Add service endpoint to provide hook meta data for UI

airflow/api_fastapi/core_api/datamodels/connections.py

@@ -18,6 +18,8 @@
 from __future__ import annotations
 
 import json
+from collections import abc
+from typing import Annotated
 
 from pydantic import Field, field_validator
 from pydantic_core.core_schema import ValidationInfo
@@ -75,6 +77,52 @@ class ConnectionTestResponse(BaseModel):
     message: str
 
 
+class ConnectionHookFieldBehavior(BaseModel):
+    """A class to store the behavior of each standard field of a Hook."""
+
+    hidden: Annotated[
+        bool,
+        Field(description="Flag if the form field should be hidden."),
+    ] = False
+    title: Annotated[
+        str | None,
+        Field(
+            description="Label / title for the field that should be displayed, if re-labelling is needed. Use `None` to display standard title."
+        ),
+    ] = None
+    placeholder: Annotated[
+        str | None,
+        Field(description="Placeholder text that should be populated to the form."),
+    ] = None
+
+
+class StandardHookFields(BaseModel):
+    """Standard fields of a Hook that a form will render."""
+
+    description: ConnectionHookFieldBehavior | None
+    url_schema: ConnectionHookFieldBehavior | None
+    host: ConnectionHookFieldBehavior | None
+    port: ConnectionHookFieldBehavior | None
+    login: ConnectionHookFieldBehavior | None
+    password: ConnectionHookFieldBehavior | None
+
+
+class ConnectionHookMetaData(BaseModel):
+    """
+    Response model for Hook information == Connection type meta data.
+
+    It is used to transfer providers information loaded by providers_manager such that
+    the API server/Web UI can use this data to render connection form UI.
+    """
+
+    connection_type: str | None
+    hook_class_name: str | None
+    default_conn_name: str | None
+    hook_name: str
+    standard_fields: StandardHookFields | None
+    extra_fields: abc.MutableMapping | None
+
+
 # Request Models
 class ConnectionBody(StrictBaseModel):
     """Connection Serializer for requests body."""

