Refactor: Rename NanoKVM to BatchuKVM and update server URL

server/service/vm/swap.go

@@ -0,0 +1,176 @@
+package vm
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+	"time"
+
+	"NanoKVM-Server/proto"
+
+	"github.com/gin-gonic/gin"
+	log "github.com/sirupsen/logrus"
+)
+
+const (
+	SwapFile    = "/swapfile"
+	InittabPath = "/etc/inittab"
+	TempInittab = "/etc/.inittab.tmp"
+)
+
+func (s *Service) GetSwap(c *gin.Context) {
+	var rsp proto.Response
+
+	rsp.OkRspWithData(c, &proto.GetSwapRsp{
+		Size: getSwapSize(),
+	})
+}
+
+func (s *Service) SetSwap(c *gin.Context) {
+	var rsp proto.Response
+	var req proto.SetSwapReq
+
+	if err := proto.ParseFormRequest(c, &req); err != nil {
+		rsp.ErrRsp(c, -1, "invalid arguments")
+		return
+	}
+
+	size := getSwapSize()
+	if req.Size == size {
+		rsp.OkRsp(c)
+		return
+	}
+
+	if req.Size == 0 {
+		if err := disableSwap(); err != nil {
+			rsp.ErrRsp(c, -2, "disable swap failed")
+			return
+		}
+		if err := disableInittab(); err != nil {
+			rsp.ErrRsp(c, -3, "disable inittab failed")
+			return
+		}
+	} else {
+		if err := enableSwap(req.Size); err != nil {
+			rsp.ErrRsp(c, -4, "enable swap failed")
+			return
+		}
+		if err := enableInittab(); err != nil {
+			rsp.ErrRsp(c, -5, "enable inittab failed")
+			return
+		}
+	}
+
+	rsp.OkRsp(c)
+}
+
+func getSwapSize() int64 {
+	fileInfo, err := os.Stat(SwapFile)
+	if err != nil {
+		return 0
+	}
+
+	return fileInfo.Size() / 1024 / 1024
+}
+
+func enableSwap(size int64) error {
+	if getSwapSize() > 0 {
+		if err := disableSwap(); err != nil {
+			return err
+		}
+	}
+
+	commands := []string{
+		fmt.Sprintf("fallocate -l %dM %s", size, SwapFile),
+		fmt.Sprintf("chmod 600 %s", SwapFile),
+		fmt.Sprintf("mkswap %s", SwapFile),
+		fmt.Sprintf("swapon %s", SwapFile),
+	}
+
+	for _, command := range commands {
+		err := exec.Command("sh", "-c", command).Run()
+		if err != nil {
+			log.Errorf("failed to execute %s: %s", command, err)
+			return err
+		}
+
+		time.Sleep(300 * time.Millisecond)
+	}
+
+	log.Debugf("set swap file size: %d", size)
+	return nil
+}
+
+func disableSwap() error {
+	command := "swapoff -a"
+	if err := exec.Command("sh", "-c", command).Run(); err != nil {
+		log.Errorf("failed to execute swapoff: %s", err)
+		return err
+	}
+
+	if err := os.Remove(SwapFile); err != nil {
+		log.Errorf("failed to delete %s: %s", SwapFile, err)
+		return err
+	}
+
+	return nil
+}
+
+func enableInittab() error {
+	f, err := os.OpenFile(InittabPath, os.O_APPEND|os.O_WRONLY, 0644)
+	if err != nil {
+		log.Errorf("read inittab failed: %s", err)
+		return err
+	}
+	defer func() {
+		_ = f.Close()
+	}()
+
+	content := fmt.Sprintf("\nsi11::sysinit:/sbin/swapon %s", SwapFile)
+	_, err = f.WriteString(content)
+	if err != nil {
+		log.Errorf("write inittab failed: %s", err)
+		return err
+	}
+
+	log.Debugf("write to %s: %s", InittabPath, content)
+	return nil
+}
+
+func disableInittab() error {
+	defer func() {
+		_ = os.Remove(TempInittab)
+	}()
+
+	input, err := os.ReadFile(InittabPath)
+	if err != nil {
+		log.Errorf("read fstab failed: %s", err)
+		return err
+	}
+
+	lines := strings.Split(string(input), "\n")
+	output := make([]string, 0)
+
+	for _, line := range lines {
+		if strings.HasSuffix(line, SwapFile) {
+			log.Debugf("%s delete line: %s", InittabPath, line)
+		} else {
+			output = append(output, line)
+		}
+	}
+
+	content := strings.Join(output, "\n")
+	content = strings.TrimSuffix(content, "\n")
+	if err := os.WriteFile(TempInittab, []byte(content), 0644); err != nil {
+		log.Errorf("write temp fstab failed: %s", err)
+		return err
+	}
+
+	if err := os.Rename(TempInittab, InittabPath); err != nil {
+		log.Errorf("replace fstab failed: %s", err)
+		return err
+	}
+
+	return nil
+}