log4js-node mask sensitive details while logging

Question

Could anyone help on masking sensitive fields using log4js in node? Found similar filters in winston logger but if something similar is available in log4js, it would be helpful.

Answer 1

I found some workaround.

For example, if you want to have log in pattern: "%r %p %c %m%n" where %r - time, %p - log level, %c - log category, %m - log data, %n - newline.

And if you want to mask some sensitive data in %m, you can do it in this way:

Add layout to your appender:

    layout: {
         type    : "pattern",
         pattern : "%r %p %c {%x{body}}%n",
         tokens: {
             body : function() {
                 var msg = arguments[0].data[0];
                 return maskSensitiveData(msg);
             }
         }
     }

and then implement function

var maskSensitiveData = function(msg) {
    ...
}