Merge pull request #17240 from mgwilliams/ext_processes

Ext processes

doc/topics/ext_processes/index.rst

@@ -0,0 +1,59 @@
+.. _ext_processes:
+
+===============================
+Running Custom Master Processes
+===============================
+
+In addition to the processes that the Salt Master automatically spawns,
+it is possible to configure it to start additional custom processes.
+
+This is useful if a dedicated process is needed that should run throughout
+the life of the Salt Master. For periodic independent tasks, a
+:doc:`scheduled runner <../jobs/schedule.rst>` may be more appropriate.
+
+Processes started in this way will be restarted if they die and will be
+killed when the Salt Master is shut down.
+
+
+Example Configureation
+======================
+
+Processes are declared in the master config file with the `ext_processes`
+option. Processes will be started in the order they are declared.
+
+.. code-block:: yaml
+
+    ext_processes:
+      - mymodule.TestProcess
+      - mymodule.AnotherProcess
+
+
+Example Process Class
+=====================
+
+.. code-block:: python
+
+    # Import python libs
+    import time
+    import logging
+    from multiprocessing import Process
+    
+    # Import Salt libs
+    from salt.utils.event import SaltEvent
+    
+    
+    log = logging.getLogger(__name__)
+    
+    
+    class TestProcess(Process):
+        def __init__(self, opts):
+            Process.__init__(self)
+            self.opts = opts
+    
+        def run(self):
+            self.event = SaltEvent('master', self.opts['sock_dir'])
+            i = 0
+
+            while True:
+                self.event.fire_event({'iteration': i}, 'ext_processes/test{0}')
+                time.sleep(60)

salt/master.py

@@ -348,6 +348,19 @@ class Master(SMaster):
             log.info('Creating master reactor process')
             process_manager.add_process(salt.utils.event.Reactor, args=(self.opts,))
 
+        ext_procs = self.opts.get('ext_processes', [])
+        for proc in ext_procs:
+            log.info('Creating ext_processes process: {0}'.format(proc))
+            try:
+                mod = '.'.join(proc.split('.')[:-1])
+                cls = proc.split('.')[-1]
+                _tmp = __import__(mod, globals(), locals(), [cls], -1)
+                cls = _tmp.Test
+                process_manager.add_process(cls, args=(self.opts,))
+            except Exception as e:
+                log.warning(('Error creating ext_processes '
+                           'process: {0}').format(proc))
+
         if HAS_HALITE and 'halite' in self.opts:
             log.info('Creating master halite process')
             process_manager.add_process(Halite, args=(self.opts['halite'],))