Add default passphrase support by BenWilson2 · Pull Request #19360 · mlflow/mlflow

BenWilson2 · 2025-12-12T21:17:49Z

🛠 DevTools 🛠

Install mlflow from this PR

# mlflow
pip install git+https://github.com/mlflow/mlflow.git@refs/pull/19360/merge
# mlflow-skinny
pip install git+https://github.com/mlflow/mlflow.git@refs/pull/19360/merge#subdirectory=libs/skinny

For Databricks, use the following command:

%sh curl -LsSf https://raw.githubusercontent.com/mlflow/mlflow/HEAD/dev/install-skinny.sh | sh -s pull/19360/merge

Related Issues/PRs

#xxx

What changes are proposed in this pull request?

This PR adds a default KEK (Key Encryption Key) passphrase for the gateway secrets feature and exposes this information via an ajax server-side-only API endpoint so the frontend can warn users when they're using the default passphrase.
This allows for a non-disruptive getting started scenario or for a single-user to utilize AI Gateway if high security is not a major concern. The addition of the flag to the endpoint will be used for notifications in the UI (fetched during main landing page load).

GET /ajax-api/3.0/mlflow/secrets/config

  {
    "secrets_available": true/false,
    "using_default_passphrase": true|false
  }

How is this PR tested?

Existing unit/integration tests
New unit/integration tests
Manual tests

Does this PR require documentation update?

Release Notes

Is this a user-facing change?

No. You can skip the rest of this section.
Yes. Give a description of this change to be included in the release notes for MLflow users.

What component(s), interfaces, languages, and integrations does this PR affect?

Components

How should the PR be classified in the release notes? Choose one:

rn/none - No description will be included. The PR will be mentioned only by the PR number in the "Small Bugfixes and Documentation Updates" section
rn/breaking-change - The PR will be mentioned in the "Breaking Changes" section
rn/feature - A new user-facing feature worth mentioning in the release notes
rn/bug-fix - A user-facing bug fix worth mentioning in the release notes
rn/documentation - A user-facing documentation change worth mentioning in the release notes

Should this PR be included in the next patch release?

Yes should be selected for bug fixes, documentation updates, and other small changes. No should be selected for new features and larger changes. If you're unsure about the release classification of this PR, leave this unchecked to let the maintainers decide.

What is a minor/patch release?

Minor release: a release that increments the second part of the version number (e.g., 1.2.0 -> 1.3.0).
Bug fixes, doc updates and new features usually go into minor releases.
Patch release: a release that increments the third part of the version number (e.g., 1.2.0 -> 1.2.1).
Bug fixes and doc updates usually go into patch releases.

Yes (this PR will be cherry-picked and included in the next patch release)
No (this PR will be included in the next minor release)

Signed-off-by: Ben Wilson <benjamin.wilson@databricks.com>

Copilot

Pull request overview

This PR adds default KEK (Key Encryption Key) passphrase support for the MLflow gateway secrets feature, enabling a non-disruptive getting started experience for development and single-user scenarios. The default passphrase is automatically used when MLFLOW_CRYPTO_KEK_PASSPHRASE is not set, and a new API endpoint exposes whether the server is using the default passphrase to allow the UI to display appropriate warnings.

Key changes:

Introduces a default passphrase constant for development/testing environments with comprehensive security warnings
Adds a using_default_passphrase property to KEKManager to track passphrase source
Exposes passphrase status via new /ajax-api/3.0/mlflow/secrets/config endpoint returning JSON with secrets_available and using_default_passphrase flags

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
mlflow/utils/crypto.py	Implements default passphrase fallback in KEKManager, adds using_default_passphrase property, and improves decryption error messages to help users diagnose passphrase mismatches
mlflow/server/handlers.py	Adds new _get_secrets_config endpoint handler and registers it in gateway endpoints list
tests/utils/test_crypto.py	Updates tests to verify default passphrase behavior instead of expecting exceptions, adds test for custom passphrase flag
tests/tracking/test_rest_tracking.py	Adds integration tests for the new secrets config endpoint covering both custom and default passphrase scenarios

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

github-actions · 2025-12-12T21:27:04Z

Documentation preview for d626d6e is available at:

https://pr-19360--mlflow-docs-preview.netlify.app/docs/latest/

More info

Ignore this comment if this PR does not change the documentation.
The preview is updated when a new commit is pushed to this PR.
This comment was created by this workflow run.
The documentation was built by this workflow run.

TomeHirata · 2025-12-15T03:11:15Z

mlflow/utils/crypto.py

+            passphrase = DEFAULT_KEK_PASSPHRASE
+            _logger.warning(
+                "MLFLOW_CRYPTO_KEK_PASSPHRASE not set. Using default passphrase for "
+                "secrets encryption. This is acceptable for development/testing but "


Shall we explicitly tell what kind of case is risky? Here I think development/testing refers to localhost tracking server and production refer to remove tracking server (or tracking server with public hostname), correct? Even for users who share a remote tracking server among multiple team members for agent development, we want them to set MLFLOW_CRYPTO_KEK_PASSPHRASE

Great call out! I'll add additional details to specify where this is a security flaw and where it doesn't really matter.

