Add option for wsl_shell_type, protect wsl.exe arguments if SSH shell is Powershell (#11308)

* feat(wsl): add option for wsl_shell_type, protect wsl arguments if SSH shell is Powershell

* docs(wsl): add changelog fragment

* docs(wsl): fix changelog fragment syntax, add issue link

Co-authored-by: Felix Fontein <felix@fontein.de>

* feat(wsl): improve new option documentation

Co-authored-by: Felix Fontein <felix@fontein.de>

* refactor(wsl): put integrasion test flag into a variable for convenience

* feat(wsl): rename option to wsl_remote_ssh_shell_type

* feat(wsl): escape "%" if shell is cmd, raise AnsibleError if powershell

* test(wsl): fix unit tests for wsl

- remove redundant check - moved to a separate function
- fix check for cmd escaping of "%"
- fix formatting / whitespace

* test(wsl): fix expected error message

* test(wsl): fix test - position of stop-parsing token changed

Co-authored-by: Felix Fontein <felix@fontein.de>

---------

Co-authored-by: Felix Fontein <felix@fontein.de>

changelogs/fragments/11308-wsl-shell-type.yml

@@ -0,0 +1,3 @@
+minor_changes:
+  - wsl connection plugin - add option ``wsl_remote_ssh_shell_type``. Support PowerShell in addition to cmd as the Windows
+    shell (https://github.com/ansible-collections/community.general/issues/11307, https://github.com/ansible-collections/community.general/pull/11308).

plugins/connection/wsl.py

@@ -231,6 +231,18 @@ options:
     required: true
     vars:
       - name: wsl_distribution
+  wsl_remote_ssh_shell_type:
+    description:
+      - The shell type expected in the SSH session (not inside the WSL session).
+      - See also C(ansible_shell_type).
+    type: string
+    choices:
+      - cmd
+      - powershell
+    default: cmd
+    vars:
+      - name: wsl_remote_ssh_shell_type
+    version_added: 12.2.0
   wsl_user:
     description:
       - WSL distribution user.
@@ -578,17 +590,31 @@ class Connection(ConnectionBase):
         wsl_distribution = self.get_option("wsl_distribution")
         become = self.get_option("become")
         become_user = self.get_option("become_user")
+        wsl_remote_ssh_shell_type = self.get_option("wsl_remote_ssh_shell_type")
+        is_integration_test = os.getenv("_ANSIBLE_TEST_WSL_CONNECTION_PLUGIN_WAERI5TEPHEESHA2FAE8")
+        if "%" in cmd:
+            if wsl_remote_ssh_shell_type == "powershell":
+                # there is no universal way to escape '%' here
+                # if this is raised, add a workaround to allow the specific situation (if possible)
+                raise AnsibleError("The command contains '%', cannot safely escape it for Powershell")
+            else:
+                cmd = cmd.replace("%", "^%")
         if become and become_user:
             wsl_user = become_user
         else:
             wsl_user = self.get_option("wsl_user")
-        args = ["wsl.exe", "--distribution", wsl_distribution]
+        args = ["wsl.exe"]
+        if wsl_remote_ssh_shell_type == "powershell" and not is_integration_test:
+            # Powershell stop-parsing token, treat the rest as arguments to the native command wsl.exe
+            args.append("--%")
+        args.extend(["--distribution", wsl_distribution])
         if wsl_user:
             args.extend(["--user", wsl_user])
         args.extend(["--"])
         args.extend(shlex.split(cmd))
-        if os.getenv("_ANSIBLE_TEST_WSL_CONNECTION_PLUGIN_WAERI5TEPHEESHA2FAE8"):
+        if is_integration_test:
             return shlex.join(args)
+        else:
             return list2cmdline(args)  # see https://github.com/python/cpython/blob/3.11/Lib/subprocess.py#L576
 
     def exec_command(self, cmd: str, in_data: bytes | None = None, sudoable: bool = True) -> tuple[int, bytes, bytes]:

tests/unit/plugins/connection/test_wsl.py

@@ -210,6 +210,19 @@ def test_build_wsl_command(connection):
     assert cmd == 'wsl.exe --distribution test --user test-become-user -- /bin/sh -c "ls -la"'
 
 
+def test_build_wsl_command_powershell(connection):
+    """Test wsl command building for powershell and cmd remote ssh shell"""
+    cmd = connection._build_wsl_command('/bin/sh -c "ls -la %PATH%"')
+    assert cmd == 'wsl.exe --distribution test -- /bin/sh -c "ls -la ^%PATH^%"'
+
+    connection.set_option("wsl_remote_ssh_shell_type", "powershell")
+    cmd = connection._build_wsl_command('/bin/sh -c "ls -la"')
+    assert cmd == 'wsl.exe --% --distribution test -- /bin/sh -c "ls -la"'
+
+    with pytest.raises(AnsibleError, match="The command contains '%', cannot safely escape it for Powershell"):
+        connection._build_wsl_command('/bin/sh -c "ls -la %PATH%"')
+
+
 @patch("paramiko.SSHClient")
 def test_exec_command_success(mock_ssh, connection):
     """Test successful command execution"""