Rework test_checkpoint

This test used the Git Bash environment and therefore often failed on
Windows.

Use PowerShell instead, which required adapting several VM methods to
use the PowerShell alternatives, as well as some behavior changes.

Signed-off-by: Tu Dinh <[email protected]>

Author: dinhngtu

lib/vm.py

@@ -176,13 +176,23 @@ def wait_for_vm_running_and_ssh_up(self):
         self.wait_for_os_booted()
         wait_for(self.is_ssh_up, "Wait for SSH up")
 
-    def ssh_touch_file(self, filepath):
+    def touch_file(self, filepath):
+        """
+        Make sure that a file exists. Do not change file contents.
+
+        On Windows, it uses PowerShell path format and may not update timestamps.
+        """
         logging.info("Create file on VM (%s)" % filepath)
-        self.ssh(['touch', filepath])
-        if not self.is_windows:
+        if self.is_windows:
+            self.execute_powershell_script(f'New-Item -ErrorAction SilentlyContinue -Type File -Path {filepath}')
+        else:
+            self.ssh(['touch', filepath])
             self.ssh(['sync', filepath])
         logging.info("Check file created")
-        self.ssh(['test -f ' + filepath])
+        if self.is_windows:
+            assert self.file_exists(filepath)
+        else:
+            self.ssh(['test -f ' + filepath])
 
     def suspend(self, verify=False):
         logging.info("Suspend VM")
@@ -403,7 +413,18 @@ def start_background_process(self, cmd: str) -> str:
             return pid
 
     def pid_exists(self, pid):
-        return self.ssh_with_result(['kill', '-s', '0', pid]).returncode == 0
+        if self.is_windows:
+            return strtobool(
+                self.execute_powershell_script(f'$null -ne (Get-Process -Id {pid} -ErrorAction SilentlyContinue)')
+            )
+        else:
+            return self.ssh_with_result(['kill', '-s', '0', pid]).returncode == 0
+
+    def kill_process(self, pid):
+        if self.is_windows:
+            self.execute_powershell_script(f'Get-Process -Id {pid} | Stop-Process')
+        else:
+            self.ssh(['kill ' + pid])
 
     def execute_script(self, script_contents, simple_output=True):
         with tempfile.NamedTemporaryFile('w') as f:
@@ -443,9 +464,16 @@ def tools_version(self):
         return "{major}.{minor}.{micro}-{build}".format(**version_dict)
 
     def file_exists(self, filepath, regular_file=True):
-        """Returns True if the file exists, otherwise returns False."""
-        option = '-f' if regular_file else '-e'
-        return self.ssh_with_result(['test', option, filepath]).returncode == 0
+        """
+        Returns True if the file exists, otherwise returns False.
+
+        regular_file does not apply to Windows.
+        """
+        if self.is_windows:
+            return strtobool(self.execute_powershell_script(f'Test-Path {filepath}'))
+        else:
+            option = '-f' if regular_file else '-e'
+            return self.ssh_with_result(['test', option, filepath]).returncode == 0
 
     def detect_package_manager(self):
         """ Heuristic to determine the package manager on a unix distro. """
@@ -472,13 +500,16 @@ def test_snapshot_on_running_vm(self):
         self.wait_for_vm_running_and_ssh_up()
         snapshot = self.snapshot()
         try:
-            filepath = '/tmp/%s' % snapshot.uuid
-            self.ssh_touch_file(filepath)
+            if self.is_windows:
+                filepath = fr'$Env:Temp\{snapshot.uuid}'
+            else:
+                filepath = '/tmp/%s' % snapshot.uuid
+            self.touch_file(filepath)
             snapshot.revert()
             self.start()
             self.wait_for_vm_running_and_ssh_up()
             logging.info("Check file does not exist anymore")
-            self.ssh(['test ! -f ' + filepath])
+            assert not self.file_exists(filepath)
         finally:
             snapshot.destroy(verify=True)
 
@@ -767,15 +798,16 @@ def run_powershell_command(self, program: str, args: str):
 
     def start_background_powershell(self, cmd: str):
         """
-        Run command under powershell in the background.
+        Run command under powershell in the background. Return the resulting PID.
 
         Backslash-safe.
         """
         assert self.is_windows
         encoded_command = commands.encode_powershell_command(cmd)
-        self.ssh(
+        return self.ssh(
             "powershell.exe -noprofile -noninteractive Invoke-WmiMethod -Class Win32_Process -Name Create "
-            f"-ArgumentList \\'powershell.exe -noprofile -noninteractive -encodedcommand {encoded_command}\\'"
+            f"-ArgumentList \\'powershell.exe -noprofile -noninteractive -encodedcommand {encoded_command}\\' \\|"
+            "Select-Object -Expand ProcessId"
         )
 
     def is_windows_pv_device_installed(self):

tests/misc/test_vm_basic_operations.py

@@ -23,24 +23,28 @@ def test_snapshot(self, running_vm: VM):
         vm = running_vm
         vm.test_snapshot_on_running_vm()
 
-    # When using a windows VM the background ssh process is never terminated
-    # This results in a ResourceWarning
-    @pytest.mark.filterwarnings("ignore::ResourceWarning")
     def test_checkpoint(self, running_vm: VM):
         vm = running_vm
         logging.info("Start a 'sleep' process on VM through SSH")
-        pid = vm.start_background_process('sleep 10000')
+        if vm.is_windows:
+            pid = vm.start_background_powershell('while ($true) {Start-Sleep -Seconds 10000}')
+        else:
+            pid = vm.start_background_process('sleep 10000')
+        logging.info(f"Background command PID: {pid}")
         snapshot = vm.checkpoint()
-        filepath = '/tmp/%s' % snapshot.uuid
-        vm.ssh_touch_file(filepath)
+        if vm.is_windows:
+            filepath = fr'$Env:Temp\{snapshot.uuid}'
+        else:
+            filepath = '/tmp/%s' % snapshot.uuid
+        vm.touch_file(filepath)
         snapshot.revert()
         vm.resume()
         vm.wait_for_vm_running_and_ssh_up()
         logging.info("Check file does not exist anymore")
-        vm.ssh(['test ! -f ' + filepath])
+        assert not vm.file_exists(filepath)
         logging.info("Check 'sleep' process is still running")
         assert vm.pid_exists(pid)
         logging.info("Kill background process")
-        vm.ssh(['kill ' + pid])
+        vm.kill_process(pid)
         wait_for_not(lambda: vm.pid_exists(pid), "Wait for process %s not running anymore" % pid)
         snapshot.destroy(verify=True)