glog parser's "glog_timestamp" field can't be used as the event's timestamp

[seh]

For the parsers like "json" and "keyval" that confront timestamp fields as text, it's possible to use the "timefield" and "drop_field" processors to "move" those fields to the primary timestamp of the posted log event. That is, say that there's a log record in "keyval" format with a field named "ts," with its values as RFC 3339 strings. You can write the following to make the "ts" field's time the event's time:

- dataset: "My Dataset"
  namespace: kube-system
  labelSelector: "app = prometheus-node-exporter"
  parser: keyval
  processors:
  - timefield:
      field: time
      format: "2006-01-02T15:04:05Z07:00" # RFC 3339
  - drop_field:
      field: time

However, with the "glog" format, it tries to help by parsing the expected time string into a time.Time value, and stashing it in the "glog_timestamp" field. It's not possible to later "move" this "glog_timestamp" field into the event's timestamp, because the "timefield" processor only consumes fields with values of type string or int.

It would be nice if the "timefield" processor could treat the "format" configuration field as optional (maybe it already does), and if it's absent, tolerate extracting a field that's already of type time.Time. If it could do that, we could promote the "glog_timestamp" field like this:

- dataset: "My Dataset"
  namespace: kube-system
  labelSelector: "k8s-app notin (calico-node, calico-typha)"
  parser: glog
  processors:
  - timefield:
      field: glog_timestamp
  - drop_field:
      field: glog_timestamp

[tredman]

This is fixed in 1.3.0

[seh]

I confirmed that this works as expected. Thank you.