Grok pattern for [Mon Jan 04 08:36:12 2021]

Question

I am working on shipping some logs to elasticsearch using logstash. I am unable to figure out the grok pattern for [Mon Jan 04 08:36:12 2021] .The format is Day Month Date Time Year Help and Suggestions are most welcome.

Log - [Mon Jan 04 08:36:12 2021]
Grok I tried - \[%{DAY:day} %{MONTH:month} %{TIME:time} %{YEAR:year}]
Result Expected - Day:Mon Month:Jan Date:04 Hour:08 Minute:36 Second:12 Year:2021

Answer 1

You forgot to specify the %{MONTHDAY} in between the month and time variables.

You can use

\[%{DAY:day} %{MONTH:month} %{MONTHDAY} %{TIME:time} %{YEAR:year}]

Grok pattern list used:

• DAY (?:Mon(?:day)?|Tue(?:sday)?|Wed(?:nesday)?|Thu(?:rsday)?|Fri(?:day)?|Sat(?:urday)?|Sun(?:day)?)
• MONTH \b(?:[Jj]an(?:uary|uar)?|[Ff]eb(?:ruary|ruar)?|[Mm](?:a|ä)?r(?:ch|z)?|[Aa]pr(?:il)?|[Mm]a(?:y|i)?|[Jj]un(?:e|i)?|[Jj]ul(?:y|i)?|[Aa]ug(?:ust)?|[Ss]ep(?:tember)?|[Oo](?:c|k)?t(?:ober)?|[Nn]ov(?:ember)?|[Dd]e(?:c|z)(?:ember)?)\b
• MONTHDAY (?:(?:0[1-9])|(?:[12][0-9])|(?:3[01])|[1-9])
• TIME (?!<[0-9])%{HOUR}:%{MINUTE}(?::%{SECOND})(?![0-9])
  • HOUR (?:2[0123]|[01]?[0-9])
  • MINUTE (?:[0-5][0-9])
  • SECOND (?:(?:[0-5]?[0-9]|60)(?:[:.,][0-9]+)?)
• YEAR (?>\d\d){1,2}