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javaregexlogginglogback

Masking sensitive logs using regex

I am trying to mask the logs by chaining replace regex in logback.xml file.

%replace(%replace(%msg){'"email":(.*?),','"email":"****"'}){'"phone":(.*?),','"phone":"****"'}))

It's working, but is there any other regex solution instead of regex replace chaining?

Can we use regex something like this?

(%replace(%msg){'"(email|phone)":(:*?)','"***",'}

I tried the above but the format is not proper.

Required output is:

{"email":"****","phone":"****"}
Solution

  • You can use

    (%replace(%msg){'"(email|phone)":[^,]*,?','"$1":"****"'})

    The "(email|phone)":[^,]*,? regex matches

    • " - a " char
    • (email|phone) - Group 1 ($1): email or phone string
    • ": - a ": string
    • [^,]* - zero or more chars other than a comma
    • ,? - an optional , char.

    The replacement is "$1":"****": " + Group 1 value + ":"***".

    See the regex demo.