airflow/api_fastapi/core_api/openapi/v1-generated.yaml

@@ -58,6 +58,26 @@ paths:
                 $ref: '#/components/schemas/HTTPExceptionResponse'
       security:
       - OAuth2PasswordBearer: []
+  /ui/connections/hook_meta:
+    get:
+      tags:
+      - Connection
+      summary: Hook Meta Data
+      description: Retrieve information about available connection types (hook classes)
+        and their parameters.
+      operationId: hook_meta_data
+      responses:
+        '200':
+          description: Successful Response
+          content:
+            application/json:
+              schema:
+                items:
+                  $ref: '#/components/schemas/ConnectionHookMetaData'
+                type: array
+                title: Response Hook Meta Data
+      security:
+      - OAuth2PasswordBearer: []
   /ui/dags/recent_dag_runs:
     get:
       tags:
@@ -8117,6 +8137,74 @@ components:
       - total_entries
       title: ConnectionCollectionResponse
       description: Connection Collection serializer for responses.
+    ConnectionHookFieldBehavior:
+      properties:
+        hidden:
+          type: boolean
+          title: Hidden
+          description: Flag if the form field should be hidden.
+          default: false
+        title:
+          anyOf:
+          - type: string
+          - type: 'null'
+          title: Title
+          description: Label / title for the field that should be displayed, if re-labelling
+            is needed. Use `None` to display standard title.
+        placeholder:
+          anyOf:
+          - type: string
+          - type: 'null'
+          title: Placeholder
+          description: Placeholder text that should be populated to the form.
+      type: object
+      title: ConnectionHookFieldBehavior
+      description: A class to store the behavior of each standard field of a Hook.
+    ConnectionHookMetaData:
+      properties:
+        connection_type:
+          anyOf:
+          - type: string
+          - type: 'null'
+          title: Connection Type
+        hook_class_name:
+          anyOf:
+          - type: string
+          - type: 'null'
+          title: Hook Class Name
+        default_conn_name:
+          anyOf:
+          - type: string
+          - type: 'null'
+          title: Default Conn Name
+        hook_name:
+          type: string
+          title: Hook Name
+        standard_fields:
+          anyOf:
+          - $ref: '#/components/schemas/StandardHookFields'
+          - type: 'null'
+        extra_fields:
+          anyOf:
+          - type: object
+          - type: 'null'
+          title: Extra Fields
+      type: object
+      required:
+      - connection_type
+      - hook_class_name
+      - default_conn_name
+      - hook_name
+      - standard_fields
+      - extra_fields
+      title: ConnectionHookMetaData
+      description: 'Response model for Hook information == Connection type meta data.
+
+
+        It is used to transfer providers information loaded by providers_manager such
+        that
+
+        the API server/Web UI can use this data to render connection form UI.'
     ConnectionResponse:
       properties:
         connection_id:
@@ -10218,6 +10306,42 @@ components:
       - latest_scheduler_heartbeat
       title: SchedulerInfoResponse
       description: Scheduler info serializer for responses.
+    StandardHookFields:
+      properties:
+        description:
+          anyOf:
+          - $ref: '#/components/schemas/ConnectionHookFieldBehavior'
+          - type: 'null'
+        url_schema:
+          anyOf:
+          - $ref: '#/components/schemas/ConnectionHookFieldBehavior'
+          - type: 'null'
+        host:
+          anyOf:
+          - $ref: '#/components/schemas/ConnectionHookFieldBehavior'
+          - type: 'null'
+        port:
+          anyOf:
+          - $ref: '#/components/schemas/ConnectionHookFieldBehavior'
+          - type: 'null'
+        login:
+          anyOf:
+          - $ref: '#/components/schemas/ConnectionHookFieldBehavior'
+          - type: 'null'
+        password:
+          anyOf:
+          - $ref: '#/components/schemas/ConnectionHookFieldBehavior'
+          - type: 'null'
+      type: object
+      required:
+      - description
+      - url_schema
+      - host
+      - port
+      - login
+      - password
+      title: StandardHookFields
+      description: Standard fields of a Hook that a form will render.
     StructureDataResponse:
       properties:
         edges:

airflow/api_fastapi/core_api/routes/ui/__init__.py

@@ -20,6 +20,7 @@
 from airflow.api_fastapi.core_api.routes.ui.assets import assets_router
 from airflow.api_fastapi.core_api.routes.ui.backfills import backfills_router
 from airflow.api_fastapi.core_api.routes.ui.config import config_router
+from airflow.api_fastapi.core_api.routes.ui.connections import connections_router
 from airflow.api_fastapi.core_api.routes.ui.dags import dags_router
 from airflow.api_fastapi.core_api.routes.ui.dashboard import dashboard_router
 from airflow.api_fastapi.core_api.routes.ui.dependencies import dependencies_router
@@ -30,6 +31,7 @@
 
 ui_router.include_router(assets_router)
 ui_router.include_router(config_router)
+ui_router.include_router(connections_router)
 ui_router.include_router(dags_router)
 ui_router.include_router(dependencies_router)
 ui_router.include_router(dashboard_router)

airflow/api_fastapi/core_api/routes/ui/connections.py

@@ -0,0 +1,40 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+from __future__ import annotations
+
+from fastapi import Depends
+
+from airflow.api_fastapi.common.router import AirflowRouter
+from airflow.api_fastapi.core_api.datamodels.connections import ConnectionHookMetaData
+from airflow.api_fastapi.core_api.security import requires_access_connection
+from airflow.api_fastapi.core_api.services.ui.connections import HookMetaService
+
+connections_router = AirflowRouter(tags=["Connection"], prefix="/connections")
+
+
+@connections_router.get(
+    "/hook_meta",
+    dependencies=[Depends(requires_access_connection(method="GET"))],
+)
+def hook_meta_data() -> list[ConnectionHookMetaData]:
+    """Retrieve information about available connection types (hook classes) and their parameters."""
+    # Note:
+    # This endpoint is implemented to serve the connections form in the UI. It is building on providers
+    # manager and hooks being loaded in the API server. Target should be that the API server reads the
+    # information from a database table to un-bundle the dependency for provider package install from
+    # the API server.
+    return HookMetaService.hook_meta_data()