Module: Shexy

Defined in:
lib/shexy.rb

Overview

Execute commands in remote servers (SSH)

require 'shexy'

Shexy.user = 'test'
Shexy.password = 'test'
Shexy.host = 'test-host'
out, err = Shexy.exe 'ls -la'
out.empty? # no output
err.empty? # no error output

Shexy.exe 'la -la' do |out,err|
  puts out
  puts err
end

Another way, assuming you are using SSH keys and added them to the SSH agent (ssh-add ~/.ssh/my-priv-key):

Shexy.exe 'test@test-host', 'ls -la' do |out, err|
  puts out
end
Shexy.exe 'echo hello' # no need to add host/user again

Copying files (local -> remote):

Shexy.copy_to 'test@test-host', '/home/rubiojr/my-uber-file', '/tmp/'

Constant Summary collapse

VERSION = 
'0.3.5'

Class Method Summary collapse

Class Method Details

.batch(&block) ⇒ Object 



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# File 'lib/shexy.rb', line 146

def self.batch(&block)
  require 'tempfile'
  def self.script(script)
    f = Tempfile.new 'shexy'
    begin
      f.puts script 
      f.flush
      copy_to f.path, "#{f.path}.remote"
      out, err, ecode, esig = exe "/bin/bash #{f.path}.remote" 
    ensure
      f.close
      f.unlink
    end
    return out, err, ecode, esig
  end
  instance_eval &block
end

.copy_ssh_pubkey(path, dest_dir = '~/.ssh') ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/shexy.rb', line 235

def self.copy_ssh_pubkey(path, dest_dir = '~/.ssh')
  path = File.expand_path path
  raise ArgumentError.new("Invalid key file") unless File.exist?(path)
  key = File.read path
  batch do
    script <<-EOH
    mkdir -p #{dest_dir} && chmod 700 #{dest_dir}
    echo '#{key}' >> #{dest_dir}/authorized_keys
    EOH
  end
end

.copy_to(*args) ⇒ Object

Shexy.copy_to ‘[email protected]’, ‘source_file’, ‘dest_file’

or

Shexy.host = ‘foobar.com’ Shexy.user = ‘root’ Shexy.copy_to ‘source_file’, ‘dest_file’



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# File 'lib/shexy.rb', line 173

def self.copy_to(*args)
  opts = {}
  if args.include?(:recursive)
    opts = { :recursive => true }
    args.delete :recursive
  end
  
  if args.size > 2
    # First arg assumed to be [email protected]
    self.host = args[0]
    if self.host =~ /@/
      self.user, self.host = self.host.split '@'
    end
    from = args[1]
    to = args[2]
  else
    # user, host already set via Shexy.host and
    # Shexy.user
    from = args[0]
    to = args[1]
  end
  self.flags[:password] = self.password if self.password
  from = File.expand_path from
  Net::SCP.start(host, user, flags) do |scp|
    scp.upload! from, to, opts
  end
end

.distro ⇒ Object

Detect distro version



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# File 'lib/shexy.rb', line 204

def self.distro
  issue.match(/fedora|centos|frameos|debian|ubuntu|scientific linux/i)[0].gsub(" ", "_").downcase.to_sym
end

.distro_release ⇒ Object

Detect distro release



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# File 'lib/shexy.rb', line 211

def self.distro_release
  case distro 
  when :redhat,:centos,:frameos
    issue.split[2]
  when :fedora
    issue.split[2]
  when :ubuntu
    issue.split[1]
  when :debian
    issue.split[2]
  else
    '0'
  end
end

.exe(*args) ⇒ Object 



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# File 'lib/shexy.rb', line 83

