504- Gateway timeout only in django function

Question

I have a very mind-boggling problem and my team has struggled to solve it. We do have it narrowed down but not 100%.

Introduction

We are trying to implement LTI in a Django app with the Vue frontend. To fetch the token from the URL the backend makes a POST request to the URL with data and should receive a token or error if it's expired or invalid.

Design

---

Browser ---- POST REQUEST --> view function on Server (Django) --- POST REQUEST --> Auth URL

Problem

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The post request that Django view makes times out with 504 Gateway Timeout. This could be normal if the server takes a lot of time. However, increasing the time did not help and checked Auth URL with POSTMAN it worked fine and was not down.

What I have tried

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We decided to debug or diagnose this issue that why a code block works in a function when it is called through a shell but not when it is called by a POST request does not.

1. Eliminated the front end and used POSTMAN to send a POST request to my Django server -- timeout on the Auth URL
2. Called the same function using Django shell -- worked
3. Copied the code into a separate python file outside Django -- worked
4. Used same virtual env for all above

What it appears to be

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When a POST function is called and another post request is made inside it then it times out. Please note: If I make a POST request in the same situation with invalid data (say missing grant_type) then it does not time out.

---

Code Block

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auth_request = {
    "grant_type": "client_credentials",
    "client_assertion_type": "urn:ietf:params:oauth:client-assertion-type:jwt-bearer",
    "client_assertion": "eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsImtpZCI6IlJVbzNJWWlSR0ZDYUhNNEg0S2lid095enAtRU9KWlAweXkwd0g3bk5VOEEifQ.eyJpc3MiOiI2NjkxNmZmYy03YjE5LTQ0MWEtYjE5Zi0yOGQxMzVmYjZjOWYiLCJzdWIiOiI2NjkxNmZmYy03YjE5LTQ0MWEtYjE5Zi0yOGQxMzVmYjZjOWYiLCJhdWQiOiJodHRwczovL2RldmVsb3Blci5ibGFja2JvYXJkLmNvbS9hcGkvdjEvZ2F0ZXdheS9vYXV0aDIvand0dG9rZW4iLCJpYXQiOjE2NTMyODcyNzMsImV4cCI6MTY1MzI4NzMzOCwianRpIjoibHRpLXNlcnZpY2UtdG9rZW4tMDQyZTZhNjctNDA2My00YmQ1LWI2NmQtNTM4YjU2ZTllM2Q1In0.8Jaou965cPTCFv-7yP9iIlH8mMgQjAi0AR2li0KwCcRuHsRZ_1OpbE83bZ06RMXhbjA4crRqTI4zMi8aNfq16Mkg4lXoPj8JiJW7q8b_ZQ1rLZvIojmabehYjpyscHRitFPLibfTYF2mCjUyHqwPgnFRLNrHIVuSvM0BiK56PuYK6SiiSjxu2U3bmJqOHNW2mqx2YYfkaXx2u7ru6CKTiL3KBGzFPYjCUwwWNBdbz4R0g0aHK_l-hhA3oi_pCDZOyqdnyCmGAj5SpZbuZOqrZbQBrqPoEFtXdNDPpHGGwW7IUbbmCtsmE2NqQiYt6snmK-1pbxsLxE0mXrpDqASh4A",
    "scope": "https://purl.imsglobal.org/spec/lti-nrps/scope/contextmembership.readonly",
}
response = requests.post(
    "https://developer.blackboard.com/api/v1/gateway/oauth2/jwttoken",
    data=auth_request,
)
response = response.json()
print(response)