Class: Fluent::Plugin::WindowsEventLog2Input

Inherits:
Input
  • Object
show all
Defined in:
lib/fluent/plugin/in_windows_eventlog2.rb

Defined Under Namespace

Classes: ReconnectError

Constant Summary collapse

DEFAULT_STORAGE_TYPE = 
'local'
KEY_MAP = 
{"ProviderName"      => ["ProviderName",          :string],
"ProviderGUID"      => ["ProviderGUID",          :string],
"EventID"           => ["EventID",               :string],
"Qualifiers"        => ["Qualifiers",            :string],
"Level"             => ["Level",                 :string],
"Task"              => ["Task",                  :string],
"Opcode"            => ["Opcode",                :string],
"Keywords"          => ["Keywords",              :string],
"TimeCreated"       => ["TimeCreated",           :string],
"EventRecordID"     => ["EventRecordID",         :string],
"ActivityID"        => ["ActivityID",            :string],
"RelatedActivityID" => ["RelatedActivityID",     :string],
"ProcessID"         => ["ProcessID",             :string],
"ThreadID"          => ["ThreadID",              :string],
"Channel"           => ["Channel",               :string],
"Computer"          => ["Computer",              :string],
"UserID"            => ["UserID",                :string],
"Version"           => ["Version",               :string],
"Description"       => ["Description",           :string],
"EventData"         => ["EventData",             :array]}
GROUP_DELIMITER =

These lines copied from in_windows_eventlog plugin: github.com/fluent/fluent-plugin-windows-eventlog/blob/528290d896a885c7721f850943daa3a43a015f3d/lib/fluent/plugin/in_windows_eventlog.rb#L192-L232

"\r\n\r\n".freeze
RECORD_DELIMITER = 
"\r\n\t".freeze
FIELD_DELIMITER = 
"\t\t".freeze
NONE_FIELD_DELIMITER = 
"\t".freeze

Instance Method Summary collapse

Instance Method Details

#bookmark_validator(bookmarkXml, channel) ⇒ Object 



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# File 'lib/fluent/plugin/in_windows_eventlog2.rb', line 257

def bookmark_validator(bookmarkXml, channel)
  return false if bookmarkXml.empty?

  evtxml = WinevtBookmarkDocument.new
  parser = Nokogiri::XML::SAX::Parser.new(evtxml)
  parser.parse(bookmarkXml)
  result = evtxml.result
  if !result.empty? && (result[:channel].downcase == channel.downcase) && result[:is_current]
    true
  else
    log.warn "This stored bookmark is incomplete for using. Referring `read_existing_events` parameter to subscribe: #{bookmarkXml}, channel: #{channel}"
    false
  end
end

#clear_subscritpions ⇒ Object 



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# File 'lib/fluent/plugin/in_windows_eventlog2.rb', line 205

def clear_subscritpions
  @subscriptions.keys.each do |ch|
    subscription = @subscriptions.delete(ch)
    if subscription
      if subscription.cancel
        log.debug "channel (#{ch}) subscription is cancelled."
        subscription.close
        log.debug "channel (#{ch}) subscription handles are closed forcibly."
      end
    end
  end
  @timers.keys.each do |ch|
    timer = @timers.delete(ch)
    if timer
      event_loop_detach(timer)
      log.debug "channel (#{ch}) subscription watcher is detached."
    end
  end
end

#configure(conf) ⇒ Object 



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# File 'lib/fluent/plugin/in_windows_eventlog2.rb', line 77

def configure(conf)
  super
  @session = nil
  @chs = []
  @subscriptions = {}
  @all_chs = Winevt::EventLog::Channel.new
  @all_chs.force_enumerate = false
  @timers = {}

  if @read_all_channels
    @all_chs.each do |ch|
      uch = ch.strip.downcase
      @chs.push([uch, @read_existing_events])
    end
  end

  @read_existing_events = @read_from_head || @read_existing_events
  if @channels.empty? && @subscribe_configs.empty? && !@read_all_channels
    @chs.push(['application', @read_existing_events, nil])
  else
    @channels.map {|ch| ch.strip.downcase }.uniq.each do |uch|
      @chs.push([uch, @read_existing_events, nil])
    end
    @subscribe_configs.each do |subscribe|
      if subscribe.remote_server
        @session = Winevt::EventLog::Session.new(subscribe.remote_server,
                                                 subscribe.remote_domain,
                                                 subscribe.remote_username,
                                                 subscribe.remote_password)

        log.debug("connect to remote box (server: #{subscribe.remote_server}) domain: #{subscribe.remote_domain} username: #{subscribe.remote_username})")
      end
      subscribe.channels.map {|ch| ch.strip.downcase }.uniq.each do |uch|
        @chs.push([uch, subscribe.read_existing_events, @session])
      end
    end
  end
  @chs.uniq!
  @keynames = @keys.map {|k| k.strip }.uniq
  if @keynames.empty?
    @keynames = KEY_MAP.keys
  end

