start frappy server automatically, if not running yet

when restarting NICOS, the frapy servers should be (re-)started
if not running already with the correct config

commands.py

@@ -101,6 +101,7 @@ def frappy_start(**services):
             if not secnode:
                 continue
             cfginfo = secnode() or ''
+            secnode.restart(secnode.read(), False)  # restart when needed only
         else:
             if cfginfo:
                 new_cfg.append((service, secnode, cfginfo))
@@ -151,7 +152,7 @@ def set_se_list():
 def frappy(*args, main=None, stick=None, addons=None):
     """(re)start frappy server(s) with given configs and load setup if needed
 
-    - without argument: list running frappy servers
+    - without argument: list running frappy servers, restart failed frappy servers
     - frappy('<cfg>'): if available, the standard stick is added too
     - frappy(''): the stick is removed too
     - addons are not changed when not given

devices.py

@@ -31,7 +31,7 @@ import os
 from os.path import expanduser
 
 from nicos import config, session
-from nicos.core import Override, Param, Moveable, status, DeviceAlias
+from nicos.core import Override, Param, Moveable, status, DeviceAlias, SIMULATION, POLLER
 from nicos.devices.secop import SecNodeDevice
 from nicos.core import Device, anytype, listof
 from nicos.utils.comparestrings import compare
@@ -215,11 +215,17 @@ class FrappyNode(SecNodeDevice, Moveable):
     def doStart(self, value):
         if value == 'None':
             value = None
-        self.restart(value)
+        self.restart(value, True)  # frappy server will be restarted even when unchanged
 
     def doStop(self):
         """never busy"""
 
+    def doInit(self, mode):
+        if mode != SIMULATION and session.sessiontype != POLLER:
+            cfg = self.doRead()
+            self.restart(cfg, False)  # do not restart when not changed
+        super().doInit(mode)
+
     def doRead(self, maxage=0):
         if self._cfgvalue is None and self._cache:
             self._cfgvalue = self._cache.get(self, 'value')
@@ -254,7 +260,7 @@ class FrappyNode(SecNodeDevice, Moveable):
         return available_cfg
 
     def disable(self):
-        seaconn = session.devices.get('seaconn')
+        seaconn = session.devices.get('sea_%s' % self.service)
         if seaconn and seaconn._attached_secnode:
             seaconn.communicate('frappy_remove %s' % self.service)
         self._set_status(*self._status)
@@ -264,23 +270,27 @@ class FrappyNode(SecNodeDevice, Moveable):
             code, text = status.DISABLED, 'disabled'
         SecNodeDevice._set_status(self, code, text)
 
-    def restart(self, cfg=None):
+    def restart(self, cfg=None, restart=True):
         """restart frappy server
 
-        if value is not given: restart with the same config
+        :param cfg: config for frappy server, if not given, restart with the same config
-        else restart with given config
+        :param restart: when false, do not restart when already running with same cfg
         """
-        was_cfg = self._cfgvalue and ':' not in self._cfgvalue
+        if cfg is None:
-        if cfg is None:  # do restart anyway
             cfg = self._cfgvalue
-        elif cfg == self._cfgvalue:  # probably called from doStart
-            if cfg == '':
-                self.disable()
-            # do not restart in this case
-            return
-        is_cfg = cfg and ':' not in cfg
         ins = config.instrument
         info = self._service_manager.get_ins_info(ins)
+        cfginfo = {}
+        self._service_manager.get_procs(cfginfo=cfginfo)
+        running_cfg = cfginfo.get((ins, self.service), '')
+        if cfg == running_cfg:
+            if not restart:
+               return
+        else:
+            self.disable()
+        if running_cfg:
+            self._service_manager.do_stop(ins, self.service)
+        is_cfg = cfg and ':' not in cfg
         if is_cfg:
             available_cfg = self.available_cfg(self.service)
             failed = False
@@ -297,14 +307,10 @@ class FrappyNode(SecNodeDevice, Moveable):
             uri = cfg
         if uri != self.uri:
             self.uri = ''  # disconnect
-            if was_cfg:
-                self._service_manager.do_stop(ins, self.service)
         if uri:
             if is_cfg:
-                self._service_manager.do_restart(ins, self.service, cfg, self.log)
+                self._service_manager.do_start(ins, self.service, cfg, logger=self.log)
             self.uri = uri  # connect
-        else:
-            self.disable()
         self._cfgvalue = cfg
         if self._cache:
             self._cache.put(self, 'value', cfg)