e.g Delete Logstash logs after 45 days
appender.rolling.strategy.type = DefaultRolloverStrategy
appender.rolling.strategy.action.type = Delete
appender.rolling.strategy.action.basepath = ${sys:ls.logs}
appender.rolling.strategy.action.condition.type = IfFileName
appender.rolling.strategy.action.condition.glob = logstash-${sys:ls.log.format}-*
appender.rolling.strategy.action.condition.nested_condition.type = IfLastModified
appender.rolling.strategy.action.condition.nested_condition.age = 45D