Windows: win_perf_counters won't load on Server Core installations due to missing Windows API libraries

[someone1]

Bug report

Relevant telegraf.conf:

Standard one shipped with Windows client download

System info:

Telegraf: v1.0.0
Operating System: "Microsoft Hyper-V Server 2012 R2" & "Microsoft Windows Server 2012 R2 Standard"

Steps to reproduce:

1. Try to execute any options on telegraf on a Server Core installation

Expected behavior:

To execute normally

Actual behavior:

Panic:

panic: The specified module could not be found.

goroutine 1 [running]:
panic(0x12fcb00, 0xc0820fc990)
        /usr/local/go/src/runtime/panic.go:481 +0x3f4
github.com/lxn/win.MustLoadLibrary(0x14b9480, 0xc, 0xc)
        /home/ubuntu/telegraf-build/src/github.com/lxn/win/win.go:48 +0x79
github.com/lxn/win.init.9()
        /home/ubuntu/telegraf-build/src/github.com/lxn/win/opengl32.go:117 +0x37

github.com/lxn/win.init()
        /home/ubuntu/telegraf-build/src/github.com/lxn/win/winspool.go:100 +0x78

github.com/influxdata/telegraf/plugins/inputs/win_perf_counters.init()
        /home/ubuntu/telegraf-build/src/github.com/influxdata/telegraf/plugins/i
nputs/win_perf_counters/win_perf_counters.go:332 +0x62
github.com/influxdata/telegraf/plugins/inputs/all.init()
        /home/ubuntu/telegraf-build/src/github.com/influxdata/telegraf/plugins/i
nputs/all/all.go:79 +0x18b
main.init()
        /home/ubuntu/telegraf-build/src/github.com/influxdata/telegraf/cmd/teleg
raf/telegraf.go:323 +0x85

Additional info:

I dug around and it looks like the line /home/ubuntu/telegraf-build/src/github.com/lxn/win/opengl32.go:117 is trying to load a "opengl32.dll" which I'm guessing is a windows drawing component that doesn't ship with server core installations. Maybe a new interface for querying the performance counters can be used that doesn't put any dependencies on features not required for querying?

[JeffAshton]

Opened pull request #2017 to address this