TomeHirata · 2025-12-15T03:12:50Z

tests/tracking/test_rest_tracking.py

+
+
+def test_get_secrets_config_with_custom_passphrase(mlflow_client_with_secrets):
+    import requests


requests is imported on the top of this file

TomeHirata · 2025-12-15T03:13:10Z

tests/tracking/test_rest_tracking.py

+    import requests
+
+    from mlflow.server import handlers
+    from mlflow.server.fastapi_app import app
+    from mlflow.server.handlers import initialize_backend_stores
+    from mlflow.store.tracking.sqlalchemy_store import SqlAlchemyStore
+
+    from tests.tracking.integration_test_utils import ServerThread, get_safe_port
+


can we import packages on the module level where possible?

TomeHirata

Overall looks good to me, left some comments on warning message and test style

Signed-off-by: Ben Wilson <benjamin.wilson@databricks.com>

Signed-off-by: Ben Wilson <39283302+BenWilson2@users.noreply.github.com>

BenWilson2 · 2025-12-15T18:02:35Z

GenAI test failure is being addressed in #19407; windows failure is unrelated.

Signed-off-by: Ben Wilson <benjamin.wilson@databricks.com> Signed-off-by: Ben Wilson <39283302+BenWilson2@users.noreply.github.com>

Add default passphrase support

8b6e0e9

Signed-off-by: Ben Wilson <benjamin.wilson@databricks.com>

Copilot AI review requested due to automatic review settings December 12, 2025 21:17

github-actions bot added v3.7.1 area/tracking Tracking service, tracking client APIs, autologging rn/feature Mention under Features in Changelogs. labels Dec 12, 2025

Copilot started reviewing on behalf of BenWilson2 December 12, 2025 21:18 View session

Copilot AI reviewed Dec 12, 2025

View reviewed changes

TomeHirata reviewed Dec 15, 2025

View reviewed changes

TomeHirata approved these changes Dec 15, 2025

View reviewed changes

github-actions bot assigned TomeHirata Dec 15, 2025

BenWilson2 and others added 2 commits December 15, 2025 11:36

move imports and improve warning

6263234

Signed-off-by: Ben Wilson <benjamin.wilson@databricks.com>

Merge branch 'master' into default-passphrase

d626d6e

Signed-off-by: Ben Wilson <39283302+BenWilson2@users.noreply.github.com>

BenWilson2 merged commit 43d8f6e into mlflow:master Dec 15, 2025
45 of 49 checks passed

BenWilson2 deleted the default-passphrase branch December 15, 2025 18:02

WeichenXu123 pushed a commit to WeichenXu123/mlflow that referenced this pull request Dec 19, 2025

Add default passphrase support (mlflow#19360)

73b795d

Signed-off-by: Ben Wilson <benjamin.wilson@databricks.com> Signed-off-by: Ben Wilson <39283302+BenWilson2@users.noreply.github.com>

WeichenXu123 pushed a commit that referenced this pull request Dec 19, 2025

Add default passphrase support (#19360)

beb606b

Signed-off-by: Ben Wilson <benjamin.wilson@databricks.com> Signed-off-by: Ben Wilson <39283302+BenWilson2@users.noreply.github.com>

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Add default passphrase support#19360

Add default passphrase support#19360
BenWilson2 merged 3 commits intomlflow:masterfrom
BenWilson2:default-passphrase

BenWilson2 commented Dec 12, 2025 •

edited by github-actions bot

Loading

Uh oh!

Copilot AI left a comment

Uh oh!

github-actions bot commented Dec 12, 2025 •

edited

Loading

Uh oh!

TomeHirata Dec 15, 2025 •

edited

Loading

Uh oh!

BenWilson2 Dec 15, 2025

Uh oh!

TomeHirata Dec 15, 2025

Uh oh!

TomeHirata Dec 15, 2025

Uh oh!

TomeHirata left a comment

Uh oh!

BenWilson2 commented Dec 15, 2025

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants



		def test_get_secrets_config_with_custom_passphrase(mlflow_client_with_secrets):
		import requests

Conversation

BenWilson2 commented Dec 12, 2025 • edited by github-actions bot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Install mlflow from this PR

Related Issues/PRs

What changes are proposed in this pull request?

How is this PR tested?

Does this PR require documentation update?

Release Notes

Is this a user-facing change?

What component(s), interfaces, languages, and integrations does this PR affect?

How should the PR be classified in the release notes? Choose one:

Should this PR be included in the next patch release?

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

github-actions bot commented Dec 12, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

TomeHirata Dec 15, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

BenWilson2 Dec 15, 2025

Choose a reason for hiding this comment

Uh oh!

TomeHirata Dec 15, 2025

Choose a reason for hiding this comment

Uh oh!

TomeHirata Dec 15, 2025

Choose a reason for hiding this comment

Uh oh!

TomeHirata left a comment

Choose a reason for hiding this comment

Uh oh!

BenWilson2 commented Dec 15, 2025

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

BenWilson2 commented Dec 12, 2025 •

edited by github-actions bot

Loading

github-actions bot commented Dec 12, 2025 •

edited

Loading

TomeHirata Dec 15, 2025 •

edited

Loading