chore: wip on missing optional features

container/container_init.go

@@ -73,6 +73,7 @@ func (c *Container) Init(reexecCmd string, reexecArgs []string) error {
 			})
 		}
 
+		// FIXME: why does this segfault??
 		// if ns.Type == specs.TimeNamespace {
 		// 	if c.Spec.Linux.TimeOffsets != nil && len(c.Spec.Linux.TimeOffsets) > 0 {
 		// 		var tos bytes.Buffer

container/container_reexec.go

@@ -117,20 +117,10 @@ func (c *Container) Reexec() error {
 	}
 
 	if c.Spec.Linux.Sysctl != nil {
-		if len(c.Spec.Linux.Sysctl) > 0 {
-			// fmt.Println(c.Spec.Linux.Sysctl)
-			// for k, v := range c.Spec.Linux.Sysctl {
-			// fmt.Print(k, v)
-			// kp := strings.ReplaceAll(k, ".", "/")
-			// if err := os.WriteFile(
-			// 	path.Join("/proc/sys", kp),
-			// 	[]byte(v),
-			// 	0644,
-			// ); err != nil {
-			// 	// return fmt.Errorf("write sysctl (%s: %s): %w", kp, v, err)
-			// }
-			// }
-		}
+		// FIXME: why does this segfault??
+		// if err := sysctl.SetSysctl(c.Spec.Linux.Sysctl); err != nil {
+		// 	return fmt.Errorf("set sysctl: %w", err)
+		// }
 	}
 
 	if err := filesystem.MountMaskedPaths(
@@ -215,7 +205,12 @@ func (c *Container) Reexec() error {
 		}
 	}
 
-	// TODO: IOPriority
+	if c.Spec.Process.IOPriority != nil {
+		// FIXME: why does this segfault??
+		// if err := iopriority.SetIOPriority(*c.Spec.Process.IOPriority); err != nil {
+		// 	return fmt.Errorf("set iop: %w", err)
+		// }
+	}
 
 	if err := syscall.Setuid(int(c.Spec.Process.User.UID)); err != nil {
 		return fmt.Errorf("set UID: %w", err)

iopriority/iopriority.go

@@ -0,0 +1,29 @@
+package iopriority
+
+import (
+	"fmt"
+
+	"github.com/opencontainers/runtime-spec/specs-go"
+	"golang.org/x/sys/unix"
+)
+
+var IOPrioClassMapping = map[specs.IOPriorityClass]int{
+	specs.IOPRIO_CLASS_RT:   1,
+	specs.IOPRIO_CLASS_BE:   2,
+	specs.IOPRIO_CLASS_IDLE: 3,
+}
+
+func SetIOPriority(iop specs.LinuxIOPriority) error {
+	class, ok := IOPrioClassMapping[iop.Class]
+	if !ok {
+		return fmt.Errorf("unknown ioprio class: %s", iop.Class)
+	}
+
+	ioprio := (class << 13) | iop.Priority
+
+	if _, _, errno := unix.Syscall(unix.SYS_IOPRIO_SET, 1, 0, uintptr(ioprio)); errno != 0 {
+		return fmt.Errorf("set io priority: %w", errno)
+	}
+
+	return nil
+}

sysctl/sysctl.go

@@ -0,0 +1,24 @@
+package sysctl
+
+import (
+	"fmt"
+	"os"
+	"path"
+	"strings"
+)
+
+func SetSysctl(sc map[string]string) error {
+	for k, v := range sc {
+		fmt.Print(k, v)
+		kp := strings.ReplaceAll(k, ".", "/")
+		if err := os.WriteFile(
+			path.Join("/proc/sys", kp),
+			[]byte(v),
+			0644,
+		); err != nil {
+			return fmt.Errorf("write sysctl (%s: %s): %w", kp, v, err)
+		}
+	}
+
+	return nil
+}