Class: Marionetta::CommandRunner

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(server) ⇒ CommandRunner

The most important requirement is `:logger`. All methods depend upon this property being set since `.system()` (the local command execution method) logs commands, outputs and fatal exceptions using it. It should implement the ruby stdlib `Logger` interface.

Other requirements will be listed with their appropriate methods.


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# File 'lib/marionetta/command_runner.rb', line 24

def initialize(server)
  @server = server
end

Instance Attribute Details

#lastObject (readonly)

The last command run by `.system()` is accessible via the `.last` attribute.


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# File 'lib/marionetta/command_runner.rb', line 92

def last
  @last
end

Instance Method Details

#archive(directory, save_to = nil) ⇒ Object

Create an archive of a local directory, optionally saving it to a directory or file path.


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# File 'lib/marionetta/command_runner.rb', line 70

def archive(directory, save_to = nil)
  if save_to.nil?
    save_to = "#{directory}.#{server[:archive][:ext]}"
  elsif File.directory?(save_to)
    dirname = File.basename(directory)
    save_to = "#{save_to}/#{dirname}.#{server[:archive][:ext]}"
  end

  archive_cmd = [
    server[:archive][:command],
    server[:archive][:flags],
    ['-f', save_to],
    ['-C', File.dirname(directory)],
    File.basename(directory),
  ]

  system(*archive_cmd.flatten)
end

#get(file_path, save_to = File.dirname(file_path), *additional_flags) ⇒ Object

Short hand for grabbing a file from `:hostname` saving to the same location on the local machine unless a path is specified.


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# File 'lib/marionetta/command_runner.rb', line 175

def get(file_path, save_to = File.dirname(file_path), *additional_flags)
  rsync("#{server[:hostname]}:#{file_path}", save_to, *additional_flags)
end

#put(file_path, save_to = File.dirname(file_path), *additional_flags) ⇒ Object

Short hand for putting a file to `:hostname` from the local machine to the same location on the remote machine unless a path is specified.


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# File 'lib/marionetta/command_runner.rb', line 183

def put(file_path, save_to = File.dirname(file_path), *additional_flags)
  rsync(file_path, "#{server[:hostname]}:#{save_to}", *additional_flags)
end

#rsync(from, to, *additional_flags) ⇒ Object

Using the rsync command copy one file system location to another. These may be both local or remote, or a mixture of the two.

Example:

rsync('/var/www/logs', '/var/backups/www/logs')
rsync('/var/www/logs', '[email protected]:/var/backups/www/logs')

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# File 'lib/marionetta/command_runner.rb', line 157

def rsync(from, to, *additional_flags)
  rsync_cmd = [server[:rsync][:command]]

  if server[:rsync].has_key?(:flags)
    flags = server[:rsync][:flags].clone
    flags.concat(additional_flags) unless additional_flags.empty?
    rsync_cmd << flags
  end
  
  rsync_cmd << [from, to]

  system(*rsync_cmd.flatten)
end

#ssh(command, &block) ⇒ Object

Requirements for remote executions `server` must be set along with `server[:command]`. Optionally `server[:flags]` can be used to pass in flags such as `-i` for setting SSH keys.

A block can be called against this method just like `.system()` in order to get `stdout` and `stderr`.

Example:

server = Marionetta.default_server
server[:hostname] = 'example.com'
server[:ssh][:flags] << ['-i', 'keys/private.key']

cmd = Marionetta::CommandRunner.new(server)
cmd.ssh('ls -l') do |out, err|
  puts out
end

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# File 'lib/marionetta/command_runner.rb', line 115

def ssh(command, &block)
  ssh_cmd = [server[:ssh][:command]]

  if server[:ssh].has_key?(:flags)
    ssh_cmd << server[:ssh][:flags]
  end

  ssh_cmd << server[:hostname]
  ssh_cmd << command

  system(*ssh_cmd.flatten, &block)
end

#ssh_extract(archive_path, save_to = File.dirname(archive_path)) ⇒ Object

Extract an archive, optionally to a specified directory on a remote machine.


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# File 'lib/marionetta/command_runner.rb', line 131

def ssh_extract(archive_path, save_to = File.dirname(archive_path))
  cmds = [
    "mkdir -p #{save_to}",
    "cd #{save_to}",
  ]

  extract_cmd = [
    server[:extract][:command],
    server[:extract][:flags],
    ['-f', archive_path],
  ]

  cmds << extract_cmd.flatten.join(' ')

  ssh(cmds.join(' && '))
end

#system(*args) ⇒ Object

Local commands are executed with `.system()`. We use `Open4::popen4` to capture the output of the command run neatly.

The command run is logged as info, output as debug and any exceptions thrown are sent as fatal.

You can optionally pass in a block which receives `stdout` and `stderr` as arguments:

cmd.system('ls ~') do |out, err|
  puts out
end

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# File 'lib/marionetta/command_runner.rb', line 44

def system(*args)
  @last = args.join(' ')
  server[:logger].info(last)

  begin
    status = Open4::popen4(*args) do |pid, stdin, stdout, stderr|
      yield stdout, stderr if block_given?

      [stdout, stderr].each do |io|
        io.each do |line|
          server[:logger].debug(line) unless line.empty?
        end
      end
    end
  rescue
    server[:logger].fatal(args.join(' '))
    server[:logger].fatal($!)
    exit(1)
  end

  return status.exitstatus == 0
end