Summary

mongo-orchestration fails when trying to start MongoDB 4.0 deployments. The root cause seems to be that the latest version of pymongo dropped support for MongoDB 4.0.

E.g. error log:

   File "drivers-evergreen-tools/.local/uv-tool/drivers-orchestration/lib/python3.13/site-packages/mongo_orchestration/common.py", line 130, in connected
     client.admin.command('isMaster')
     ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^
   ...
   File "drivers-evergreen-tools/.local/uv-tool/drivers-orchestration/lib/python3.13/site-packages/pymongo/topology_description.py", line 168, in check_compatible
     raise ConfigurationError(self._incompatible_err)
 pymongo.errors.ConfigurationError: Server at localhost:27017 reports wire version 7, but this version of PyMongo requires at least 8 (MongoDB 4.2).

Motivation

Who is the affected end user?

Drivers devs who still need to test on MongoDB 4.0

How does this affect the end user?

The team's Evergreen CI scripts break.

How likely is it that this problem or use case will occur?

All MongoDB 4.0 tasks fail.

If the problem does occur, what are the consequences and how severe are they?

Teams are unable to run their Evergreen CI tasks for MongoDB 4.0

Is this issue urgent?

It may block teams from releasing if they depend on passing tests for supported MongoDB versions.

Is this ticket required by a downstream team?

No.

Is this ticket only for tests?

Yes.

Acceptance Criteria

• Update mongo-orchestration to use a version of pymongo that supports MongoDB 4.0
  • See a previous PR that fixed support for MongoDB 3.6 in mongo-orchestration.
• Should we pin the pymongo version to 4.11 so we don't have to repeat this fix every time pymongo drops support for a MongoDB version?