Class: MultiSSH

Inherits:
Object
  • Object
show all
Defined in:
lib/multi_ssh.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(amazon, group_name, deploy_group, concurrent_max = 1000) ⇒ MultiSSH

Returns a new instance of MultiSSH.



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# File 'lib/multi_ssh.rb', line 8

def initialize(amazon, group_name, deploy_group, concurrent_max = 1000)
  @amazon = amazon
  @group_name = group_name
  @deploy_group = deploy_group
  @group_config = deploy_group.config
  @concurrent_max = concurrent_max
  @session = nil
  @ui = Printer.new(STDOUT, STDERR, STDIN)
end

Instance Attribute Details

#amazon ⇒ Object (readonly)

Returns the value of attribute amazon.



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# File 'lib/multi_ssh.rb', line 5

def amazon
  @amazon
end

#concurrent_max ⇒ Object

Returns the value of attribute concurrent_max.



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# File 'lib/multi_ssh.rb', line 6

def concurrent_max
  @concurrent_max
end

#deploy_group ⇒ Object (readonly)

Returns the value of attribute deploy_group.



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# File 'lib/multi_ssh.rb', line 5

def deploy_group
  @deploy_group
end

#group_config ⇒ Object (readonly)

Returns the value of attribute group_config.



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# File 'lib/multi_ssh.rb', line 5

def group_config
  @group_config
end

#group_name ⇒ Object (readonly)

Returns the value of attribute group_name.



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# File 'lib/multi_ssh.rb', line 5

def group_name
  @group_name
end

#instances ⇒ Object

Returns the value of attribute instances.



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# File 'lib/multi_ssh.rb', line 6

def instances
  @instances
end

#longest ⇒ Object

Returns the value of attribute longest.



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# File 'lib/multi_ssh.rb', line 6

def longest
  @longest
end

#ui ⇒ Object

Returns the value of attribute ui.



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# File 'lib/multi_ssh.rb', line 6

def ui
  @ui
end

Instance Method Details

#add_output(host, msg) ⇒ Object 



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# File 'lib/multi_ssh.rb', line 94

def add_output(host, msg)
  # see if we already have an entry for this host
  data_array = output_tracker[host]
  if data_array.nil?
    data_array = []
    output_tracker[host] = data_array
  end
  # now add the msg to the array
  data_array << msg
end

#clear_session ⇒ Object 



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# File 'lib/multi_ssh.rb', line 70

def clear_session
  @session = nil
  # a map that tracks all output data in an array
  # keyed by the host name
  @output_tracker = {}
end

#find_instance_by_host(host) ⇒ Object

find a matching instance for the specified host



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# File 'lib/multi_ssh.rb', line 61

def find_instance_by_host(host)
  self.instances.each do |instance|
    if instance[:public_hostname] == host
      return instance
    end
  end
  return nil
end

#output_tracked_data_to_files(prefix, result_path) ⇒ Object

dump the result data into a file for each host



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# File 'lib/multi_ssh.rb', line 82

def output_tracked_data_to_files(prefix, result_path)
  return if result_path.nil?
  output_tracker.each do |key, data|
    file_path = File.expand_path('.', "#{result_path}/results_#{prefix}_#{key}.txt")
    File.open(file_path, 'w') do |f|
      data.each do |line|
        f.puts(line)
      end
    end
  end
end

#output_tracker ⇒ Object 



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# File 'lib/multi_ssh.rb', line 77

def output_tracker
  @output_tracker
end

#print_data(host, data, color = :cyan) ⇒ Object

print and group data by host



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# File 'lib/multi_ssh.rb', line 120

def print_data(host, data, color = :cyan)
  if data =~ /\n/
    data.split(/\n/).each { |d| print_data(host, d) }
  else
    add_output(host, data)
    padding = self.longest - host.length
    str = ui.color(host, color) + (" " * (padding + 1)) + data
    ui.msg(str)
  end
end

#run(remote_cmd) ⇒ Object 



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# File 'lib/multi_ssh.rb', line 18

def run(remote_cmd)
  @instances ||= amazon.find_and_sort_named_instances(group_name)
  run_instances(@instances, remote_cmd)
end

#run_instances(instances, remote_cmd) ⇒ Object 



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# File 'lib/multi_ssh.rb', line 23

def run_instances(instances, remote_cmd)
  clear_session
  @longest = 0
  @instances = instances
  @instances.each do |instance|
    session_opts = {}
    host = instance[:public_hostname]
    session_opts[:keys] = File.expand_path("~/.ssh/#{group_config[:amazon_security_key]}.pem")
    session_opts[:paranoid] = false
    session_opts[:user_known_hosts_file] = "/dev/null"
    session_opts[:timeout] = 30
    hostspec = "ec2-user@#{host}"
    session.use(hostspec, session_opts)

    @longest = host.length if host.length > @longest
  end

  ssh_command(remote_cmd, session)

  result = 0
  failed_count = 0
  @instances.each do |instance|
    ssh_result = instance[:ssh_exit_status]
    if ssh_result != 0
      failed_count += 1
      result = ssh_result if result == 0
    end
  end

  if failed_count > 0
    raise "Failed SSH command.  Out of #{@instances.count} servers, #{failed_count} failed.  First error was: #{result}"
  else
    ui.msg(ui.color("All #{@instances.count} ssh requests completed without error.", :green, :bold))
  end
end

#session ⇒ Object 



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# File 'lib/multi_ssh.rb', line 105

def session
  return @session unless @session.nil?

  ssh_error_handler = Proc.new do |server|
    host = server.host
    msg = "Failed to connect to #{host} -- #{$!.class.name}: #{$!.message}"
    print_data(host, msg, :red)
    instance = find_instance_by_host(host)
    instance[:ssh_exit_status] = 99
  end

  @session ||= Net::SSH::Multi.start(:concurrent_connections => concurrent_max, :on_error => ssh_error_handler)
end

#ssh_command(command, subsession) ⇒ Object 



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# File 'lib/multi_ssh.rb', line 131

def ssh_command(command, subsession)
  subsession.open_channel do |ch|
    ch.request_pty
    ch.exec command do |ch, success|
      raise ArgumentError, "Cannot execute #{command}" unless success
      ch.on_data do |ichannel, data|
        print_data(ichannel[:host], data)
      end
      ch.on_extended_data do |ichannel, type, data|
        print_data(ichannel[:host], data, :red)
      end
      ch.on_request("exit-status") do |ichannel, data|
        status = data.read_long
        ichannel[:exit_status] = status
        host = ichannel[:host]
        instance = find_instance_by_host(host)
        instance[:ssh_exit_status] = status
        print_data(host, "Exit status is: #{status}", status == 0 ? :blue : :red)
      end
    end
  end
  session.loop
end