Add windows version generation

internal/version/.gitignore

@@ -0,0 +1 @@
+version.go

internal/version/generate_nix.go

@@ -1,4 +1,5 @@
 // +build darwin,dragonfly,freebsd,linux,netbsd,openbsd,solaris
+
 package version
 
 //go:generate sh ./generate_nix.sh

internal/version/generate_win.go

@@ -0,0 +1,5 @@
+// +build windows
+
+package version
+
+//go:generate powershell .\generate_win.ps1

internal/version/generate_win.ps1

@@ -0,0 +1,13 @@
+$GitCommitId = &("git.exe") log -n1 --format="%h"
+$GitCommitId = $GitCommitId.Trim()
+
+@"
+// Code generated automatically; DO NOT EDIT.
+package version
+
+var (
+  // GitCommitId provides the git commit id used to build this service.
+  GitCommitId = "$GitCommitId"
+)
+
+"@ | Out-File -Encoding ASCII -FilePath version.go

internal/version/version.go

@@ -1,7 +0,0 @@
-// Code generated automatically; DO NOT EDIT.
-package version
-
-var (
-  // GitCommitId provides the git commit id used to build this service.
-  GitCommitId string = "c198177"
-)