L2SS-550: Install archiver json config along with package, slightly simplify...

L2SS-550: Install archiver json config along with package, slightly simplify its use by merging Selector into Archiver, and do not apply by default in the constructor, making all actions explicit.

tangostationcontrol/setup.cfg

@@ -57,3 +57,7 @@ console_scripts =
     l2ss-random-data = tangostationcontrol.test.devices.random_data:main
     l2ss-snmp = tangostationcontrol.examples.snmp.snmp:main
     l2ss-version = tangostationcontrol.common.lofar_version:main
+
+[options.package_data]
+* = *.json
+

tangostationcontrol/tangostationcontrol/toolkit/archiver.py

@@ -6,6 +6,7 @@ from tango import DeviceProxy, AttributeProxy, DevState, DevFailed
 
 import time
 import json, os
+import pkg_resources
 
 logger = logging.getLogger()
 
@@ -64,7 +65,7 @@ class Archiver():
     dev_polling_time = None
     dev_archive_time = None
 
-    def __init__(self, selector_filename:str = None, cm_name: str = 'archiving/hdbppts/confmanager01', context: str = 'RUN'):
+    def __init__(self, cm_name: str = 'archiving/hdbppts/confmanager01', context: str = 'RUN'):
         self.cm_name = cm_name
         self.cm = DeviceProxy(cm_name)
         try: 
@@ -74,11 +75,6 @@ class Archiver():
             raise Exception(f"Connection failed with Configuration Manager {cm_name}") from e
         self.es_list = [es_name for es_name in self.get_subscribers(from_db=False)]
         self.cm.write_attribute('Context',context)    # Set default Context Archiving for all the subscribers
-        self.selector = Selector() if selector_filename is None else Selector(selector_filename)  # Create selector for customized strategies
-        try:
-            self.apply_selector()
-        except Exception as e:
-            raise Exception("Error in selecting configuration. Archiving framework will not be updated.") from e
     
     def get_db_config(self, device_name:str) -> dict:
         """
@@ -131,11 +127,15 @@ class Archiver():
             min_es = min(load_dict,key=load_dict.get)
             return min_es
 
-    def apply_selector(self):
+    def get_configuration(self, resource: str = 'lofar2') -> dict:
+        """ Read an archiver configuration from one of the preinstalled resources in archiver_config. """
+        resource = pkg_resources.resource_stream(__name__, f'archiver_config/{resource}.json')
+        return json.load(resource)
+
+    def apply_configuration(self, config_dict: dict):
         """
-        Apply the customized strategy defined by the selector
+        Apply the customized strategy defined by the given archiver configuration.
         """
-        config_dict = self.selector.get_dict()
         # Set global development env variables
         var_dict = config_dict.get('global_variables')
         self.dev_polling_time = int(var_dict.get('development_polling_time'))
@@ -170,7 +170,6 @@ class Archiver():
                     logger.warning(f"Device {device} not defined in TangoDB")
                 else:
                     raise Exception from e                              
-        return env_dict
     
     def add_event_subscriber(self, es_name:str=None):
         """
@@ -445,24 +444,3 @@ class AttributeFormatException(Exception):
     def __init__(self, message="Wrong Tango attribute format! Try: domain/family/member/attribute (e.g. STAT/RECV/1/temperature)"):
         self.message = message
         super().__init__(self.message)
-
-class Selector():
-    """
-    The Selector class implements operations on select customized retrieval strategies
-    """
-
-    def __init__(self, filename='lofar2.json'):
-        self.filename = filename
-    
-    def get_dict(self):
-        """
-        Create a dictionary from the JSON file
-        """
-        try:
-            filepath = os.path.join(os.path.dirname(__file__),'archiver_config',self.filename)
-            f = open(filepath)
-            data = json.load(f)
-            f.close()
-        except FileNotFoundError as e:
-            raise
-        return data