runtime: newContainer: Handle the annotations of SWAP

This commit add code to handle the annotations
"io.katacontainers.resource.swappiness" and
"io.katacontainers.resource.swap_in_bytes".
It will set the value of "io.katacontainers.resource.swappiness" to
c.config.Resources.Memory.Swappiness and set the value of
"io.katacontainers.resource.swap_in_bytes" to
c.config.Resources.Memory.Swap.

Fixes: kata-containers#2201

Signed-off-by: Hui Zhu <teawater@antfin.com>

src/runtime/virtcontainers/container.go

@@ -13,6 +13,7 @@ import (
 	"io"
 	"os"
 	"path/filepath"
+	"strconv"
 	"syscall"
 	"time"
 
@@ -35,6 +36,11 @@ import (
 	"golang.org/x/sys/unix"
 )
 
+const (
+	resourceSwappinessLabel  = "io.katacontainers.resource.swappiness"
+	resourceSwapInBytesLabel = "io.katacontainers.resource.swap_in_bytes"
+)
+
 // https://github.com/torvalds/linux/blob/master/include/uapi/linux/major.h
 // This file has definitions for major device numbers.
 var cdromMajors = map[int64]string{
@@ -772,6 +778,25 @@ func newContainer(ctx context.Context, sandbox *Sandbox, contConfig *ContainerCo
 		ctx:           sandbox.ctx,
 	}
 
+	// Set the Annotations of SWAP to Resources
+	if resourceSwappinessStr, ok := c.config.Annotations[resourceSwappinessLabel]; ok {
+		resourceSwappiness, err := strconv.ParseUint(resourceSwappinessStr, 0, 64)
+		if err == nil && resourceSwappiness > 200 {
+			err = fmt.Errorf("swapiness should not bigger than 200")
+		}
+		if err != nil {
+			return &Container{}, fmt.Errorf("Invalid container configuration Annotations %s %v", resourceSwappinessLabel, err)
+		}
+		c.config.Resources.Memory.Swappiness = &resourceSwappiness
+	}
+	if resourceSwapInBytesStr, ok := c.config.Annotations[resourceSwapInBytesLabel]; ok {
+		resourceSwapInBytes, err := strconv.ParseInt(resourceSwapInBytesStr, 0, 64)
+		if err != nil {
+			return &Container{}, fmt.Errorf("Invalid container configuration Annotations %s %v", resourceSwapInBytesLabel, err)
+		}
+		c.config.Resources.Memory.Swap = &resourceSwapInBytes
+	}
+
 	// experimental runtime use "persist.json" instead of legacy "state.json" as storage
 	err := c.Restore()
 	if err == nil {