add disable option to 'master_type' minion config token

It's desirable to have a minion running without it trying to access a
master since, with engines on the minion support, the minion (via
engines) can perform tasks that don't require a master connection.

Signed-off-by: Alejandro del Castillo <alejandro.delcastillo@ni.com>

conf/minion

@@ -38,6 +38,8 @@
 # value to "str".  Failover masters can be requested by setting
 # to "failover".  MAKE SURE TO SET master_alive_interval if you are
 # using failover.
+# Setting master_type to 'disable' let's you have a running minion (with engines and
+# beacons) without a master connection
 # master_type: str
 
 # Poll interval in seconds for checking if the master is still there.  Only

salt/config/__init__.py

@@ -70,8 +70,9 @@ VALID_OPTS = {
     'master_port': int,
 
     # The behaviour of the minion when connecting to a master. Can specify 'failover',
-    # or 'func'. If 'func' is specified, the 'master' option should be set to an exec
-    # module function to run to determine the master hostname.
+    # 'disable' or 'func'. If 'func' is specified, the 'master' option should be set to an
+    # exec module function to run to determine the master hostname. If 'disable' is specified
+    # the minion will run, but will not try to connect to a master.
     'master_type': str,
 
     # Specify the format in which the master address will be specified. Can

salt/minion.py

@@ -396,8 +396,13 @@ class MinionBase(object):
         loss was detected), 'failed' should be set to True. The current
         (possibly failed) master will then be removed from the list of masters.
         '''
+        # return early if we are not connecting to a master
+        if opts['master_type'] == 'disable':
+            log.warning('Master is set to disable, skipping connection')
+            self.connected = False
+            raise tornado.gen.Return((None, None))
         # check if master_type was altered from its default
-        if opts['master_type'] != 'str' and opts['__role'] != 'syndic':
+        elif opts['master_type'] != 'str' and opts['__role'] != 'syndic':
             # check for a valid keyword
             if opts['master_type'] == 'func':
                 # split module and function and try loading the module
@@ -854,16 +859,18 @@ class Minion(MinionBase):
         This is primarily loading modules, pillars, etc. (since they need
         to know which master they connected to)
         '''
-        self.opts['master'] = master
+        if self.connected:
+            self.opts['master'] = master
+
+            # Initialize pillar before loader to make pillar accessible in modules
+            self.opts['pillar'] = yield salt.pillar.get_async_pillar(
+                self.opts,
+                self.opts['grains'],
+                self.opts['id'],
+                self.opts['environment'],
+                pillarenv=self.opts.get('pillarenv')
+            ).compile_pillar()
 
-        # Initialize pillar before loader to make pillar accessible in modules
-        self.opts['pillar'] = yield salt.pillar.get_async_pillar(
-            self.opts,
-            self.opts['grains'],
-            self.opts['id'],
-            self.opts['environment'],
-            pillarenv=self.opts.get('pillarenv')
-        ).compile_pillar()
         self.functions, self.returners, self.function_errors, self.executors = self._load_modules()
         self.serial = salt.payload.Serial(self.opts)
         self.mod_opts = self._prep_mod_opts()
@@ -895,7 +902,8 @@ class Minion(MinionBase):
 
         # add master_alive job if enabled
         if (self.opts['transport'] != 'tcp' and
-                self.opts['master_alive_interval'] > 0):
+                self.opts['master_alive_interval'] > 0 and
+                self.connected):
             self.schedule.add_job({
                 '__master_alive':
                 {
@@ -1917,7 +1925,7 @@ class Minion(MinionBase):
             periodic_cb.start()
 
         # add handler to subscriber
-        if hasattr(self, 'pub_channel'):
+        if hasattr(self, 'pub_channel') and self.pub_channel is not None:
             self.pub_channel.on_recv(self._handle_payload)
         else:
             log.error('No connection to master found. Scheduled jobs will not run.')
@@ -1976,7 +1984,7 @@ class Minion(MinionBase):
         self._running = False
         if hasattr(self, 'schedule'):
             del self.schedule
-        if hasattr(self, 'pub_channel'):
+        if hasattr(self, 'pub_channel') and self.pub_channel is not None:
             self.pub_channel.on_recv(None)
             if hasattr(self.pub_channel, 'close'):
                 self.pub_channel.close()