Enable integration tests on Windows using snapshotter and differ

Signed-off-by: Darren Stahl <darst@microsoft.com>

sys/filesys_unix.go

@@ -0,0 +1,10 @@
+// +build !windows
+
+package sys
+
+import "os"
+
+// ForceRemoveAll on unix is just a wrapper for os.RemoveAll
+func ForceRemoveAll(path string) error {
+	return os.RemoveAll(path)
+}

sys/filesys_windows.go

@@ -11,6 +11,7 @@ import (
 	"unsafe"
 
 	winio "github.com/Microsoft/go-winio"
+	"github.com/Microsoft/hcsshim"
 )
 
 // MkdirAllWithACL is a wrapper for MkdirAll that creates a directory
@@ -234,3 +235,13 @@ func syscallOpenSequential(path string, mode int, _ uint32) (fd syscall.Handle,
 	h, e := syscall.CreateFile(pathp, access, sharemode, sa, createmode, fileFlagSequentialScan, 0)
 	return h, e
 }
+
+// ForceRemoveAll is the same as os.RemoveAll, but uses hcsshim.DestroyLayer in order
+// to delete container layers.
+func ForceRemoveAll(path string) error {
+	info := hcsshim.DriverInfo{
+		HomeDir: filepath.Dir(path),
+	}
+
+	return hcsshim.DestroyLayer(info, filepath.Base(path))
+}