new: [updates] Update script - WiP

config/config.cfg.default

@@ -37,6 +37,7 @@ directory=logs
 dispatcher_filename=zmq_dispatcher.log
 subscriber_filename=zmq_subscriber.log
 helpers_filename=helpers.log
+update_filename=updates.log
 
 [RedisGlobal]
 host=localhost
@@ -49,6 +50,7 @@ zmq_url=tcp://localhost:50000
 [RedisLIST]
 db=3
 listName=bufferList
+dbVersion=db_version
 
 [RedisLog]
 db=0

updates.py

@@ -0,0 +1,70 @@
+import redis
+import os
+import configparser
+import logging
+
+
+configfile = os.path.join(os.path.dirname(os.path.realpath(__file__)), 'config/config.cfg')
+cfg = configparser.ConfigParser()
+cfg.read(configfile)
+serv_log = redis.StrictRedis(
+        host=cfg.get('RedisGlobal', 'host'),
+        port=cfg.getint('RedisGlobal', 'port'),
+        db=cfg.getint('RedisLog', 'db'))
+serv_redis_db = redis.StrictRedis(
+        host=cfg.get('RedisGlobal', 'host'),
+        port=cfg.getint('RedisGlobal', 'port'),
+        db=cfg.getint('RedisDB', 'db'))
+serv_list = redis.StrictRedis(
+        host=cfg.get('RedisGlobal', 'host'),
+        port=cfg.getint('RedisGlobal', 'port'),
+        db=cfg.getint('RedisLIST', 'db'))
+
+# logger
+# logDir = cfg.get('Log', 'directory')
+# logfilename = cfg.get('Log', 'update_filename')
+# logPath = os.path.join(logDir, logfilename)
+# if not os.path.exists(logDir):
+#     os.makedirs(logDir)
+# try:
+#     logging.basicConfig(filename=logPath, filemode='a', level=logging.INFO)
+# except PermissionError as error:
+#     print(error)
+#     print("Please fix the above and try again.")
+#     sys.exit(126)
+# update_logger = logging.getLogger(__name__)
+logDir = cfg.get('Log', 'directory')
+logfilename = cfg.get('Log', 'update_filename')
+logPath = os.path.join(logDir, logfilename)
+if not os.path.exists(logDir):
+    os.makedirs(logDir)
+handler = logging.FileHandler(logPath)
+formatter = logging.Formatter('%(asctime)s:%(levelname)s:%(name)s:%(message)s')
+handler.setFormatter(formatter)
+update_logger = logging.getLogger(__name__)
+update_logger.setLevel(logging.INFO)
+update_logger.addHandler(handler)
+
+
+def check_for_updates():
+    db_version = serv_redis_db.get(cfg.get('RedisDB', 'dbVersion'))
+    db_version = db_version if db_version is not None else 0
+    result = False
+
+    if db_version == 0:
+        result = apply_update_1()
+
+    if result:
+        serv_redis_db.set(cfg.get('RedisDB', 'dbVersion'), db_version+1)
+        update_logger.warning(f'Bumped dbVersion to {db_version+1}')
+    else:
+        update_logger.info('Database up-to-date')
+
+
+# Data format changed. Wipe the key.
+def apply_update_1():
+    serv_redis_db.delete('TEMP_CACHE_LIVE:Attribute')
+    log_text = 'Executed update 1. Deleted Redis key `TEMP_CACHE_LIVE:Attribute`'
+    print(log_text)
+    update_logger.info(log_text)
+    return True

zmq_dispatcher.py

@@ -15,6 +15,7 @@ import redis
 import zmq
 
 import util
+import updates
 from helpers import (contributor_helper, geo_helper, live_helper,
                      trendings_helper, users_helper)
 
@@ -256,6 +257,8 @@ def process_log(zmq_name, event):
 
 
 def main(sleeptime):
+    updates.check_for_updates()
+
     numMsg = 0
     while True:
         content = serv_list.rpop(LISTNAME)