Fix undefined process.Processes when building telegraf on Solaris-based system

[szaydel]

I attempted to build telegraf today on OmniOS, which is a Solaris derived system, but based on the Illumos kernel, and ran into this issue. A bit of digging revealed that nothing builds that would satisfy this requirement. As such, this hack happened.

# github.com/influxdata/telegraf/plugins/inputs/procstat
plugins/inputs/procstat/native_finder.go:24:16: undefined: process.Processes
plugins/inputs/procstat/native_finder_notwindows.go:18:16: undefined: process.Processes
plugins/inputs/procstat/native_finder_notwindows.go:43:16: undefined: process.Processes

It seems like there's not really much there to support process information on Solaris and friends, and I am wondering if there is any demand, and if so, I have done some work to expose but a small subset of what seems to be made available from other operating systems, but perhaps if there is interest, I can at least add a few of those bits as time permits and maybe enhance from there.

Thanks, Sam.

[Lomanic]

You might be interested in #378 that adds some support for Illumos.

About your PR, I don't have any objections, it would fix compilation for any platform not currently implemented, the error will appear at runtime instead.

[szaydel]

This sounds good. I did look at that PR, and I see that there's nothing for process, which is what telegraf actually demands. I think I could add memory bits if there's interest, at least 64bit support initially. If you don't mind pulling in this PR, it will make it easier for me to build telegraf. :)

Thanks!

[shirou]

I think this PR is not only Solaris-based system but also other systems. And we can check err to avoid runtime error after build success. Thank you for your contribution!

[szaydel]

Glad to contribute in a tiny way. I will look into getting Solaris-centric process information and making it available through psutil. It would be nice to have.