Merge branch 'L2SS-777-add-observations-to-prometheus-exporter' into 'master'

Resolve L2SS-777 "Add observations to prometheus exporter"

Closes L2SS-777

See merge request !387

docker-compose/tango-prometheus-exporter/code/tango-prometheus-client.py

@@ -37,8 +37,33 @@ class ArchiverPolicy(object):
     def __init__(self, config: dict = None):
         self.config = config or self.EMPTY_POLICY
 
+    def device_list(self) -> list:
+        """ Retrieve the device list from TangoDB """
+        device_list = []
+        db = Database()
+        server_list = db.get_server_list()  # e.g. SDP/STAT, RECV/STAT
+        for server in server_list:
+            # https://pytango.readthedocs.io/en/stable/database.html#tango.Database.get_device_class_list
+            class_list = db.get_device_class_list(server)
+            for cls in class_list[::2]:
+                if "dserver" in cls:
+                    continue
+                device_list.append(cls.lower())
+        return device_list
+
     def devices(self) -> list:
-        return list(self.config["devices"].keys())
+        """ Filter the device list from TangoDB following the lofar2-policy file """
+        # Devices list from TangoDB
+        db_devices = self.device_list()
+        # Devices listed in policy file
+        config_devices = list(k.lower() for k in self.config["devices"].keys())
+        # Match device names fetched from DB against device names in policy file
+        devices = []
+        for config_dev in config_devices:
+            for db_dev in db_devices:
+                if fnmatch.fnmatch(db_dev, config_dev):
+                    devices.append(db_dev)
+        return devices
 
     def attribute_list(self, device_name: str, attribute_list: list) -> dict:
         """ Return the full set of archiving policy for the given device. """

docker-compose/tango-prometheus-exporter/lofar2-policy.json

@@ -29,6 +29,10 @@
         },
         "STAT/Docker/1": {
         },
+        "STAT/Observation/*":{
+        },
+        "STAT/ObservationControl/1":{
+        },
         "STAT/PSOC/1": {
         },
         "STAT/PCON/1": {