Module: Fluent::Mixin::ConfigPlaceholders

Defined in:
lib/fluent/mixin/config_placeholders.rb

Constant Summary collapse

PLACEHOLDERS_DEFAULT =

and :percent

[ :dollar, :underscore ]

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#hostname ⇒ Object

Returns the value of attribute hostname.



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# File 'lib/fluent/mixin/config_placeholders.rb', line 7

def hostname
  @hostname
end

Instance Method Details

#configure(conf) ⇒ Object 



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# File 'lib/fluent/mixin/config_placeholders.rb', line 50

def configure(conf)
  # Element#has_key? inserts key name into 'used' list, so we should not use that method...
  hostname = if conf.keys.include?('hostname') && has_replace_pattern?( conf.fetch('hostname') )
               Socket.gethostname
             elsif conf.keys.include?('hostname')
               conf['hostname']
             else
               Socket.gethostname
             end

  placeholders = self.respond_to?(:placeholders) ? self.placeholders : PLACEHOLDERS_DEFAULT

  mapping = {}

  placeholders.each do |p|
    case p
    when :dollar
      mapping.update({
          '${hostname}'       => lambda{ hostname },
          '${uuid}'           => lambda{ uuid_random() },
          '${uuid:random}'    => lambda{ uuid_random() },
          '${uuid:hostname}'  => lambda{ uuid_hostname(hostname) },
          '${uuid:timestamp}' => lambda{ uuid_timestamp() },
        })
    when :percent
      mapping.update({
          '%{hostname}'       => lambda{ hostname },
          '%{uuid}'           => lambda{ uuid_random() },
          '%{uuid:random}'    => lambda{ uuid_random() },
          '%{uuid:hostname}'  => lambda{ uuid_hostname(hostname) },
          '%{uuid:timestamp}' => lambda{ uuid_timestamp() },
        })
    when :underscore
      mapping.update({
          '__HOSTNAME__'       => lambda{ hostname },
          '__UUID__'           => lambda{ uuid_random() },
          '__UUID_RANDOM__'    => lambda{ uuid_random() },
          '__UUID_HOSTNAME__'  => lambda{ uuid_hostname(hostname) },
          '__UUID_TIMESTAMP__' => lambda{ uuid_timestamp() },
        })
    else
      raise ArgumentError, "unknown placeholder format: #{p}"
    end
  end

  check_element = ->(map, c) {
    c.arg = replace(map, c.arg)
    c.keys.each do |k|
      v = c.fetch(k, nil)
      if v and v.is_a? String
        c[k] = replace(map, v)
      end
    end
    c.elements.each{|e| check_element.call(map,e)}
  }
  check_element.call(mapping,conf)

  super
end

#has_replace_pattern?(value) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/fluent/mixin/config_placeholders.rb', line 44

def has_replace_pattern?(value)
  value =~ /\$\{(?:hostname|uuid:[a-z]+)\}/ ||
    value =~ /\%\{(?:hostname|uuid:[a-z]+)\}/ ||
    value =~ /__(?:HOSTNAME|UUID_[A-Z]+)__/
end

#replace(map, value) ⇒ Object 



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# File 'lib/fluent/mixin/config_placeholders.rb', line 40

def replace(map, value)
  map.reduce(value){|r,p| r.gsub(p[0], p[1].call())}
end

#uuid_hostname(hostname) ⇒ Object 



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# File 'lib/fluent/mixin/config_placeholders.rb', line 30

def uuid_hostname(hostname)
  require 'uuidtools'
  UUIDTools::UUID.sha1_create(UUIDTools::UUID_DNS_NAMESPACE, hostname).to_s
end

#uuid_random ⇒ Object

$uuid:timestamp , %uuid:timestamp , UUID_TIMESTAMP UUIDTools::UUID.timestamp_create

> #<UUID:0x2adfdc UUID:64a5189c-25b3-11da-a97b-00c04fd430c8>



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# File 'lib/fluent/mixin/config_placeholders.rb', line 25

def uuid_random
  require 'uuidtools'
  UUIDTools::UUID.random_create.to_s
end

#uuid_timestamp ⇒ Object 



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# File 'lib/fluent/mixin/config_placeholders.rb', line 35

def uuid_timestamp
  require 'uuidtools'
  UUIDTools::UUID.timestamp_create.to_s
end