util(disk): freebsd and netbsd support

util/disk/disk_freebsd.go

@@ -0,0 +1,22 @@
+//go:build freebsd
+
+package disk
+
+import (
+	"syscall"
+
+	"github.com/pkg/errors"
+)
+
+func GetDiskStat(root string) (DiskStat, error) {
+	var st syscall.Statfs_t
+	if err := syscall.Statfs(root, &st); err != nil {
+		return DiskStat{}, errors.Wrapf(err, "could not stat fs at %s", root)
+	}
+
+	return DiskStat{
+		Total:     int64(st.Bsize) * int64(st.Blocks),
+		Free:      int64(st.Bsize) * int64(st.Bfree),
+		Available: int64(st.Bsize) * int64(st.Bavail),
+	}, nil
+}

util/disk/disk_netbsd.go

@@ -0,0 +1,21 @@
+//go:build netbsd
+
+package disk
+
+import (
+	"github.com/pkg/errors"
+	"golang.org/x/sys/unix"
+)
+
+func GetDiskStat(root string) (DiskStat, error) {
+	var st unix.Statvfs_t
+	if err := unix.Statvfs(root, &st); err != nil {
+		return DiskStat{}, errors.Wrapf(err, "could not stat fs at %s", root)
+	}
+
+	return DiskStat{
+		Total:     int64(st.Frsize) * int64(st.Blocks),
+		Free:      int64(st.Frsize) * int64(st.Bfree),
+		Available: int64(st.Frsize) * int64(st.Bavail),
+	}, nil
+}

util/disk/disk_test.go

@@ -0,0 +1,15 @@
+package disk
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestGetDiskStat(t *testing.T) {
+	diskStat, err := GetDiskStat("/")
+	require.NoError(t, err)
+	require.Greater(t, diskStat.Total, int64(0))
+	require.GreaterOrEqual(t, diskStat.Free, int64(0))
+	require.GreaterOrEqual(t, diskStat.Available, int64(0))
+}

util/disk/disk_unix.go

@@ -1,4 +1,4 @@
-//go:build !windows && !openbsd
+//go:build !windows && !freebsd && !netbsd && !openbsd
 
 package disk