log4js appenders with webpack

Question

Log4js uses dynamic require for loading appenders. Webpack doesn't know at build time which appender will be used at runtime.

How can I use not build in appenders? like @log4js-node/logstashudp

score 1 · Accepted Answer · answered Jan 16 '22 at 08:55

Let's say you want to add a new appender (that's not build in like tcp,file) like @log4js-node/logstashudp or any other appender.

So instead of:

log4js.configure({
  appenders: {
    udpAppender: {
      type: '@log4js-node/logstashudp',
      .....
    }
  }
})

You need to do it like this:

import * as udp from '@log4js-node/logstashudp'
log4js.configure({
  appenders: {
    udpAppender: {
      type: udp,
      .....
    }
  }
})

In short, you should load your module and send it in type property.

Therefore, appender's module wont load in runtime and the webpack problem is solved!

1 Answers1