iptables: support wait parameter

lib/ansible/modules/system/iptables.py

@@ -335,6 +335,12 @@
     type: str
     choices: [ ACCEPT, DROP, QUEUE, RETURN ]
     version_added: "2.2"
+  wait:
+    description:
+      - Wait N seconds for the xtables lock to prevent multiple instances of
+        the program from running concurrently.
+    type: str
+    version_added: "2.10"
 '''
 
 EXAMPLES = r'''
@@ -458,9 +464,15 @@
 
 import re
 
+from distutils.version import LooseVersion
+
 from ansible.module_utils.basic import AnsibleModule
 
 
+IPTABLES_WAIT_SUPPORT_ADDED = '1.4.20'
+
+IPTABLES_WAIT_WITH_SECONDS_SUPPORT_ADDED = '1.6.0'
+
 BINS = dict(
     ipv4='iptables',
     ipv6='ip6tables',
@@ -512,8 +524,14 @@ def append_jump(rule, param, jump):
         rule.extend(['-j', jump])
 
 
+def append_wait(rule, param, flag):
+    if param:
+        rule.extend([flag, param])
+
+
 def construct_rule(params):
     rule = []
+    append_wait(rule, params['wait'], '-w')
     append_param(rule, params['protocol'], '-p', False)
     append_param(rule, params['source'], '-s', False)
     append_param(rule, params['destination'], '-d', False)
@@ -630,6 +648,12 @@ def get_chain_policy(iptables_path, module, params):
     return None
 
 
+def get_iptables_version(iptables_path, module):
+    cmd = [iptables_path, '--version']
+    rc, out, _ = module.run_command(cmd, check_rc=True)
+    return out.split('v')[1].rstrip('\n')
+
+
 def main():
     module = AnsibleModule(
         supports_check_mode=True,
@@ -641,6 +665,7 @@ def main():
             chain=dict(type='str'),
             rule_num=dict(type='str'),
             protocol=dict(type='str'),
+            wait=dict(type='str'),
             source=dict(type='str'),
             to_source=dict(type='str'),
             destination=dict(type='str'),
@@ -717,6 +742,15 @@ def main():
         elif module.params['jump'] != 'LOG':
             module.fail_json(msg="Logging options can only be used with the LOG jump target.")
 
+    # Check if wait option is supported
+    iptables_version = LooseVersion(get_iptables_version(iptables_path, module))
+
+    if iptables_version >= LooseVersion(IPTABLES_WAIT_SUPPORT_ADDED):
+        if iptables_version < LooseVersion(IPTABLES_WAIT_WITH_SECONDS_SUPPORT_ADDED):
+            module.params['wait'] = ''
+    else:
+        module.params['wait'] = None
+
     # Flush the table
     if args['flush'] is True:
         args['changed'] = True

test/units/modules/system/test_iptables.py

@@ -8,13 +8,20 @@ def get_bin_path(*args, **kwargs):
     return "/sbin/iptables"
 
 
+def get_iptables_version(iptables_path, module):
+    return "1.8.2"
+
+
 class TestIptables(ModuleTestCase):
 
     def setUp(self):
         super(TestIptables, self).setUp()
         self.mock_get_bin_path = patch.object(basic.AnsibleModule, 'get_bin_path', get_bin_path)
         self.mock_get_bin_path.start()
         self.addCleanup(self.mock_get_bin_path.stop)  # ensure that the patching is 'undone'
+        self.mock_get_iptables_version = patch.object(iptables, 'get_iptables_version', get_iptables_version)
+        self.mock_get_iptables_version.start()
+        self.addCleanup(self.mock_get_iptables_version.stop)  # ensure that the patching is 'undone'
 
     def test_without_required_parameters(self):
         """Failure must occurs when all parameters are missing"""
@@ -828,3 +835,41 @@ def test_iprange(self):
             '--dst-range',
             '10.0.0.50-10.0.0.100'
         ])
+
+    def test_insert_rule_with_wait(self):
+        """Test flush without parameters"""
+        set_module_args({
+            'chain': 'OUTPUT',
+            'source': '1.2.3.4/32',
+            'destination': '7.8.9.10/42',
+            'jump': 'ACCEPT',
+            'action': 'insert',
+            'wait': '10'
+        })
+
+        commands_results = [
+            (0, '', ''),
+        ]
+
+        with patch.object(basic.AnsibleModule, 'run_command') as run_command:
+            run_command.side_effect = commands_results
+            with self.assertRaises(AnsibleExitJson) as result:
+                iptables.main()
+                self.assertTrue(result.exception.args[0]['changed'])
+
+        self.assertEqual(run_command.call_count, 1)
+        self.assertEqual(run_command.call_args_list[0][0][0], [
+            '/sbin/iptables',
+            '-t',
+            'filter',
+            '-C',
+            'OUTPUT',
+            '-w',
+            '10',
+            '-s',
+            '1.2.3.4/32',
+            '-d',
+            '7.8.9.10/42',
+            '-j',
+            'ACCEPT'
+        ])