Use error.Error() string for log attributes

[ejsolberg]

Links

Running against the latest agent version v3.34.0

w/ Logrus LogsInContext configured (doc)

Related to new functionality added in
Capture Log Attributes in the Agent #900
Using Logrus attributes #937

Details

Currently, when errors are logged with the Logs in Context integration, the type is emitted instead of the error string.

log.WithError(fmt.Errorf("this is the error message")).Error("Something went wrong")

Console output:

{"error":"this is the error message","level":"error","msg":"Something went wrong"}

NewRelic Log:

{"error":"*errors.errorString","level":"error","msg":"Something went wrong"}

This change aligns the NewRelic log attribute with the console output

[CLAassistant]

All committers have signed the CLA.

[iamemilio]

Hi, thanks for this contribution! Can you rebase it against develop? That is where we stage all of our commits. Otherwise, it looks good!

[ejsolberg]

Hi @iamemilio, thanks for the initial review! I've rebased to develop