New Relic Logrus Hook

This is a simple logrus hook that lets existing logrus applications hook into New Relic error reporting using the New Relic Go Agent.

New Relic relies on having errors associated witha transaction. But logrus doesn't know which transaction its being called from. So, you have two options:

• Pass nothing and a new New Relic transaction will be created and the error associatied with that.
• Use WithFields(logrus.Fields{"txn": tx}).Error(...) and pass in your existing transaction. This will be used instead.

If you use the second strategy, you should also use the included Formatter to remove the txn field from the logs. The Formatter can also masque any fields you wish to prevent from being logged in the clear.

In either case, if any fields are supplied to the log line via WithFields, they are reported as custom attributes on the errorTxn and will be visible in New Relic.

Usage

You can install this like any other logrus hook. Assuming that application is your newrelic.Application from the Go agent, you can "hook" it up like this:

log.AddHook(
	newrelic_logrus.NewNewRelicLogrusHook(
		application,
		[]log.Level{log.ErrorLevel, log.FatalLevel},
	),
)

The following will enable filtered txn from your logs, and will also allow filtering of any fields entitled password. You may specify any underlying logrus formatter you like. In this case we use the normal TextFormatter.

formatter := NewFormatter([]string{"password"}, &log.TextFormatter{})
log.SetFormatter(formatter)