ClusterLabs/hawk

# Copyright (c) 2009-2015 Tim Serong <tserong@suse.com>
# See COPYING for license.

require 'singleton'
require 'thread'

class NotFoundError < RuntimeError
end

#
# Singleton class for invoking crm configuration tools as the current
# user, obtained by trickery from ApplicationController, which injects
# a "current_user" method into this class.
#
class Invoker
  include Singleton
  include FastGettext::Translation
  include Util

  def initialize
    @mutex = Mutex.new
  end

  # Invoke some command, returning true or [exitstatus, message]
  # as appropriate (refactored somewhat from MainController::invoke,
  # and suspiciously similar to invoke_crm - obviously this can be
  # cleaned up further)
  # Returns [out, err, exitstatus]
  def run(*cmd)
    out, err, status = Util.run_as(current_user, current_pass, *cmd)
    [out, fudge_error(status.exitstatus, err), status.exitstatus]
  end

  def no_log
    @mutex.synchronize {
      begin
        @no_log = true
        yield self
      ensure
        @no_log = false
      end
    }
  end

  # Run "crm [...]"
  # Returns [out, err, exitstatus]
  def crm(*cmd)
    invoke_crm nil, *cmd
  end

  # Run "crm configure", passing input via STDIN.
  # Returns [out, err, exitstatus]
  def crm_configure(input)
    invoke_crm input, "configure"
  end

  # Run "crm -F configure load update"
  # Returns [out, err, exitstatus]
  def crm_configure_load_update(cmd)
    require 'tempfile.rb'
    f = Tempfile.new 'crm_config_update'
    begin
      f << cmd
      f.close
      CrmEvents.instance.push "crm configure\n#{cmd}\n" unless @no_log
      result = crm '-F', 'configure', 'load', 'update', f.path
    ensure
      f.unlink
    end
    result
  end

  # Invoke cibadmin with command line arguments.  Returns stdout as string,
  # Raises NotFoundError, SecurityError or RuntimeError on failure.
  def cibadmin(*cmd)
    out, err, status = Util.run_as(current_user, current_pass, 'cibadmin', *cmd)
    case status.exitstatus
    when 0
      return out
    when 6, 22 # cib_NOTEXISTS (used to be 22, now it's 6...)
      fail(NotFoundError, _('The object/attribute does not exist (cibadmin %{cmd})') % { cmd: cmd.join(" ") })
    when 13, 54 # cib_permission_denied (used to be 54, now it's 13...)
      fail(SecurityError, _('Permission denied for user %{user}') % { user: current_user })
    else
      fail(_('Error invoking cibadmin %{cmd}: %{msg}') % { cmd: cmd.join(" "), msg: err })
    end
    # Never reached
  end

  # Invoke "cibadmin -p --replace"
  def cibadmin_replace(xml)
    CrmEvents.instance.push "cibadmin -p --replace <<EOF\n#{xml}\nEOF" unless @no_log
    cibadmin '-p', '--replace', stdin_data: xml
  end

  def cibadmin_replace_xpath(xpath, xml)
    CrmEvents.instance.push "cibadmin -p --replace --xpath #{xpath} <<EOF\n#{xml}\nEOF" unless @no_log
    cibadmin '-p', '--replace', '--xpath', xpath, stdin_data: xml
  end

  def cibadmin_modify(xml)
    CrmEvents.instance.push "cibadmin -p -c --modify <<EOF\n#{xml}\nEOF" unless @no_log
    cibadmin '-p', '-c', '--modify', stdin_data: xml
  end

  # Used by the simulator
  def crm_simulate(*cmd)
    Util.run_as(current_user, current_pass, 'crm_simulate', *cmd)
  end

  private

  def ignore_command(input, cmd)
    return true if cmd[0] == 'cluster'
    if cmd[0] == 'configure'
      return true if input == 'show'
      return true if cmd[1] == 'graph'
    end
    return true if cmd[0..3] == ['-F', 'configure', 'load', 'update']
    false
  end

  # Returns [out, err, exitstatus]
  def invoke_crm(input, *cmd)
    # don't log certain calls to crmevents
    unless @no_log || ignore_command(input, cmd)
      if input
        CrmEvents.instance.push "crm #{cmd.join(' ')}\n#{input}"
      else
        CrmEvents.instance.push "crm #{cmd.join(' ')}"
      end
    end
    cmd << { stdin_data: input }

    out, err, status = Util.run_as(current_user, current_pass, 'crm', *cmd)
    [out, fudge_error(status.exitstatus, err), status.exitstatus]
  end

  def fudge_error(exitstatus, stderr)
    if exitstatus == 0 && stderr.index("WARNING: Creating rsc_location constraint") && !stderr.index("ERROR")
      # Special case for "crm resource migrate" with no node specified, to squash
      # warning about persistent location constraint (remember my *sigh* in the
      # comment above?)
      stderr = ""
    elsif exitstatus != 0 || stderr.upcase.index("ERROR")
      if stderr.match(/-54.*permission denied/i) || stderr.match(/-13.*permission denied/i)
        stderr = _('Permission denied for user %{user}') % {:user => current_user}
      end
    end
    stderr
  end

  def current_user
    Thread.current[:current_user].call
  end

  def current_pass
    Thread.current[:current_pass].call
  end
end