Expected behavior:

I can configure Telegraf to pass metrics from named pipe into InfluxDB, without loss of data. This worked fine with Telegraf 1.2 (I know, that's ancient).

Writing of this tag should be configurable.

Actual behavior:

tail input overwrites path tag: https://github.com/influxdata/telegraf/blob/release-1.14/plugins/inputs/tail/tail.go#L231 , breaking any path tag that can come from tailed file.