types: create simpler ScanPriorDrivers for options

Signed-off-by: Aditya R <arajan@redhat.com>

pkg/fsutils/utils.go

@@ -0,0 +1,29 @@
+package fsutils
+
+import (
+	"path/filepath"
+	"os"
+)
+
+
+var Drivers = []string{
+		"overlay",
+		"aufs",
+		"btrfs",
+		"zfs",
+		"vfs",
+	}
+
+// scanPriorDrivers returns an un-ordered scan of directories of prior storage drivers
+func ScanPriorDrivers(root string) map[string]bool {
+	driversMap := make(map[string]bool)
+
+	for _, driver := range Drivers {
+		p := filepath.Join(root, driver)
+		if _, err := os.Stat(p); err == nil {
+			driversMap[driver] = true
+		}
+	}
+	return driversMap
+}
+

pkg/fsutils/utils_darwin.go

@@ -0,0 +1,13 @@
+//go:build darwin
+// +build darwin
+
+package fsutils
+
+
+var (
+	// Slice of drivers that should be used in an order
+	DriverPriority = []string{
+		"zfs",
+		"vfs",
+	}
+)

pkg/fsutils/utils_freebsd.go

@@ -0,0 +1,13 @@
+//go:build freebsd
+// +build freebsd
+
+package fsutils
+
+
+var (
+	// Slice of drivers that should be used in an order
+	DriverPriority = []string{
+		"zfs",
+		"vfs",
+	}
+)

pkg/fsutils/utils_linux.go

@@ -0,0 +1,18 @@
+//go:build linux
+// +build linux
+
+package fsutils
+
+
+var (
+	// Slice of drivers that should be used in an order
+	DriverPriority = []string{
+		"overlay",
+		// We don't support devicemapper without configuration
+		// "devicemapper",
+		"aufs",
+		"btrfs",
+		"zfs",
+		"vfs",
+	}
+)

pkg/fsutils/utils_solaris.go

@@ -0,0 +1,12 @@
+//go:build solaris && cgo
+// +build solaris,cgo
+
+package fsutils
+
+
+var (
+	// Slice of drivers that should be used in an order
+	DriverPriority = []string{
+		"zfs",
+	}
+)

pkg/fsutils/utils_unsupported.go

@@ -0,0 +1,11 @@
+//go:build !linux && !windows && !freebsd && !solaris && !darwin
+// +build !linux,!windows,!freebsd,!solaris,!darwin
+
+package fsutils
+
+var (
+	// Slice of drivers that should be used in an order
+	DriverPriority = []string{
+		"unsupported",
+	}
+)

pkg/fsutils/utils_windows.go

@@ -0,0 +1,12 @@
+//go:build windows
+// +build windows
+
+package fsutils
+
+
+var (
+	// Slice of drivers that should be used in an order
+	DriverPriority = []string{
+		"windowsfilter",
+	}
+)

types/options.go

@@ -10,9 +10,8 @@ import (
 	"time"
 
 	"github.com/BurntSushi/toml"
-	drivers "github.com/containers/storage/drivers"
-	_ "github.com/containers/storage/drivers/register"
 	cfg "github.com/containers/storage/pkg/config"
+	"github.com/containers/storage/pkg/fsutils"
 	"github.com/containers/storage/pkg/idtools"
 	"github.com/sirupsen/logrus"
 )
@@ -312,9 +311,9 @@ func getRootlessStorageOpts(rootlessUID int, systemOpts StoreOptions) (StoreOpti
 	}
 	if opts.GraphDriverName == "" {
 		if len(systemOpts.GraphDriverPriority) == 0 {
-			driversMap := drivers.ScanPriorDrivers(opts.GraphRoot)
+			driversMap := fsutils.ScanPriorDrivers(opts.GraphRoot)
 
-			for _, name := range drivers.Priority {
+			for _, name := range fsutils.DriverPriority {
 				if _, prior := driversMap[name]; prior {
 					opts.GraphDriverName = name
 					break