[BUG]: Django User ID Not Tracked When Using UUID Primary Keys

[yardensachs]

Tracer Version(s)

3.18.1

Python Version(s)

3.13.2

Pip Version(s)

pip 24.3.1

Bug Report

The Django integration fails to track user IDs when the user model uses a UUID primary key instead of an integer primary key. This is due to an overly restrictive type check in the user tracking logic introduced here.

The code currently checks if the user primary key is an integer before setting user ID tags:

dd-trace-py/ddtrace/contrib/internal/django/utils.py

Lines 331 to 334 in fdd8fed

	uid = getattr(user, "pk", None)
	if uid and isinstance(uid, int):
	span._set_tag_str("django.user.id", str(uid))
	span._set_tag_str(_user.ID, str(uid))

This means that when a Django user model uses a UUIDField as the primary key, the user ID is never tracked in spans.

Reproduction Code

1. Create a Django project with a custom user model that uses UUID as primary key:

   from django.contrib.auth.models import AbstractUser
   import uuid
   from django.db import models
   
   class User(AbstractUser):
       id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)

2. Install and configure ddtrace for Django

3. Make an authenticated request

4. Check the span tags - django.user.id will be missing

Error Logs

No response

Libraries in Use

No response

Operating System

Darwin Kernel Version 24.6.0

[wantsui]

Thank you for the very detailed report - this was a lot of great information and helped me understand how this error is happening!

I'm checking with the team involved to understand the intent of the change to determine the best approach for this issue!

[wantsui]

@yardensachs - Just a heads up I just started working on this in #15741 (currently a draft), but I won't be able to get the approvals needed until early January. Will that be alright?

[yardensachs]

@yardensachs - Just a heads up I just started working on this in #15741 (currently a draft), but I won't be able to get the approvals needed until early January. Will that be alright?

Yeah. I have a workaround for now.
@wantsui Thanks!

[wantsui]

Thanks @yardensachs ! I'll keep this issue up to date once I have any updates.