Module: DriverExecHelper

Included in:
OpenNebulaDriver
Defined in:
lib/DriverExecHelper.rb

Overview

This module provides an abstraction to generate an execution context for OpenNebula Drivers. The module has been designed to be included as part of a driver and not to be used standalone.

Constant Summary collapse

RESULT =

Action result strings for messages

{
    :success => 'SUCCESS',
    :failure => 'FAILURE'
}

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.failed?(rc_str) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/DriverExecHelper.rb', line 29

def self.failed?(rc_str)
    rc_str == RESULT[:failure]
end

Instance Method Details

#action_command_line(action, parameters, default_name = nil, directory = '') ⇒ String

METHODS FOR COMMAND LINE & ACTION PATHS

Given the action name and the parameter returns full path of the script and appends its parameters. It uses @local_actions hash to know if the actions is remote or local. If the local actions has defined an special script name this is used, otherwise the action name in downcase is used as the script name. When action is a String starting with ‘/’ it’s considered alreay full path command and no modification is performed apart from adding params.

Parameters:

  • action (String, Symbol) —

    name of the action

  • parameters (String) —

    arguments for the script

  • default_name (String, nil) (defaults to: nil) —

    alternative name for the script

  • directory (String, '') (defaults to: '') —

    to append to the scripts path for actions

Returns:

  • (String) —

    command line needed to execute the action



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# File 'lib/DriverExecHelper.rb', line 71

def action_command_line(action, parameters,
                        default_name = nil, directory = '')

    if action.is_a?(String) && action[0] == '/'
        return action + ' ' + parameters if parameters

        return action
    elsif action_is_local?(action, directory)
        script_path=File.join(@local_scripts_path, directory)
    else
        script_path=File.join(@remote_scripts_path, directory)
    end

    File.join(script_path, action_script_name(action, default_name))+
        ' '+parameters
end

#action_is_local?(action, driver = '') ⇒ Boolean

True if the action is meant to be executed locally

Parameters:

  • action (String, Symbol) —

    name of the action

  • driver (String, Symbol) (defaults to: '') —

    name

Returns:

  • (Boolean) 


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# File 'lib/DriverExecHelper.rb', line 92

def action_is_local?(action, driver = '')
    @local_actions.include? action.to_s.upcase if driver.empty?

    @local_actions.include? action.to_s.upcase or
        @per_drvr_local_actions.include? "#{driver}-#{action}"
end

#action_script_name(action, default_name = nil) ⇒ Object

Name of the script file for the given action

Parameters:

  • action (String, Symbol) —

    name of the action

  • default_name (String, nil) (defaults to: nil) —

    alternative name for the script



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# File 'lib/DriverExecHelper.rb', line 103

def action_script_name(action, default_name = nil)
    name=@local_actions[action.to_s.upcase]

    name || default_name || action.to_s.downcase
end

#get_info_from_execution(command_exe) ⇒ Object

This method returns the result in terms



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# File 'lib/DriverExecHelper.rb', line 158

def get_info_from_execution(command_exe)
    if command_exe.code == 0
        result = RESULT[:success]
        info   = command_exe.stdout
    else
        result = RESULT[:failure]
        info   = command_exe.get_error_message
    end

    info = '-' if info.nil? || info.empty?

    [result, info]
end

#initialize_helper(directory, options) ⇒ Object

Initialize module variables



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# File 'lib/DriverExecHelper.rb', line 34

def initialize_helper(directory, options)
    @config = read_configuration
    @remote_scripts_base_path = @config['SCRIPTS_REMOTE_DIR']

    @local_actions = options[:local_actions]
    @per_drvr_local_actions = options[:per_drvr_local_actions] || []

    if ENV['ONE_LOCATION'].nil?
        @local_scripts_base_path = '/var/lib/one/remotes'
    else
        @local_scripts_base_path = "#{ENV['ONE_LOCATION']}/var/remotes"
    end

    # dummy paths
    @remote_scripts_path = File.join(@remote_scripts_base_path, directory)
    @local_scripts_path  = File.join(@local_scripts_base_path, directory)

    # mutex for logging
    @send_mutex = Mutex.new
end

#log(number, message, all = true) ⇒ Object

Sends a log message to ONE. The message can be multiline, it will be automatically splitted by lines.



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# File 'lib/DriverExecHelper.rb', line 126

def log(number, message, all = true)
    msg = message.strip

    msg.each_line do |line|
        all ? severity='I' : severity=nil

        if line.match(/^(ERROR|DEBUG|INFO):(.*)$/)
            line=Regexp.last_match(2)

            case Regexp.last_match(1)
            when 'ERROR'
                severity='E'
            when 'DEBUG'
                severity='D'
            when 'INFO'
                severity='I'
            end
        end

        send_message('LOG', severity, number, line.strip) if severity
    end
end

#log_method(num) ⇒ Object

Generates a proc with that calls log with a hardcoded number. It will be used to add loging to command actions



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# File 'lib/DriverExecHelper.rb', line 151

def log_method(num)
    lambda {|message, all = true|
        log(num, message, all)
    }
end

#read_configuration ⇒ Object

Simple parser for the config file generated by OpenNebula



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# File 'lib/DriverExecHelper.rb', line 175

def read_configuration
    one_config=nil

    if ENV['ONE_LOCATION']
        one_config = ENV['ONE_LOCATION']+'/var/config'
    else
        one_config = '/var/lib/one/config'
    end

    config = {}
    cfg    = ''

    begin
        File.open(one_config, 'r') do |file|
            cfg=file.read
        end

        cfg.split(/\n/).each do |line|
            m=line.match(/^([^=]+)=(.*)$/)

            next unless m

            name  = m[1].strip.upcase
            value = m[2].strip

            if config[name]
                if config[name].instance_of? Array
                    config[name] << value
                else
                    config[name] = [config[name], value]
                end
            else
                config[name]=value
            end
        end
    rescue StandardException => e
        STDERR.puts "Error reading config: #{e.inspect}"
        STDERR.flush
    end

    config
end

#send_message(action = '-', result = , id = '-', info = '-') ⇒ Object

METHODS FOR LOGS & COMMAND OUTPUT

Sends a message to the OpenNebula core through stdout rubocop:disable Metrics/ParameterLists



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# File 'lib/DriverExecHelper.rb', line 114

def send_message(action = '-', result = RESULT[:failure],
                 id = '-', info = '-')

    @send_mutex.synchronize do
        STDOUT.puts "#{action} #{result} #{id} #{info}"
        STDOUT.flush
    end
end