use random port in testing

Makefile

@@ -1,4 +1,4 @@
-PUIPUI_LINUX_VERSION := 1.0.1
+PUIPUI_LINUX_VERSION := 1.0.2
 ARCH := $(shell uname -m)
 KERNEL_ARCH := $(shell echo $(ARCH) | sed -e s/arm64/aarch64/)
 KERNEL_TAR := puipui_linux_v$(PUIPUI_LINUX_VERSION)_$(KERNEL_ARCH).tar.gz
@@ -36,4 +36,4 @@ install/stringer:
 
 .PHONY: clean
 clean:
-	@rm testdata/{Image,initramfs.cpio.gz,*.tar.gz}
+	@rm testdata/{Image,initramfs.cpio.gz,*.tar.gz}

virtualization_test.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"math"
+	"net"
 	"os"
 	"runtime"
 	"syscall"
@@ -112,15 +113,30 @@ func (c *Container) NewSession(t *testing.T) *ssh.Session {
 	return sshSession
 }
 
+func getFreePort() (int, error) {
+	l, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		return 0, err
+	}
+	defer l.Close()
+	return l.Addr().(*net.TCPAddr).Port, nil
+}
+
 func newVirtualizationMachine(
 	t *testing.T,
 	configs ...func(*vz.VirtualMachineConfiguration) error,
 ) *Container {
+	port, err := getFreePort()
+	if err != nil {
+		t.Fatalf("failed to resolve free tcp addr: %v", err)
+	}
+
 	vmlinuz := "./testdata/Image"
 	initramfs := "./testdata/initramfs.cpio.gz"
+	cmdline := fmt.Sprintf("console=hvc0 vsock_port=%d", port)
 	bootLoader, err := vz.NewLinuxBootLoader(
 		vmlinuz,
-		vz.WithCommandLine("console=hvc0"),
+		vz.WithCommandLine(cmdline),
 		vz.WithInitrd(initramfs),
 	)
 	if err != nil {
@@ -176,7 +192,7 @@ func newVirtualizationMachine(
 	max := 8
 RETRY:
 	for i := 1; ; i++ {
-		conn, err := socketDevice.Connect(2222)
+		conn, err := socketDevice.Connect(uint32(port))
 		if err != nil {
 			var nserr *vz.NSError
 			if !errors.As(err, &nserr) || i > max {