Class: LogStash::Inputs::Multirds

Inherits:
Base
  • Object
show all
Includes:
PluginMixins::AwsConfig::V2
Defined in:
lib/logstash/inputs/multirds.rb

Instance Method Summary collapse

Instance Method Details

#acquire_lock(db, table, id, lock_owner, expire_time) ⇒ Object 



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# File 'lib/logstash/inputs/multirds.rb', line 65

def acquire_lock(db, table, id, lock_owner, expire_time)
  begin
    db.update_item(
      key: {
        id: id
      },
      table_name: table,
      update_expression: 'SET lock_owner = :lock_owner, expires = :expires',
      expression_attribute_values: {
        ':lock_owner' => lock_owner,
        ':expires' => Time.now.utc.to_i + expire_time
      },
      return_values: 'UPDATED_NEW',
      # condition_expression: 'attribute_not_exists(lock_owner) OR lock_owner = :lock_owner OR expires < :expires'
      condition_expression: 'attribute_not_exists(lock_owner) OR expires < :expires'
    )
  # TODO: handle condition exception else throw error
  rescue Aws::DynamoDB::Errors::ConditionalCheckFailedException
    return false
  rescue StandardError => e
    @logger.error "logstash-input-multirds acquire_lock exception\n #{e}"
    false
  end
  true
end

#ensure_lock_table(db, table) ⇒ Object 



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# File 'lib/logstash/inputs/multirds.rb', line 24

def ensure_lock_table(db, table)
  begin
    tables = db.list_tables({

                            })
    return true if tables.to_h[:table_names].to_a.include?(table)
    # TODO: there is a potential race condition here where a table could come back in list_tables but not be in ACTIVE state we should check this better
    db.create_table(
      table_name: table,
      key_schema: [
        {
          attribute_name: 'id',
          key_type: 'HASH'
        }
      ],
      attribute_definitions: [
        {
          attribute_name: 'id',
          attribute_type: 'S'
        }
      ],
      provisioned_throughput: {
        read_capacity_units: 10,
        write_capacity_units: 10
      }
    )

    # wait here for the table to be ready
    (1..10).each do |i|
      sleep i
      rsp = db.describe_table(
        table_name: table
      )
      return true if rsp.to_h[:table][:table_status] == 'ACTIVE'
    end
  rescue StandardError => e
    @logger.error "logstash-input-multirds ensure_lock_table exception\n #{e}"
    return false
  end
  false
end

#get_logfile_list(rds, instance_pattern, logfile_pattern) ⇒ Object 



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# File 'lib/logstash/inputs/multirds.rb', line 91

def get_logfile_list(rds, instance_pattern, logfile_pattern)
  log_files = []
  begin
    dbs = rds.describe_db_instances
    dbs.to_h[:db_instances].each do |db|
      next unless db[:db_instance_identifier] =~ /#{instance_pattern}/
      logs = rds.describe_db_log_files(
        db_instance_identifier: db[:db_instance_identifier]
      )

      logs.to_h[:describe_db_log_files].each do |log|
        next unless log[:log_file_name] =~ /#{logfile_pattern}/
        log[:db_instance_identifier] = db[:db_instance_identifier]
        log_files.push(log)
      end
    end
  rescue StandardError => e
    @logger.error "logstash-input-multirds get_logfile_list instance_pattern: #{instance_pattern} logfile_pattern:#{logfile_pattern} exception \n#{e}"
  end
  log_files
end

#get_logfile_record(db, id, tablename) ⇒ Object 



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# File 'lib/logstash/inputs/multirds.rb', line 113

def get_logfile_record(db, id, tablename)
  out = {}
  begin
    res = db.get_item(
      key: {
        id: id
      },
      table_name: tablename
    )
    extra_fields = { 'marker' => '0:0' }
    out = extra_fields.merge(res.item)
  rescue StandardError => e
    @logger.error "logstash-input-multirds get_logfile_record  exception \n#{e}"
  end
  out
end

#register ⇒ Object 



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# File 'lib/logstash/inputs/multirds.rb', line 149

def register
  @client_id ||= "#{Socket.gethostname}:#{java.util::UUID.randomUUID}"
  @logger.info 'Registering multi-rds input', instance_name_pattern: @instance_name_pattern, log_file_name_pattern: @log_file_name_pattern, group_name: @group_name, region: @region, client_id: @client_id

  @db = Aws::DynamoDB::Client.new aws_options_hash
  @rds = Aws::RDS::Client.new aws_options_hash

  @ready = ensure_lock_table @db, @group_name
end

#run(queue) ⇒ Object 



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# File 'lib/logstash/inputs/multirds.rb', line 159

def run(queue)
  unless @ready
    @logger.warn 'multi-rds dynamodb lock table not ready, unable to proceed'
    return false
  end
  @thread = Thread.current
  Stud.interval(@polling_frequency) do
    logs = get_logfile_list @rds, @instance_name_pattern, @log_file_name_pattern

    logs.each do |log|
      id = "#{log[:db_instance_identifier]}:#{log[:log_file_name]}"
      lock = acquire_lock @db, @group_name, id, @client_id, (@polling_frequency - 1)
      next unless lock # we won't do anything with the data unless we get a lock on the file

      rec = get_logfile_record @db, id, @group_name
      next unless rec['marker'].split(':')[1].to_i < log[:size].to_i # No new data in the log file so just continue

      # start reading log data at the marker
      more = true
      marker = rec[:marker]
      while more
        rsp = @rds.download_db_log_file_portion(
          db_instance_identifier: log[:db_instance_identifier],
          log_file_name: log[:log_file_name],
          marker: marker
        )
        rsp[:log_file_data].lines.each do |line|
          @codec.decode(line) do |event|
            decorate event
            event.set 'rds_instance', log[:db_instance_identifier]
            event.set 'log_file', log[:log_file_name]
            queue << event
          end
        end
        more = rsp[:additional_data_pending]
        marker = rsp[:marker]
      end
      # set the marker back in the lock table
      set_logfile_record @db, id, @group_name, 'marker', marker
    end
  end
end

#set_logfile_record(db, id, tablename, key, value) ⇒ Object 



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# File 'lib/logstash/inputs/multirds.rb', line 130

def set_logfile_record(db, id, tablename, key, value)
  begin
  out = db.update_item(
      key: {
        id: id
      },
      table_name: tablename,
      update_expression: "SET #{key} = :v",
      expression_attribute_values: {
        ':v' => value
      },
      return_values: 'UPDATED_NEW'
    )
  rescue StandardError => e
    @logger.error "logstash-input-multirds set_logfile_record  exception \n#{e}"
  end
  out
end

#stop ⇒ Object 



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# File 'lib/logstash/inputs/multirds.rb', line 202

def stop
  Stud.stop! @thread
end