add CACHE_REDIS_HOST as env variable to config.py

[Daniel-Boluda]

This is usefull for hosts not being "redis", in my env i have instance "jellyplist-redis" so i get this error, that can be fixed with this approach:

connection.connect()

File "/usr/local/lib/python3.12/site-packages/redis/connection.py", line 363, in connect
raise ConnectionError(self._error_message(e))
redis.exceptions.ConnectionError: Error -2 connecting to redis:6379. Name or service not known.
[2025-01-26 14:30:00,011][ trace.py: 267 - _log_error() ] ERROR - Task app.tasks.update_all_playlists_track_status[4c9fc9f3-a5aa-48ef-a6bc-bfd38e4bb7c4] raised unexpected: ConnectionError('Error -2 connecting to redis:6379. Name or service not known.')
Traceback (most recent call last):
File "/usr/local/lib/python3.12/site-packages/redis/connection.py", line 357, in connect
sock = self.retry.call_with_retry(
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/site-packages/redis/retry.py", line 62, in call_with_retry
return do()
^^^^
File "/usr/local/lib/python3.12/site-packages/redis/connection.py", line 358, in
lambda: self._connect(), lambda error: self.disconnect(error)
^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/site-packages/redis/connection.py", line 698, in _connect
for res in socket.getaddrinfo(
^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/socket.py", line 976, in getaddrinfo
for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
socket.gaierror: [Errno -2] Name or service not known

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/usr/local/lib/python3.12/site-packages/celery/app/trace.py", line 453, in trace_task
R = retval = fun(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/site-packages/celery/app/trace.py", line 736, in protected_call
return self.run(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^
File "/jellyplist/app/tasks.py", line 33, in update_all_playlists_track_status
if task_manager.acquire_lock(lock_key, expiration=600):
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/jellyplist/app/tasks.py", line 696, in acquire_lock
return redis_client.set(lock_name, "locked", ex=expiration, nx=True)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/site-packages/redis/commands/core.py", line 2335, in set
return self.execute_command("SET", *pieces, **options)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/site-packages/redis/client.py", line 559, in execute_command
return self._execute_command(*args, **options)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/site-packages/redis/client.py", line 565, in _execute_command
conn = self.connection or pool.get_connection(command_name, **options)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/site-packages/redis/connection.py", line 1422, in get_connection
connection.connect()
File "/usr/local/lib/python3.12/site-packages/redis/connection.py", line 363, in connect
raise ConnectionError(self._error_message(e))
redis.exceptions.ConnectionError: Error -2 connecting to redis:6379. Name or service not known.
[2025-01-26 14:35:00,008][ trace.py: 267 - _log_error() ] ERROR - Task app.tasks.update_all_playlists_track_status[4b0a6552-7a18-46a2-bc19-b87d4557dab4] raised unexpected: ConnectionError('Error -2 connecting to redis:6379. Name or service not known.')
Traceback (most recent call last):
File "/usr/local/lib/python3.12/site-packages/redis/connection.py", line 357, in connect
sock = self.retry.call_with_retry(
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/site-packages/redis/retry.py", line 62, in call_with_retry
return do()
^^^^
File "/usr/local/lib/python3.12/site-packages/redis/connection.py", line 358, in
lambda: self._connect(), lambda error: self.disconnect(error)
^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/site-packages/redis/connection.py", line 698, in _connect
for res in socket.getaddrinfo(
^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/socket.py", line 976, in getaddrinfo
for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
socket.gaierror: [Errno -2] Name or service not known