Add support for paths in output.influxdb

[crenz]

Feature Request

Proposal:

I propose to add support for InfluxDB URLs that contain paths. As of today, the configuration is an URL, which kind of suggests that paths are supported – when in reality they are not. Here is an example:

[[outputs.influxdb]]
  urls = ["http://influxdb.example.com/api"]

Current behavior:

For the example above, telegraf will only extract the host name and port, and issue a request to e.g. http://influxdb.example.com/query?…

Desired behavior:

telegraf should make use of the URI as well and issue a request to e.g. http://influxdb.example.com/api/query?…

Use case: [Why is this important (helps with prioritizing requests)]

This feature will be very helpful for setups where InfluxDB resides behind a reverse proxy, such as nginx.

[danielnelson]

This was added in #3224, will be in 1.5.0