}:#{@opts.rpc_port}"

    reroute_to_file( logfile ) if logfile

    print_status 'Initializing grid node...'

    @dead_nodes = []
    @neighbours = Set.new
    @nodes_info_cache = []

    if (neighbour = @opts.neighbour)
        # add neighbour and announce him to everyone
        add_neighbour( neighbour, true )

        # grab the neighbour's neighbours
        peer = connect_to_peer( neighbour )
        peer.neighbours do |urls|
            fail "Neighbour '#{neighbour}' is unreachable." if urls.rpc_exception?
            urls.each { |url| @neighbours << url if url != @url }
        end
    end

    print_status( 'Node ready.' )

    log_updated_neighbours

    interval = @opts.node_ping_interval || DEFAULT_PING_INTERVAL
    ::EM.add_periodic_timer( interval ) do
        ping
        check_for_comebacks
    end
end

Instance Method Details

#add_neighbour(node_url, propagate = false) ⇒ Object

Adds a neighbour to the peer list.

Parameters:

  • node_url (String) —

    URL of a neighbouring node.

  • propagate (Boolean) (defaults to: false) —

    Whether or not to announce the new node to the peers.



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# File 'lib/arachni/rpc/server/dispatcher/node.rb', line 102

def add_neighbour( node_url, propagate = false )
    # we don't want ourselves in the Set
    return false if node_url == @url
    return false if @neighbours.include?( node_url )

    print_status "Adding neighbour: #{node_url}"

    @neighbours << node_url
    log_updated_neighbours
    announce( node_url ) if propagate

    connect_to_peer( node_url ).add_neighbour( @url, propagate ) do |res|
        next if !res.rpc_exception?
        add_dead_neighbour( node_url )
        print_status "Neighbour seems dead: #{node_url}"
    end
    true
end

#alive? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/arachni/rpc/server/dispatcher/node.rb', line 175

def alive?
    true
end

#grid_member? ⇒ Boolean

Returns ‘true` if grid member, `false` otherwise.

Returns:

  • (Boolean) —

    ‘true` if grid member, `false` otherwise.



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# File 'lib/arachni/rpc/server/dispatcher/node.rb', line 91

def grid_member?
    @neighbours.any?
end

#info ⇒ Hash

Returns * ‘:url` – This node’s URL.

  • ‘:pipe_id` – Bandwidth Pipe ID

  • ‘:weight` – Weight

  • ‘:nickname` – Nickname

  • ‘:cost` – Cost.

Returns:

  • (Hash) —

    • ‘:url` – This node’s URL.

    • ‘:pipe_id` – Bandwidth Pipe ID

    • ‘:weight` – Weight

    • ‘:nickname` – Nickname

    • ‘:cost` – Cost



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# File 'lib/arachni/rpc/server/dispatcher/node.rb', line 165

def info
    {
        'url'      => @url,
        'pipe_id'  => @opts.pipe_id,
        'weight'   => @opts.weight,
        'nickname' => @opts.nickname,
        'cost'     => @opts.cost
    }
end

#neighbours ⇒ Array

Returns Neighbour/node/peer URLs.

Returns:

  • (Array) —

    Neighbour/node/peer URLs.



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# File 'lib/arachni/rpc/server/dispatcher/node.rb', line 122

def neighbours
    @neighbours.to_a
end

#neighbours_with_info(&block) ⇒ Object 



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# File 'lib/arachni/rpc/server/dispatcher/node.rb', line 126

def neighbours_with_info( &block )
    fail 'This method requires a block!' if !block_given?

    @neighbours_cmp = ''

    if @nodes_info_cache.empty? || @neighbours_cmp != neighbours.to_s
        @neighbours_cmp = neighbours.to_s

        each = proc do |neighbour, iter|
            connect_to_peer( neighbour ).info do |info|
                if info.rpc_exception?
                    print_info "Neighbour seems dead: #{neighbour}"
                    add_dead_neighbour( neighbour )
                    log_updated_neighbours

                    iter.return( nil )
                else
                    iter.return( info )
                end
            end
        end

        after = proc do |nodes|
            @nodes_info_cache = nodes.compact
            block.call( @nodes_info_cache )
        end

        ::EM::Iterator.new( neighbours ).map( each, after )
    else
        block.call( @nodes_info_cache )
    end
end