fixes saltstack/salt#61708 add grains_refresh_pre_exec option for minions

changelog/61708.added

@@ -0,0 +1 @@
+Add grains_refresh_pre_exec option to allow grains to be refreshed before any operation

conf/minion

@@ -370,6 +370,12 @@
 # If the value is set to zero, this check is disabled.
 #grains_refresh_every: 1
 
+# The grains_refresh_pre_exec setting allows for a minion to check its grains
+# prior to the execution of any operation to see if they have changed and, if
+# so, to inform the master of the new grains. This operation is moderately
+# expensive, therefore care should be taken before enabling this behavior.
+#grains_refresh_pre_exec: False
+
 # Cache grains on the minion. Default is False.
 #grains_cache: False
 

doc/ref/configuration/minion.rst

@@ -934,6 +934,24 @@ A value of 10 minutes is a reasonable default.
 
     grains_refresh_every: 0
 
+.. conf_minion:: grains_refresh_pre_exec
+
+``grains_refresh_pre_exec``
+---------------------------
+
+.. versionadded:: 3005
+
+Default: ``False``
+
+The ``grains_refresh_pre_exec`` setting allows for a minion to check its grains
+prior to the execution of any operation to see if they have changed and, if
+so, to inform the master of the new grains. This operation is moderately
+expensive, therefore care should be taken before enabling this behavior.
+
+.. code-block:: yaml
+
+    grains_refresh_pre_exec: True
+
 .. conf_minion:: metadata_server_grains
 
 ``metadata_server_grains``

salt/config/__init__.py

@@ -749,6 +749,8 @@ VALID_OPTS = immutabletypes.freeze(
         "grains_blacklist": list,
         # The number of minutes between the minion refreshing its cache of grains
         "grains_refresh_every": int,
+        # Enable grains refresh prior to any operation
+        "grains_refresh_pre_exec": bool,
         # Use lspci to gather system data for grains on a minion
         "enable_lspci": bool,
         # The number of seconds for the salt client to wait for additional syndics to

salt/minion.py

@@ -1744,6 +1744,9 @@ class Minion(MinionBase):
                 self.schedule.functions = self.functions
                 self.schedule.returners = self.returners
 
+        if self.opts["grains_refresh_pre_exec"]:
+            self.opts["grains"] = salt.loader.grains(self.opts, force_refresh=True)
+
         process_count_max = self.opts.get("process_count_max")
         if process_count_max > 0:
             process_count = len(salt.utils.minion.running(self.opts))

tests/pytests/unit/test_minion.py

@@ -969,3 +969,51 @@ def test_config_cache_path_overrides():
 
     mminion = salt.minion.MasterMinion(opts)
     assert mminion.opts["cachedir"] == cachedir
+
+
+def test_minion_grains_refresh_pre_exec_false():
+    """
+    Minion does not refresh grains when grains_refresh_pre_exec is False
+    """
+    mock_opts = salt.config.DEFAULT_MINION_OPTS.copy()
+    mock_opts["multiprocessing"] = False
+    mock_opts["grains_refresh_pre_exec"] = False
+    mock_data = {"fun": "foo.bar", "jid": 123}
+    with patch("salt.loader.grains") as grainsfunc, patch(
+        "salt.minion.Minion._target", MagicMock(return_value=True)
+    ):
+        minion = salt.minion.Minion(
+            mock_opts,
+            jid_queue=None,
+            io_loop=salt.ext.tornado.ioloop.IOLoop(),
+            load_grains=False,
+        )
+        try:
+            ret = minion._handle_decoded_payload(mock_data).result()
+            grainsfunc.assert_not_called()
+        finally:
+            minion.destroy()
+
+
+def test_minion_grains_refresh_pre_exec_true():
+    """
+    Minion refreshes grains when grains_refresh_pre_exec is True
+    """
+    mock_opts = salt.config.DEFAULT_MINION_OPTS.copy()
+    mock_opts["multiprocessing"] = False
+    mock_opts["grains_refresh_pre_exec"] = True
+    mock_data = {"fun": "foo.bar", "jid": 123}
+    with patch("salt.loader.grains") as grainsfunc, patch(
+        "salt.minion.Minion._target", MagicMock(return_value=True)
+    ):
+        minion = salt.minion.Minion(
+            mock_opts,
+            jid_queue=None,
+            io_loop=salt.ext.tornado.ioloop.IOLoop(),
+            load_grains=False,
+        )
+        try:
+            ret = minion._handle_decoded_payload(mock_data).result()
+            grainsfunc.assert_called()
+        finally:
+            minion.destroy()