Class: Nagios::Config

Inherits:
Object
  • Object
show all
Defined in:
lib/nagios/config.rb

Overview

Note:

If you have more than one /etc/nagios* directories then only

Parser of the main Nagios configuration file – nagios.cfg.

Constructor parses Nagios’ main config file and returns an object: each configuration option’s value assigned to an instance variable and attribute reader method is created.

Can be used as:

    require 'nagios/config'
    nagios = Nagios::Config.new "lib/ruby-nagios/test/data/nagios.cfg"

    nagios.log_file
=> "/var/log/nagios3/nagios.log"

    nagios.status_file
=> "/var/cache/nagios3/status.dat"

Configuration of the module

Default search directory and file pattern (Dir.glob) is defined by Nagios::DEFAULT constant. It is set in config/default.rb file.

first one will be used. For example, Debian can have both Nagios 2 and 3 installed. In the latter case configuration file is /etc/nagios3/nagios.cfg.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(config_file = nil) ⇒ Config

Initialize configuration file path. Check existence and readability of the file, raise exception if not.

Parameters:

  • config_file (String) (defaults to: nil) —

    PATH to the configuration file. If PATH is not provided method will look for configuration file nagios.cfg in directory, defined by Nagios::DEFAULT constant ( ususally /etc/nagios*/nagios.cfg);



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# File 'lib/nagios/config.rb', line 47

def initialize config_file=nil

  @config = config_file || Dir.glob( Nagios::DEFAULT[:nagios_cfg_glob] ).first
  @path = @config

  @configuration ||= {}
  raise "No configuration file option and no files in #{ DEFAULT[:nagios_cfg_glob] } " unless @config
  raise "Configuration file #{@config} does not exist" unless File.exist? @config
  raise "Configuration file #{@config} is not readable" unless File.readable? @config

end

Instance Attribute Details

#cfg_dir ⇒ Object (readonly)

Special case for cfg_file and cfg_dir: they are Arrays



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# File 'lib/nagios/config.rb', line 101

def cfg_dir
  @cfg_dir
end

#cfg_file ⇒ Object (readonly)

Special case for cfg_file and cfg_dir: they are Arrays



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# File 'lib/nagios/config.rb', line 101

def cfg_file
  @cfg_file
end

#configuration ⇒ Object

Hash holding all the configuration after parsing. Additionally for every key in the configuration Hash method is created with the same name, which returns the value.



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# File 'lib/nagios/config.rb', line 62

def configuration
  @configuration
end

#path ⇒ Object

Path to main configuration file nagios.cfg



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# File 'lib/nagios/config.rb', line 66

def path
  @path
end

Instance Method Details

#parse ⇒ Object

Read and parse main Nagios configuration file nagios.cfg

Author:



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# File 'lib/nagios/config.rb', line 73

def parse
  idx=0
  File.readlines(@config).map{ |l| l.sub(/\s*#.*$/,'')}.delete_if { |l| l=~ /^\s*$/}.each do |l|
    idx += 1
    key,val = l.chomp.strip.split(/\s*=\s*/,2)
    raise "Incorrect configuration line ##{idx}: '#{l}'" unless key && val

    case key
      # There could be multiple entries for cfg_dir/file, so these
      # are Arrays.
    when /cfg_(file|dir)/
      @configuration[key] ||= []
      @configuration[key] << val
      instance_variable_set("@#{key}", (instance_variable_get("@#{key}") || []) << val )
    else

      @configuration[key] = val
      instance_variable_set("@#{key}", val)
      instance_eval val =~ /^[\d\.-]+$/ ? 
      "def #{key}; return #{val}; end" :
        "def #{key}; return %Q{#{val}}; end"
    end
  end

  self
end