allow measurement to be defined for logparser_grok plugin

[nathanielc]

Allows the logparser plugin to define the measurement for the data. I know that normally this is not configurable but it seems to make sense for the logparser plugin as what is being parsed can vary significantly. Also this is the only way to separate data from multiple instances of the plugin.

New example config:

[[inputs.logparser]]
   files = ["/var/lib/pmacct/in_port.txt"]
   from_beginning = true
   [inputs.logparser.grok]
     measurement = "net_in_port"
     patterns = ["%{NONNEGINT:port:tag},%{NONNEGINT:packets:int},%{NONNEGINT:bytes:int}"]

[[inputs.logparser]]
   files = ["/var/lib/pmacct/out_port.txt"]
   from_beginning = true
   [inputs.logparser.grok]
     measurement = "net_out_port"
     patterns = ["%{NONNEGINT:port:tag},%{NONNEGINT:packets:int},%{NONNEGINT:bytes:int}"]

• CHANGELOG.md updated
• README.md updated (if adding a new plugin)

[sparrc]

looks good but you need to run go fmt and add something to the sampleConfig as well

[toni-moreno]

+1