feat: add path tag to file input

[RodrigoDornelles]

Use Case

my use case would be as follows, I am using the hostname of the container in the folder path, I would like to retrieve it as host in my indexing. I think it would be interesting to have a path_tag configuration to extract this! or file_tag_fullname to set to true or false to get all filepath name with file.

Expected behavior

[[inputs.file]]
  files = ["/logs/*/*.log"]
  file_tag = "system"
  path_tag = "host"
  influx_timestamp_precision = "1s"

[[processors.regex]]
 [[processors.regex.tags]]
    key = "system"
    pattern = "^([a-z0-9]+)(-.+)"
    replacement = "${1}"
 [[processors.regex.tags]]
    key = "host"
    pattern = "^/logs/(\\w+)/$"
    replacement = "${1}"

get tags system and host

Actual behavior

only can get file.

Additional info

No response

[powersj]

Happy to see a PR for this that would add a path_tag config option that adds the path, versus the file name, which is what file_tag does today. This would of course default to false and should probably have a warning as well about possible carnality in the config option comments.

[Hipska]

Hmm, I think it makes more sense to have an extra option to enable the full file name in the existing tag.

Current:

metric,file=telegraf.log msg="foobar"

New:

metric,file=/var/log/telegraf.log msg="foobar"