  @tag = tag
  @bookmarks_storage = storage_create(usage: "bookmarks")
  @winevt_xml = false
  @parser = nil
  if @render_as_xml
    @parser = parser_create
    @winevt_xml = @parser.respond_to?(:winevt_xml?) && @parser.winevt_xml?
    class << self
      alias_method :on_notify, :on_notify_xml
    end
  else
    class << self
      alias_method :on_notify, :on_notify_hash
    end
  end

  if @render_as_xml && @preserve_qualifiers_on_hash
    raise Fluent::ConfigError, "preserve_qualifiers_on_hash must be used with Hash object rendering(render_as_xml as false)."
  end
  if !@render_as_xml && !@preserve_qualifiers_on_hash
    @keynames.delete('Qualifiers')
  elsif @parser.respond_to?(:preserve_qualifiers?) && !@parser.preserve_qualifiers?
    @keynames.delete('Qualifiers')
  end
  @keynames.delete('EventData') if @parse_description

  locale = Winevt::EventLog::Locale.new
  if @description_locale && unsupported_locale?(locale, @description_locale)
    raise Fluent::ConfigError, "'#{@description_locale}' is not supported. Supported locales are: #{locale.each.map{|code, _desc| code}.join(" ")}"
  end
end

#escape_channel(ch) ⇒ Object 



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# File 'lib/fluent/plugin/in_windows_eventlog2.rb', line 272

def escape_channel(ch)
  ch.gsub(/[^a-zA-Z0-9\s]/, '_')
end

#initalize ⇒ Object 



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# File 'lib/fluent/plugin/in_windows_eventlog2.rb', line 71

def initalize
  super
  @chs = []
  @keynames = []
end

#on_notify(ch, subscribe) ⇒ Object 



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# File 'lib/fluent/plugin/in_windows_eventlog2.rb', line 276

def on_notify(ch, subscribe)
  # for safety.

end

#on_notify_hash(ch, subscribe) ⇒ Object 



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# File 'lib/fluent/plugin/in_windows_eventlog2.rb', line 322

def on_notify_hash(ch, subscribe)
  es = Fluent::MultiEventStream.new
  begin
    subscribe.each do |record, message, string_inserts|
      record["Description"] = message
      record["EventData"] = string_inserts
      h = {}
      @keynames.each do |k|
        type = KEY_MAP[k][1]
        value = record[KEY_MAP[k][0]]
        h[k]=case type
             when :string
               value.to_s
             when :array
               value.map {|v| v.to_s}
             else
               raise "Unknown value type: #{type}"
             end
      end
      parse_desc(h) if @parse_description
      es.add(Fluent::Engine.now, h)
    end
    router.emit_stream(@tag, es)
    @bookmarks_storage.put(ch, subscribe.bookmark)
    log.trace "Collecting Windows EventLog from #{ch} channel. Collected size: #{es.size}"
  rescue Winevt::EventLog::Query::Error => e
    log.warn "Invalid Hash data on #{ch}.", error: e
    log.warn_backtrace
  end
end

#on_notify_xml(ch, subscribe) ⇒ Object 



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# File 'lib/fluent/plugin/in_windows_eventlog2.rb', line 280

def on_notify_xml(ch, subscribe)
  es = Fluent::MultiEventStream.new
  begin
    subscribe.each do |xml, message, string_inserts|
      @parser.parse(xml) do |time, record|
        # record.has_key?("EventData") for none parser checking.

        if @winevt_xml
          record["Description"] = message
          record["EventData"] = string_inserts

          h = {}
          @keynames.each do |k|
            type = KEY_MAP[k][1]
            value = record[KEY_MAP[k][0]]
            h[k]=case type
                 when :string
                   value.to_s
                 when :array
                   value.map {|v| v.to_s}
                 else
                   raise "Unknown value type: #{type}"
                 end
          end
          parse_desc(h) if @parse_description
          es.add(Fluent::Engine.now, h)
        else
          record["Description"] = message
          record["EventData"] = string_inserts
          # for none parser

          es.add(Fluent::Engine.now, record)
        end
      end
    end
    router.emit_stream(@tag, es)
    @bookmarks_storage.put(ch, subscribe.bookmark)
    log.trace "Collecting Windows EventLog from #{ch} channel. Collected size: #{es.size}"
  rescue Winevt::EventLog::Query::Error => e
    log.warn "Invalid XML data on #{ch}.", error: e
    log.warn_backtrace
  end
end

#parse_desc(record) ⇒ Object 



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# File 'lib/fluent/plugin/in_windows_eventlog2.rb', line 360

def parse_desc(record)
  desc = record.delete("Description".freeze)
  return if desc.nil?

