ACU: permit scans on LAT even when Sun Avoidance is not to be enabled (…

…#586)

* ACU: full sun policy for LAT, though avoidance remains disabled

* ACU: better behavior if Sun avoidance isn't configured

* ACU: add proper return when monitor_sun exits on request

socs/agents/acu/agent.py

@@ -40,11 +40,18 @@
 }
 
 
-#: Default Sun avoidance params by platform type (enabled, policy)
+#: Default Sun avoidance params by platform type (enabled, policy). If
+#: either of escape *or* monitoring is enabled, then the full policy
+#: must be specified.
 SUN_CONFIGS = {
     'ccat': {
         'enabled': False,
-        'policy': {},
+        'policy': {
+            'exclusion_radius': 20,
+            'el_horizon': 10,
+            'min_sun_time': 1800,
+            'response_time': 7200,
+        },
     },
     'satp': {
         'enabled': True,
@@ -1713,7 +1720,7 @@ def generate_scan(self, session, params):
         ok, msg = self._check_scan_sunsafe(az_endpoint1, az_endpoint2, el_endpoint1,
                                            az_speed, az_accel)
         if ok:
-            self.log.info('Sun safety check passes: {msg}', msg=msg)
+            self.log.info('Sun safety check: {msg}', msg=msg)
         else:
             self.log.error('Sun safety check fails: {msg}', msg=msg)
             return False, 'Scan is not Sun Safe.'
@@ -2201,6 +2208,8 @@ def lookup(keys, tree):
 
             yield dsleep(1)
 
+        return True, 'monitor_sun exited cleanly.'
+
     @ocs_agent.param('reset', type=bool, default=None)
     @ocs_agent.param('enable', type=bool, default=None)
     @ocs_agent.param('temporary_disable', type=float, default=None)
@@ -2363,6 +2372,17 @@ def _leg_done(result):
         return True, "Exited."
 
     def _check_scan_sunsafe(self, az1, az2, el, v_az, a_az):
+        """This will return True if active avoidance is disabled.  If active
+        avoidance is enabled, then it will only return true if the
+        planned scan seems to currently be sun-safe.
+
+        """
+        if not self._get_sun_policy('sunsafe_moves'):
+            return True, 'Sun-safety checking is not enabled.'
+
+        if not self._get_sun_policy('map_valid'):
+            return False, 'Sun Safety Map not computed or stale; run the monitor_sun process.'
+
         # Include a bit of buffer for turn-arounds.
         az1, az2 = min(az1, az2), max(az1, az2)
         turn = v_az**2 / a_az
@@ -2378,10 +2398,7 @@ def _check_scan_sunsafe(self, az1, az2, el, v_az, a_az):
         else:
             msg = 'Scan will be unsafe in %.1f hours' % (info['sun_time'] / 3600)
 
-        if self._get_sun_policy('sunsafe_moves'):
-            return safe, msg
-        else:
-            return True, 'Sun-safety not active; %s' % msg
+        return safe, msg
 
     def _get_sunsafe_moves(self, target_az, target_el):
         """Given a target position, find a Sun-safe way to get there.  This