[PATCH 07/11] testsuite: Use random free port for qemu SSH forwarding

[Uladzimir Bely <ubely@ilbers.de>]

Instead of using fixed 22222 port for forwarding to qemu port 22,
request free port from the system.

This allows to run qemu machines in parallel and also fixes possible
issues with sequential qemu test CI runs in case system delays port
release.

Signed-off-by: Uladzimir Bely <ubely@ilbers.de>
---
 testsuite/start_vm.py | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/testsuite/start_vm.py b/testsuite/start_vm.py
index d6c47dcd..d151232e 100755
--- a/testsuite/start_vm.py
+++ b/testsuite/start_vm.py
@@ -5,6 +5,7 @@
 
 import argparse
 import os
+import socket
 import subprocess
 import sys
 import time
@@ -70,9 +71,12 @@ def format_qemu_cmdline(arch, build, distro, image, out, pid, enforce_pcbios=Fal
         bios_idx = qemu_disk_args.index('-bios')
         del qemu_disk_args[bios_idx : bios_idx+2]
 
-    # Support SSH access from host via port 22222
+    # Support SSH access from host
+    ssh_sock = socket.socket()
+    ssh_sock.bind(('', 0))
+    ssh_port=ssh_sock.getsockname()[1]
     extra_args.extend(['-device', 'e1000,netdev=net0'])
-    extra_args.extend(['-netdev', 'user,id=net0,hostfwd=tcp::22222-:22'])
+    extra_args.extend(['-netdev', 'user,id=net0,hostfwd=tcp::' + str(ssh_port) + '-:22'])
 
     cmd = ['qemu-system-' + qemu_arch, '-m', '1024M']
 
-- 
2.20.1