  elems = desc.split(GROUP_DELIMITER)
  record['DescriptionTitle'] = elems.shift
  previous_key = nil
  elems.each { |elem|
    parent_key = nil
    elem.split(RECORD_DELIMITER).each { |r|
      key, value = if r.index(FIELD_DELIMITER)
                     r.split(FIELD_DELIMITER)
                   else
                     r.split(NONE_FIELD_DELIMITER)
                   end
      key = "" if key.nil?
      key.chop!  # remove ':' from key

      if value.nil?
        parent_key = to_key(key)
      else
        # parsed value sometimes contain unexpected "\t". So remove it.

        value.strip!
        # merge empty key values into the previous non-empty key record.

        if key.empty?
          record[previous_key] = [record[previous_key], value].flatten.reject {|e| e.nil?}
        elsif parent_key.nil?
          record[to_key(key)] = value
        else
          k = "#{parent_key}.#{to_key(key)}"
          record[k] = value
        end
      end
      # XXX: This is for empty privileges record key.

      # We should investigate whether an another case exists or not.

      previous_key = to_key(key) unless key.empty?
    }
  }
end

#refresh_subscriptions ⇒ Object 



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# File 'lib/fluent/plugin/in_windows_eventlog2.rb', line 193

def refresh_subscriptions
  clear_subscritpions

  @chs.each do |ch, read_existing_events, session|
    retry_on_error(ch) do
      ch, subscribe = subscription(ch, read_existing_events, session)
      @subscriptions[ch] = subscribe
    end
  end
  subscribe_channels(@subscriptions)
end

#retry_on_error(channel, times: 15) ⇒ Object 



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# File 'lib/fluent/plugin/in_windows_eventlog2.rb', line 177

def retry_on_error(channel, times: 15)
  try = 0
  begin
    log.debug "Retry to subscribe for #{channel}...." if try > 1
    try += 1
    yield
    log.info "Retry to subscribe for #{channel} succeeded." if try > 1
    try = 0
  rescue Winevt::EventLog::Subscribe::RemoteHandlerError => e
    raise ReconnectError, "Retrying limit is exceeded." if try > times
    log.warn "#{e.message}. Remaining retry count(s): #{times - try}"
    sleep 2**try
    retry
  end
end

#shutdown ⇒ Object 



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# File 'lib/fluent/plugin/in_windows_eventlog2.rb', line 165

def shutdown
  super

  @subscriptions.keys.each do |ch|
    subscription = @subscriptions.delete(ch)
    if subscription
      subscription.cancel
      log.debug "channel (#{ch}) subscription is canceled."
    end
  end
end

#start ⇒ Object 



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# File 'lib/fluent/plugin/in_windows_eventlog2.rb', line 156

def start
  super

  refresh_subscriptions
  if @refresh_subscription_interval
    timer_execute(:in_windows_eventlog_refresh_subscription_timer, @refresh_subscription_interval, &method(:refresh_subscriptions))
  end
end

#subscribe_channels(subscriptions) ⇒ Object 



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# File 'lib/fluent/plugin/in_windows_eventlog2.rb', line 247

def subscribe_channels(subscriptions)
  subscriptions.each do |ch, subscribe|
    log.trace "Subscribing Windows EventLog at #{ch} channel"
    @timers[ch] = timer_execute("in_windows_eventlog_#{escape_channel(ch)}".to_sym, @read_interval) do
      on_notify(ch, subscribe)
    end
    log.debug "channel (#{ch}) subscription is subscribed."
  end
end

#subscription(ch, read_existing_events, remote_session) ⇒ Object 



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# File 'lib/fluent/plugin/in_windows_eventlog2.rb', line 225

def subscription(ch, read_existing_events, remote_session)
  bookmarkXml = @bookmarks_storage.get(ch) || ""
  bookmark = nil
  if bookmark_validator(bookmarkXml, ch)
    bookmark = Winevt::EventLog::Bookmark.new(bookmarkXml)
  end
  subscribe = Winevt::EventLog::Subscribe.new
  subscribe.read_existing_events = read_existing_events
  begin
    subscribe.subscribe(ch, event_query, bookmark, remote_session)
    if !@render_as_xml && @preserve_qualifiers_on_hash
      subscribe.preserve_qualifiers = @preserve_qualifiers_on_hash
    end
  rescue Winevt::EventLog::Query::Error => e
    raise Fluent::ConfigError, "Invalid Bookmark XML is loaded. #{e}"
  end
  subscribe.render_as_xml = @render_as_xml
  subscribe.rate_limit = @rate_limit
  subscribe.locale = @description_locale if @description_locale
  [ch, subscribe]
end

#to_key(key) ⇒ Object 



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# File 'lib/fluent/plugin/in_windows_eventlog2.rb', line 399

def to_key(key)
  key.downcase!
  key.gsub!(' '.freeze, '_'.freeze)
  key
end

#unsupported_locale?(locale, description_locale) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/fluent/plugin/in_windows_eventlog2.rb', line 152

def unsupported_locale?(locale, description_locale)
  locale.each.select {|c, _d| c.downcase == description_locale.downcase}.empty?
end