Using Django in Docker unable to fetch rest api - django

Question

I have built the webapp using Django and also configured for Rest api. I am able to fetch the data via curl and also by python script. Issue I'm running into, when using Docker container, when user fill in the data and submit, it goes thru and ran the python function, but it stop working at when fetching the data via api and thru errors
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib/python3.6/site-packages/requests/models.py", line 897, in json
return complexjson.loads(self.text, **kwargs)
File "/usr/lib64/python3.6/json/__init__.py", line 354, in loads
return _default_decoder.decode(s)
File "/usr/lib64/python3.6/json/decoder.py", line 339, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "/usr/lib64/python3.6/json/decoder.py", line 357, in raw_decode
raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)
I'm able to curl the URL inside the container. I get the same error when shell into the container in python3.6
sh-4.2# python3.6
Python 3.6.8 (default, May 2 2019, 20:40:44)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-36)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>>
>>> import requests, json
>>> url = 'http://127.0.0.1:8001/db/data/'
>>> response = requests.get(url)
>>> parsedjson = json.loads(response.text)
ERROR SAME AS ABOVE . . .
parsedjson = response.json()
ERROR SAME AS ABOVE . . .
>>> print(response.status_code)
503
>>> exit()
sh-4.2# curl http://127.0.0.1:8001/db/data/
[{"center":{"name":"ABC"},"main":{"code":{"name":"ABC"},"subnet":"10.10.12.0",...."}]
sh-4.2#
any idea? how to fix it?
thank you for the help in advance..