cli: retry grabbing the lock

This helps when the timer job is running in the background and a cli
command happens to collide with it. The timer job is usually over
quickly, so retrying several times with a small sleep time should be
sufficient.

uaclient/cli/__init__.py

@@ -180,7 +180,7 @@ def assert_lock_file(lock_holder=None):
     def wrapper(f):
         @wraps(f)
         def new_f(*args, cfg, **kwargs):
-            with lock.SingleAttemptLock(cfg=cfg, lock_holder=lock_holder):
+            with lock.SpinLock(cfg=cfg, lock_holder=lock_holder, sleep_time=1):
                 retval = f(*args, cfg=cfg, **kwargs)
             return retval
 

uaclient/cli/tests/test_cli_attach.py

@@ -176,10 +176,12 @@ def test_already_attached(self, capsys, FakeConfig, event):
         }
         assert expected == json.loads(capsys.readouterr()[0])
 
+    @mock.patch("time.sleep")
     @mock.patch("uaclient.system.subp")
     def test_lock_file_exists(
         self,
         m_subp,
+        m_sleep,
         capsys,
         FakeConfig,
         event,
@@ -189,7 +191,7 @@ def test_lock_file_exists(
         cfg.write_cache("lock", "123:pro disable")
         with pytest.raises(LockHeldError) as exc_info:
             action_attach(mock.MagicMock(), cfg=cfg)
-        assert [mock.call(["ps", "123"])] == m_subp.call_args_list
+        assert [mock.call(["ps", "123"])] * 12 == m_subp.call_args_list
         assert (
             "Unable to perform: pro attach.\n"
             "Operation in progress: pro disable (pid:123)"

uaclient/cli/tests/test_cli_detach.py

@@ -103,10 +103,12 @@ def test_unattached_error_message(
         }
         assert expected == json.loads(capsys.readouterr()[0])
 
+    @mock.patch("time.sleep")
     @mock.patch("uaclient.system.subp")
     def test_lock_file_exists(
         self,
         m_subp,
+        m_sleep,
         m_prompt,
         FakeConfig,
         capsys,
@@ -118,7 +120,7 @@ def test_lock_file_exists(
         cfg.write_cache("lock", "123:pro enable")
         with pytest.raises(exceptions.LockHeldError) as err:
             action_detach(args, cfg=cfg)
-        assert [mock.call(["ps", "123"])] == m_subp.call_args_list
+        assert [mock.call(["ps", "123"])] * 12 == m_subp.call_args_list
         expected_error_msg = messages.E_LOCK_HELD_ERROR.format(
             lock_request="pro detach", lock_holder="pro enable", pid="123"
         )

uaclient/cli/tests/test_cli_disable.py

@@ -532,10 +532,12 @@ def test_unattached_error_message(
             expected["errors"][0]["additional_info"] = expected_info
         assert expected == json.loads(fake_stdout.getvalue())
 
+    @mock.patch("time.sleep")
     @mock.patch("uaclient.system.subp")
     def test_lock_file_exists(
         self,
         m_subp,
+        m_sleep,
         FakeConfig,
         event,
     ):
@@ -549,7 +551,7 @@ def test_lock_file_exists(
         with pytest.raises(exceptions.LockHeldError) as err:
             args.service = ["esm-infra"]
             action_disable(args, cfg)
-        assert [mock.call(["ps", "123"])] == m_subp.call_args_list
+        assert [mock.call(["ps", "123"])] * 12 == m_subp.call_args_list
         assert expected_error.msg == err.value.msg
 
         args.assume_yes = True

uaclient/cli/tests/test_cli_enable.py

@@ -131,10 +131,12 @@ def test_non_root_users_are_rejected(
         }
         assert expected == json.loads(capsys.readouterr()[0])
 
+    @mock.patch("time.sleep")
     @mock.patch("uaclient.system.subp")
     def test_lock_file_exists(
         self,
         m_subp,
+        m_sleep,
         _refresh,
         capsys,
         event,
@@ -147,7 +149,7 @@ def test_lock_file_exists(
 
         with pytest.raises(exceptions.LockHeldError) as err:
             action_enable(args, cfg=cfg)
-        assert [mock.call(["ps", "123"])] == m_subp.call_args_list
+        assert [mock.call(["ps", "123"])] * 12 == m_subp.call_args_list
 
         expected_message = messages.E_LOCK_HELD_ERROR.format(
             lock_request="pro enable", lock_holder="pro disable", pid="123"

uaclient/cli/tests/test_cli_refresh.py

@@ -75,14 +75,15 @@ def test_not_attached_errors(
         else:
             action_refresh(mock.MagicMock(target=target), cfg=cfg)
 
+    @mock.patch("time.sleep")
     @mock.patch("uaclient.system.subp")
-    def test_lock_file_exists(self, m_subp, FakeConfig):
+    def test_lock_file_exists(self, m_subp, m_sleep, FakeConfig):
         """Check inability to refresh if operation holds lock file."""
         cfg = FakeConfig().for_attached_machine()
         cfg.write_cache("lock", "123:pro disable")
         with pytest.raises(exceptions.LockHeldError) as err:
             action_refresh(mock.MagicMock(), cfg=cfg)
-        assert [mock.call(["ps", "123"])] == m_subp.call_args_list
+        assert [mock.call(["ps", "123"])] * 12 == m_subp.call_args_list
         assert (
             "Unable to perform: pro refresh.\n"
             "Operation in progress: pro disable (pid:123)"