ssh_helpers.rb View source

Helpers: SSH helpers

You don't need to invoke these helpers, they're already invoked automatically.

 
module Mina
  module SshHelpers

ssh

Executes a command via SSH.

Returns nothing usually, but if { return: true } is given, returns the STDOUT output of the SSH session.

options is a hash of options:

  • :pretty - Prettify the output if true.
  • :return - If set to true, returns the output.

Example

ssh("ls", return: true)

    def ssh(cmd, options={})
      require 'shellwords'

      cmd = cmd.join("\n")  if cmd.is_a?(Array)
      script = Shellwords.escape(cmd)

      if options[:return] == true
        `#{ssh_command} -- #{script}`

      elsif simulate_mode?
        Ssh.simulate(cmd, ssh_command)

      else
        result = Ssh.invoke(script, self)
        Ssh.ensure_successful result, self
      end
    end

ssh_command

Returns the SSH command to be executed.

set :domain, 'foo.com'
set :user, 'diggity'

puts ssh_command
#=> 'ssh diggity@foo.com'

    def ssh_command
      args = domain!.dup
      args = "#{user}@#{args}" if user?
      args << " -i #{identity_file}" if identity_file?
      args << " -p #{port}" if port?
      args << " -A" if forward_agent?
      args << " #{ssh_options}"  if ssh_options?
      args << " -t"
      "ssh #{args}"
    end

Private methods

ssh delegates to these.

 
    module Ssh

      extend self

Ssh.simulate

Internal: Prints SSH command. Called by ssh.

 
      def simulate(cmd, ssh_command)
        str = "Executing the following via '#{ssh_command}':"
        puts "#!/usr/bin/env bash"
        puts "# #{str}"
        puts "#"

        puts cmd

        0
      end

Ssh.invoke

Internal: Initiates an SSH session with script script with given term_mode. Called by ssh.

 
      def invoke(script, this)
        term_mode = :"#{this.settings.term_mode}"
        code = "#{this.ssh_command} -- #{script}"

Certain environments can't do :pretty mode.

 
        term_mode = :exec  if term_mode == :pretty && !pretty_supported?

        case term_mode
        when :pretty
          this.pretty_system(code)
        when :exec
          exec code
        else
          system code
          $?.to_i
        end
      end

      def pretty_supported?

open4 is not supported under Windows. https://github.com/nadarei/mina/issues/58

 
        require 'rbconfig'
        ! (RbConfig::CONFIG['host_os'] =~ /mswin|mingw/)
      end

Ssh.ensure_successful

Internal: Halts the execution if the given result code is not successful (non-zero).

 
      def ensure_successful(result, this)
        this.die result if result.is_a?(Fixnum) && result > 0
        result
      end

    end

  end
end