Model Registry docs (mlflow#2021)

* Model Registry OSS docs

Co-Authored-By: Siddharth Murching <smurching@users.noreply.github.com>
Co-Authored-By: Stephanie Bodoff <stbof@users.noreply.github.com>

docs/source/index.rst

@@ -26,6 +26,7 @@ Get started using the :ref:`quickstart` or by reading about the :ref:`key concep
     tracking
     projects
     models
+    model-registry
     cli
     search-syntax
     python_api/index

docs/source/model-registry.rst

@@ -0,0 +1,123 @@
+.. _registry:
+
+=====================
+MLflow Model Registry
+=====================
+
+The MLflow Model Registry component is a centralized model store, set of APIs, and UI, to
+collaboratively manage the full lifecycle of an MLflow Model. It provides model lineage (which
+MLflow experiment and run produced the model), model versioning, stage transitions (for example from
+staging to production), and annotations.
+
+.. contents:: Table of Contents
+  :local:
+  :depth: 1
+
+Concepts
+========
+
+The MLflow Model Registry is a standalone component that introduces several concepts that
+describe the full lifecycle of an MLflow Model.
+
+Model
+    An MLflow Model logged with one of the model flavor’s ``log_model`` methods.
+
+Registered Model
+    An MLflow Model registered with the MLflow Model Registry. A registered model has a unique name, contains versions, and other metadata.
+
+Model Version
+    Each registered model can have one or many versions. When a new model is added to the Model Registry, it is added as version 1. Each new model registered to the same model name increments the version number.
+
+Model Stage
+    Each model version can be assigned one or many stages. MLflow provides predefined stages for
+    common use-cases such as *Staging* and *Production*.
+
+
+Adding an MLflow Model to the Model Registry
+============================================
+
+Before a model can be added to the Model Registry you must log it using the ``log_model`` methods
+of the corresponding model flavors. Once a model has been logged, you can add it to the registry
+either through a UI workflow or through APIs.
+
+UI Workflow
+-----------
+
+From the MLflow Runs detail page, select a logged MLflow Model in the **Artifacts** section. Click the **Register Model** button.
+
+.. figure:: _static/images/oss_registry_1_register.png
+
+In the **Model Name** field, if you are adding a new model, specify a unique name to identify the model. If you are registering a new version to an existing model, pick the existing model name from the dropdown.
+
+.. figure:: _static/images/oss_registry_2_dialog.png
+
+Once the model is added to the Model Registry you can:
+
+- Navigate to the **Registered Models** page and view the model properties.
+
+  .. figure:: _static/images/oss_registry_3_overview.png
+
+- Go to the **Artifacts** section of the run detail page, click the model, and then click the model version at the top right to view the version you just created.
+
+  .. figure:: _static/images/oss_registry_3b_version.png
+
+Each model has an overview page that shows the active versions. Click a version to navigate to the version detail page.
+
+.. figure:: _static/images/oss_registry_4_version.png
+
+On the version detail page you can see model version details and the current stage of the model
+version. If you click on the stage in the top right, you can transition the model
+version to one of the other valid stages.
+
+.. figure:: _static/images/oss_registry_5_transition.png
+
+
+API Workflow
+------------
+
+Once a model is logged using ``log_model`` you can add it to the registry, referencing the model by its URI.
+
+Call the ``register_model`` API to add it to the registry.
+
+.. code-block:: py
+
+   mlflow.register_model("runs:/e148278107274..832/artifacts/model",
+                         "EmailMarketingCampaign")
+
+Alternatively, you can pass ``registered_model_name`` to ``log_model`` to log the model under the
+specified registered model.
+
+.. code-block:: py
+
+   mlflow.tensorflow.log_model(tf_saved_model_dir=saved_estimator_path,
+                               tf_meta_graph_tags=[tag_constants.SERVING],
+                               tf_signature_def_key="predict",
+                               artifact_path="model",
+                               registered_model_name="EmailMarketingCampaign")
+
+.. note:: If the registered model does not already exist, the registry will create one before creating a new model version.
+
+With the ``get_model_version_details`` API you can confirm that the model has successfully been
+registered.
+
+.. code-block:: py
+
+   client = mlflow.tracking.MlflowClient()
+   client.get_model_version_details(name = "EmailMarketingCampaign",
+                                    version = 12)
+
+You can ask for the latest version of each registered model by a particular stage.
+
+.. code-block:: py
+
+   client.get_latest_versions(name = "EmailMarketingCampaign",
+                              stages = ["Staging"])
+
+Newly-registered model versions are added to the registry with stage **None**. You can update its
+stage.
+
+.. code-block:: py
+
+   client.update_model_version(name = "EmailMarketingCampaign",
+                               version = 12
+                               stage = "Production")

docs/source/python_api/mlflow.entities.rst

@@ -4,3 +4,7 @@ mlflow.entities
 .. automodule:: mlflow.entities
     :members:
     :undoc-members:
+
+.. automodule:: mlflow.entities.model_registry
+    :members:
+    :undoc-members: