Update mlflow.set_tracking_uri to support pathlib.Path (#5820)

[cacharle]

What changes are proposed in this pull request?

Fixes #5820

How is this patch tested?

Test if set_tracking_uri convert a path to a URI string.

Does this PR change the documentation?

• No. You can skip the rest of this section.
• Yes. Make sure the changed pages / sections render correctly by following the steps below.

1. Check the status of the ci/circleci: build_doc check. If it's successful, proceed to the
   next step, otherwise fix it.
2. Click Details on the right to open the job page of CircleCI.
3. Click the Artifacts tab.
4. Click docs/build/html/index.html.
5. Find the changed pages / sections and make sure they render correctly.

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.

mlflow.set_tracking_uri now supports pathlib.Path.

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

Components

• area/artifacts: Artifact stores and artifact logging
• area/build: Build and test infrastructure for MLflow
• area/docs: MLflow documentation pages
• area/examples: Example code
• area/model-registry: Model Registry service, APIs, and the fluent client calls for Model Registry
• area/models: MLmodel format, model serialization/deserialization, flavors
• area/projects: MLproject format, project running backends
• area/scoring: MLflow Model server, model deployment tools, Spark UDFs
• area/server-infra: MLflow Tracking server backend
• area/tracking: Tracking Service, tracking client APIs, autologging

Interface

• area/uiux: Front-end, user experience, plotting, JavaScript, JavaScript dev server
• area/docker: Docker use across MLflow's components, such as MLflow Projects and MLflow Models
• area/sqlalchemy: Use of SQLAlchemy in the Tracking Service or Model Registry
• area/windows: Windows support

Language

• language/r: R APIs and clients
• language/java: Java APIs and clients
• language/new: Proposals for new client languages

Integrations

• integrations/azure: Azure and Azure ML integrations
• integrations/sagemaker: SageMaker integrations
• integrations/databricks: Databricks integrations

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

• rn/breaking-change - The PR will be mentioned in the "Breaking Changes" section
• 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/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

[github-actions]

@cacharle Thanks for the contribution! The DCO check failed. Please sign off your commits by following the instructions here: https://github.com/mlflow/mlflow/runs/6320105654. See https://github.com/mlflow/mlflow/blob/master/CONTRIBUTING.rst#sign-your-work for more details.

[dbczumar]

@cacharle LGTM once docs errors (https://github.com/mlflow/mlflow/pull/5824/files#r867309500) are addressed. Thanks so much for your contribution!

[harupy]

@cacharle I think we need to add pathlib.Path in nitpick_ignore to fix the build_doc failure:

mlflow/docs/source/conf.py

Line 316 in 5f956fb

nitpick_ignore = [

[harupy]

Can you also fix the DCO check failure?

[harupy]

LGTM!

[harupy]

This test fails on windows when absolute is False:

D:\a\mlflow\mlflow\mlflow\tracking\_tracking_service\utils.py:75: in set_tracking_uri
    uri = uri.resolve().as_uri()
        uri        = WindowsPath('foo/bar')
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = WindowsPath('foo/bar')

    def as_uri(self):
        """Return the path as a 'file' URI."""
        if not self.is_absolute():
>           raise ValueError("relative path can't be expressed as a file URI")
E           ValueError: relative path can't be expressed as a file URI

[cacharle]

Weird, I call resolve just before as_uri so the path should be absolute.

[harupy]

@cacharle Found https://bugs.python.org/issue38671

[harupy]

I'm reading https://stackoverflow.com/a/44569249 now.

[harupy]

Can we call mkdir before resolve?

uri.mkdir(exist_ok=True)
uri = uri.resolve().as_uri()

[cacharle]

I did some test on windows with python3.7 and absolute seemed to work.

I didn't knew absolute was deprecated tho

absolute is more solid now apparently python/cpython#26153

[cacharle]

Okay, I checked and mlflow create the directory anyway when we call start_run.

So mkdir should be fine.

[harupy]

@cacharle Does this work on windows?

(Path.cwd() / uri).resolve()

Test on Linux

# absolute path
>>> (Path.cwd() / Path("foo").resolve()).resolve()
PosixPath('/home/haru/Desktop/repositories/mlflow/foo')
# relative path
>>> (Path.cwd() / Path("foo")).resolve()
PosixPath('/home/haru/Desktop/repositories/mlflow/foo')

[cacharle]

Works on windows aswell

[harupy]

Awesome, let's use this to avoid creating a direcotry. Looks like you already pushed a commit.

[harupy]

@cacharle Thanks for the update! Triggered the CI checks.

[cacharle]

Well, the Path.cwd() / uri worked on my coworker's machine (I don't have access to a windows machine to run the tests on), not sure what's happening here. We could just tried to call uri.absolute() instead of uri.resolve().

Or uri.absolute().resolve() so .absolute() for the weird windows stuff and resolve for a clean uri.

[harupy]

The test failure report indicates Path("foo/bar").resolve().as_uri() failed:

__________________ test_set_tracking_uri_with_path[relative] __________________

tmp_path = WindowsPath('C:/Users/runneradmin/AppData/Local/Temp/pytest-of-runneradmin/pytest-0/test_set_tracking_uri_with_pat1')
monkeypatch = <_pytest.monkeypatch.MonkeyPatch object at 0x000001874D42C6C8>
absolute = False

    @pytest.mark.parametrize("absolute", [True, False], ids=["absolute", "relative"])
    def test_set_tracking_uri_with_path(tmp_path, monkeypatch, absolute):
        monkeypatch.chdir(tmp_path)
        path = Path("foo/bar")
        if absolute:
            path = tmp_path / path
        with mock.patch("mlflow.tracking._tracking_service.utils._tracking_uri", None):
            set_tracking_uri(path)
>           assert get_tracking_uri() == path.resolve().as_uri()

absolute   = False
monkeypatch = <_pytest.monkeypatch.MonkeyPatch object at 0x000001874D42C6C8>
path       = WindowsPath('foo/bar')
tmp_path   = WindowsPath('C:/Users/runneradmin/AppData/Local/Temp/pytest-of-runneradmin/pytest-0/test_set_tracking_uri_with_pat1')

D:\a\mlflow\mlflow\tests\tracking\_tracking_service\test_utils.py:374: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = WindowsPath('foo/bar')

    def as_uri(self):
        """Return the path as a 'file' URI."""
        if not self.is_absolute():
>           raise ValueError("relative path can't be expressed as a file URI")
E           ValueError: relative path can't be expressed as a file URI

self       = WindowsPath('foo/bar')

c:\hostedtoolcache\windows\python\3.7.9\x64\lib\pathlib.py:739: ValueError

I think we can just do:

assert get_tracking_uri() == (tmp_path / path).resolve().as_uri()

[harupy]

LGTM!