Class: PolySSH::CommandBuilder

Inherits:
Object
  • Object
show all
Includes:
VisitorBase
Defined in:
lib/polyssh/command_builder.rb

Instance Method Summary collapse

Methods included from VisitorBase

#do_visit

Constructor Details

#initialize ⇒ CommandBuilder

Returns a new instance of CommandBuilder.



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# File 'lib/polyssh/command_builder.rb', line 6

def initialize 
  @commands = []
  @last_command = ""
  @baseport = 18000 + rand(2000)
end

Instance Method Details

#get_port ⇒ Object

Detect next available port



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# File 'lib/polyssh/command_builder.rb', line 60

def get_port
  @baseport += 1
  while !port_open?(@baseport) do  
    @baseport += 1
  end
end

#port_open?(port) ⇒ Boolean

Test if given port is locally used

Returns:

  • (Boolean) 


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# File 'lib/polyssh/command_builder.rb', line 68

def port_open?(port)
    !system("lsof -i:#{port}", out: '/dev/null')
end

#visit_polyssh_nodeentry(node_entry) ⇒ Object

Visit each node entry



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# File 'lib/polyssh/command_builder.rb', line 20

def visit_polyssh_nodeentry node_entry
  cmd=""
  if @commands.empty? and node_entry.next.nil? then
    cmd = ("ssh " +
           "-o ForwardAgent=yes " +
           "-o UserKnownHostsFile=/dev/null " +
           "-o StrictHostKeyChecking=no " +
           "-p #{node_entry.port} " +
           "-l #{node_entry.user} " +
           "#{node_entry.host} " 
          )
    @commands << [@baseport, cmd]
  elsif node_entry.next.nil? then
    cmd = ("ssh " +
           "-o ForwardAgent=yes " +
           "-o UserKnownHostsFile=/dev/null " +
           "-o StrictHostKeyChecking=no " +
           "-p #{@baseport} " +
           "-l #{node_entry.user} " +
           "localhost " 
          )
    @commands << [@baseport, cmd]
  else
    get_port
    next_entry = node_entry.next 
    cmd = (
      "ssh " +
      "-o ForwardAgent=yes " +
      "-o UserKnownHostsFile=/dev/null " +
      "-o StrictHostKeyChecking=no " +
      "-N " +
      "-L#{@baseport}:#{next_entry.host}:#{next_entry.port} " +
      "-l #{node_entry.user} #{node_entry.host} "
    )
    @commands << [@baseport, cmd]
    next_entry.accept(self)
  end
end

#visit_polyssh_nodelist(node_list) ⇒ Object

Visit node list



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# File 'lib/polyssh/command_builder.rb', line 13

def visit_polyssh_nodelist node_list
    if node_list.count > 0 then
      node_list.first.accept(self)
    end
end