Module: Configuration

Included in:
Apprentice::Sentinel
Defined in:
lib/apprentice/configuration.rb

Overview

This module contains all the command line configuration methods

Instance Method Summary collapse

Instance Method Details

#check_type(type) ⇒ Object

Check the user input for a valid type

Attributes

  • type - the type extracted from ARGV

Return values

Either true or false, depending on whether the input provided matches either ‘mysql’ or ‘galera’

Example

r = check_type('mysql')
r.inspect # => 'true'

r = check_type('something else')
r.inspect # => 'false'



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# File 'lib/apprentice/configuration.rb', line 125

def check_type(type)
  %w{galera mysql}.each do |t|
    return true if t == type
  end
  false
end

#get_config ⇒ Object

Reads ARGV with OptionParser and return an OpenStruct object with the parsed values

Default values

  • ip - By default Apprentice binds to 0.0.0.0.

  • port - The port Apprentice binds to. It defaults to 3307.

  • sql_port - The port the MariaDB/MySQL server listens on Apprentice connects to. Defaults to 3306.

  • threshold - The acceptable slave lag in seconds. Defaults to 120 seconds. It only applies when the type is set to ‘mysql’.

  • accept_donor - If passed, cluster members in the state ‘2’ aka “Donor/Desynced” are accepted as valid client providers. Defaults to false, which is recommended.

Attributes

  • ARGV

Return values

  • options - OpenStruct object containing all options passed with ARGV

Example

ARGV = "--user user --password password --server server"
opt = get_config
opt.user     # => 'user'
opt.password # => 'password'
opt.server   # => 'server'



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# File 'lib/apprentice/configuration.rb', line 32

def get_config
  options = OpenStruct.new
  options.ip = '0.0.0.0'
  options.port = 3307
  options.sql_port = 3306
  options.accept_donor = false
  options.threshold = 120

  opt_parser = OptionParser.new do |opts|
    opts.banner = "Usage: apprentice [options]\n"
    opts.separator ''
    opts.separator 'Specific options:'

    opts.on('-s SERVER', '--server SERVER',
      'SERVER to connect to') { |s| options.server = s }
    opts.on('-u USER', '--user USER',
      'USER to connect to the server with') { |u| options.user = u }
    opts.on('-p PASSWORD', '--password PASSWORD',
      'PASSWORD to use') { |p| options.password = p }
    opts.on('-t TYPE', '--type TYPE',
      'TYPE of server. Must either by "galera" or "mysql".') { |t| options.type = t }

    opts.on('-i', '--ip IP',
      'Local IP to bind to',
      "(default: #{options.ip})") { |i| options.ip = i }
    opts.on('--port PORT',
      'Local PORT to use',
      "(default: #{options.port})") { |p| options.port = p }
    opts.on('--sql_port PORT',
      'Port of MariaDB/MySQL server to connect to',
      "(default: #{options.sql_port})") { |p| options.sql_port = p }
    opts.on('--[no-]accept-donor',
      'Accept galera cluster state "Donor/Desynced" as valid',
      "(default: #{options.accept_donor})") { |ad| options.accept_donor = ad }
    opts.on('--threshold SECONDS',
      'MariaDB/MySQL slave lag threshold',
      "(default: #{options.threshold})") { |tr| options.threshold = tr }

    opts.separator ''
    opts.separator 'Common options:'

    opts.on_tail('-h', '--help', 'Show this message') do
      puts opts
      exit
    end
    opts.on_tail('-v', '--version', 'Show version') do
      puts "Apprentice #{Apprentice::VERSION}"
      exit
    end
  end

  begin
    opt_parser.parse!(ARGV)

    # We need four variables:
    # * user: a valid mysql user
    # * password: the corresponding password
    # * server: the server to connect to
    # * type: either mysql or galera, depending on the setup
    unless options.server &&
        options.user &&
        options.password &&
        check_type(options.type)
      $stderr.puts 'Error: you have to specify a user, a password, a server to connect to'
      $stderr.puts 'and a valid type. It can either by "galera" or "mysql".'
      $stderr.puts 'Try -h/--help for more options'
      exit
    end
    return options
  rescue OptionParser::ParseError
    $stderr.print "Error: #{$!}\n"
    exit
  end
end