lua는 Lua스크립트를 실행해 다양한 작업을 처리한다.

다음은 타임스탬프를 추가하는 예제이다.

[SERVICE]
    Flush 1
    Daemon off

[INPUT]
    Name tail
    Tag my_tail
    path /var/log/logf/app.log

[FILTER]
    Name lua
    Match my_tail
    script script.lua
    call append_timestamp

[OUTPUT]
    Name stdout
    Match my_tail

function append_timestamp(tag, timestamp, record)
    new_record = record
    new_record["timestamp"] = timestamp
    return 1, timestamp, new_record
end

function format_timestamp(tag, timestamp, record)
        new_record = record
        print(new_record["timestamp"])
        new_record["timestamp"] = new_record["timestamp"]:gsub(",", ".")
        return 1, timestamp, new_record
end

function stringtonumber(tag, timestamp, record)
        new_record = record
        new_record["response_time"] = tonumber(new_record["response_time"])
        return 1, timestamp, new_record
end

function stringtonumber(tag, timestamp, record)
        new_record = record   
        new_record["time"] = new_record["time"]:gsub("Jan", "01"):gsub("Feb", "02"):gsub("Mar", "03"):gsub("Apr", "04"):gsub("May", "05"):gsub("Jun", "06"):gsub("Jul", "07"):gsub("Aug", "08"):gsub("Sep", "09"):gsub("Oct", "10"):gsub("Nov", "11"):gsub("Dev", "12")
        temp = {}
        for word in new_record["time"]:gmatch("%S+") do
                table.insert(temp, word)
        end
        new_record["time"] = string.format("%s-%s-%s %s.000", temp[4], temp[3], temp[2], temp[5])
end