Allow Forge VM runs to disable the default synced folder

Vagrantfile

@@ -3,6 +3,10 @@ if ARGV.any? { |arg| %w[up provision reload].include?(arg) } && ENV['ANSIBLE_COL
 end
 
 DOMAIN = ENV.fetch('VAGRANT_DOMAIN', 'example.com'.freeze)
+SYNCED_FOLDER = ENV.fetch('FOREMANCTL_SYNCED_FOLDER', 'enabled')
+unless %w[enabled disabled].include?(SYNCED_FOLDER)
+  abort('FOREMANCTL_SYNCED_FOLDER must be enabled or disabled')
+end
 
 # Official CentOS libvirt images include swap; Vagrant Cloud boxes do not.
 def set_centos_box_url(vm)
@@ -13,7 +17,7 @@ def set_centos_box_url(vm)
 end
 
 Vagrant.configure("2") do |config|
-  config.vm.synced_folder ".", "/vagrant"
+  config.vm.synced_folder ".", "/vagrant", disabled: SYNCED_FOLDER == 'disabled'
 
   config.vm.provision("etc_hosts", type: 'ansible') do |ansible|
     ansible.playbook = "development/playbooks/etc_host.yml"

development/playbooks/vms/metadata.obsah.yaml

@@ -12,3 +12,10 @@ variables:
   vms:
     help: Which VMs to manage, defaults to all.
     action: store
+  vm_synced_folder:
+    parameter: --synced-folder
+    help: Enable or disable /vagrant sharing. Defaults to FOREMANCTL_SYNCED_FOLDER or enabled.
+    choices:
+      - enabled
+      - disabled
+    persist: false

development/playbooks/vms/vms.yaml

@@ -3,6 +3,8 @@
   gather_facts: false
   hosts:
     - localhost
+  environment:
+    FOREMANCTL_SYNCED_FOLDER: "{{ vm_synced_folder | default(lookup('ansible.builtin.env', 'FOREMANCTL_SYNCED_FOLDER') or 'enabled', true) }}"
   tasks:
     - name: Start virtual machines
       when: vm_action == 'start'

tests/unit/vms_test.py

@@ -0,0 +1,85 @@
+import json
+import os
+import shutil
+import subprocess
+import sys
+from pathlib import Path
+
+import pytest
+
+
+@pytest.fixture
+def forge_vms(tmp_path):
+    root = Path(__file__).resolve().parents[2]
+    shutil.copy2(root / 'forge', tmp_path / 'forge')
+    shutil.copytree(root / 'development/playbooks/vms', tmp_path / 'development/playbooks/vms')
+    inventory = tmp_path / 'inventories'
+    inventory.mkdir()
+    (inventory / 'localhost').write_text(
+        f'localhost ansible_connection=local ansible_python_interpreter={sys.executable}\n'
+    )
+    scripts = tmp_path / 'development/scripts'
+    scripts.mkdir()
+    inventory_script = scripts / 'vagrant.py'
+    inventory_script.write_text('#!/bin/sh\nprintf "all:\\n  hosts: {}\\n"\n')
+    inventory_script.chmod(0o755)
+
+    # Record the Vagrant commands without allocating or changing any VMs.
+    binaries = tmp_path / 'bin'
+    binaries.mkdir()
+    vagrant = binaries / 'vagrant'
+    vagrant.write_text(
+        f'#!{sys.executable}\n'
+        'import json, os, sys\n'
+        'with open(os.environ["VAGRANT_TEST_LOG"], "a") as log:\n'
+        '    log.write(json.dumps([sys.argv[1:], os.environ.get("FOREMANCTL_SYNCED_FOLDER")]) + "\\n")\n'
+    )
+    vagrant.chmod(0o755)
+    config = tmp_path / 'ansible.cfg'
+    config.write_text('[defaults]\nretry_files_enabled = false\n')
+    log = tmp_path / 'vagrant.jsonl'
+    env = os.environ.copy()
+    env.pop('FOREMANCTL_SYNCED_FOLDER', None)
+    env.update({
+        'PATH': f'{binaries}{os.pathsep}{env["PATH"]}',
+        'ANSIBLE_CONFIG': str(config),
+        'ANSIBLE_LOCAL_TEMP': str(tmp_path / 'ansible-local'),
+        'ANSIBLE_REMOTE_TEMP': str(tmp_path / 'ansible-remote'),
+        'VAGRANT_TEST_LOG': str(log),
+    })
+    return tmp_path, env, log
+
+
+@pytest.mark.parametrize(('inherited', 'option', 'expected'), [
+    (None, None, 'enabled'),
+    ('', None, 'enabled'),
+    ('disabled', None, 'disabled'),
+    (None, 'disabled', 'disabled'),
+    ('disabled', 'enabled', 'enabled'),
+    ('enabled', 'disabled', 'disabled'),
+])
+def test_vms_shared_folder_setting_reaches_up_and_provision(forge_vms, inherited, option, expected):
+    root, env, log = forge_vms
+    if inherited is not None:
+        env['FOREMANCTL_SYNCED_FOLDER'] = inherited
+    command = ['./forge', 'vms', 'start', '--vms', 'quadlet client']
+    if option is not None:
+        command += ['--synced-folder', option]
+    result = subprocess.run(command, cwd=root, env=env, text=True, capture_output=True)
+    assert result.returncode == 0, result.stdout + result.stderr
+    assert [json.loads(line) for line in log.read_text().splitlines()] == [
+        [['up', 'quadlet', 'client'], expected],
+        [['provision', 'quadlet', 'client'], expected],
+    ]
+    assert (root / 'inventories/local_vagrant').exists()
+
+
+def test_vms_rejects_invalid_shared_folder_option(forge_vms):
+    root, env, log = forge_vms
+    result = subprocess.run(
+        ['./forge', 'vms', 'start', '--synced-folder', 'invalid'],
+        cwd=root, env=env, text=True, capture_output=True,
+    )
+    assert result.returncode != 0
+    assert 'invalid choice' in result.stderr
+    assert not log.exists()