def self.exe(*args)
  args.flatten!
  if args.size > 1
    self.host = args[0]
    self.user, self.host = self.host.split '@' if self.host =~ /@/
    self.cmd = args[1]
  else
    self.cmd = args[0]
  end
  self.flags[:password] = self.password if self.password
  self.flags[:keys] = [self.key] if self.key
  Net::SSH.start(self.host, self.user, self.flags) do |sh|
    sh.open_channel do |ch| 
      #
      # Note, too, that when a pty is requested, user's shell configuration 
      # scripts (.bashrc and such) are not run by default, 
      # whereas they are run when a pty is not present.
      #
      # http://net-ssh.github.com/net-ssh/classes/Net/SSH/Connection/Channel.html#method-i-request_pty
      #
      # FIXME: may not be successful, warn about it
      ch.request_pty 
      if sudo?
        regexp = /(&&|\|\||&|\|)/
        if cmd =~ regexp
          new_cmd = cmd.split(regexp).map do |t| 
            t =~ /^(&&|\|\||&|\|)$/ ? t : "sudo #{t}"
          end
          self.cmd = new_cmd.join ''
        end
        self.cmd = "sudo #{cmd}"
        puts "SHEXY: #{cmd}" if $DEBUG
      end
      ch.exec cmd do
        # FIXME: I don't think it's a good idea
        # to implement access to stdout,stderr this way
        stdout = ""
        stderr = ""
        exit_code = -1
        exit_signal = -1
        ch.on_extended_data do |c2, type, data|
          # ERROR output here
          stderr << data
          yield nil, data if block_given?
        end
        ch.on_data do |c2, data|
          stdout << data
          yield data, nil if block_given?
        end
        ch.on_close do |c2|
          return stdout, stderr, exit_code, exit_signal
        end
        ch.on_request("exit-status") do |c2,data|
          exit_code = data.read_long
        end
        ch.on_request("exit-signal") do |c2, data|
          exit_signal = data.read_long
        end
      end
    end
  end
end

.flags ⇒ Object 



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# File 'lib/shexy.rb', line 46

def self.flags; Thread.current[:shexy_flags] ||= {} ; end

.flags=(f) ⇒ Object 



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# File 'lib/shexy.rb', line 45

def self.flags=(f);Thread.current[:shexy_flags] = f;end

.issue ⇒ Object

Lame but short, and it works (most of the times)



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# File 'lib/shexy.rb', line 229

def self.issue
  issue, err = ((exe 'cat /etc/issue')[0].strip.chomp || Shexy.exe('lsb_release -i')[0].strip.chomp).lines.first
  raise Exception.new "Error reading release info." unless (err.nil? or err.empty?)
  issue
end

.permit_root_login(value) ⇒ Object

Set PermitRootLogin to value in /etc/ssh/sshd_config value accepted: yes,now, without-password



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# File 'lib/shexy.rb', line 251

def self.(value)
  value = value.to_s
  unless value =~ /^(yes|no|without-password)$/
    raise ArgumentError.new "Argument should be yes|no|without-password"
  end

  using_sudo = Shexy.sudo?
  Shexy.use_sudo unless Shexy.user == 'root'
  out, err = batch do
    script <<-EOH
    sed -i 's/^#\\?PermitRootLogin.*$/PermitRootLogin\\ #{value}/' /etc/ssh/sshd_config
    test -f /etc/init.d/ssh && /etc/init.d/ssh restart
    test -f /etc/init.d/sshd && /etc/init.d/sshd restart
    EOH
  end
  Shexy.use_sudo(false) unless using_sudo
  return out, err
end

.script(script) ⇒ Object 



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# File 'lib/shexy.rb', line 148

def self.script(script)
  f = Tempfile.new 'shexy'
  begin
    f.puts script 
    f.flush
    copy_to f.path, "#{f.path}.remote"
    out, err, ecode, esig = exe "/bin/bash #{f.path}.remote" 
  ensure
    f.close
    f.unlink
  end
  return out, err, ecode, esig
end

.sudo? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/shexy.rb', line 47

def self.sudo?;Thread.current[:shexy_use_sudo]; end

.tcp_test_ssh ⇒ Object 



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# File 'lib/shexy.rb', line 65

def self.tcp_test_ssh
  tcp_socket = TCPSocket.new(host, 22)
  readable = IO.select([tcp_socket], nil, nil, 5)
  if readable
    yield
    true
  else
    false
  end
rescue Errno::ETIMEDOUT, Errno::EPERM
  false
rescue Errno::ECONNREFUSED, Errno::EHOSTUNREACH, Errno::ENETUNREACH
  sleep 2
  false
ensure
  tcp_socket && tcp_socket.close
end

.use_sudo(v = true) ⇒ Object 



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# File 'lib/shexy.rb', line 48

def self.use_sudo(v = true); Thread.current[:shexy_use_sudo] = v; end

.wait_for_ssh(timeout = 60) ⇒ Object 



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# File 'lib/shexy.rb', line 50

def self.wait_for_ssh(timeout = 60)
  Timeout.timeout(timeout) do
    begin
      sleep(1) until tcp_test_ssh do
      end
    rescue Errno::ECONNRESET
      # safe to ignore, we need to retry all the time.
    end
  end
  true
rescue Exception => e
  $stderr.puts e.message
  false
end