AIP-84 Migrate the public endpoint DAG Details to FastAPI (#42631)

* Migrate the public endpoint DAG Details to FastAPI

* Add comment for computed_field, remove unused import

* Update pendulum import path

* Re-run breeze static checks

* Add openapi-gen for DAG Details API

* Resolve review comments, test has_task_concurrency_limits

* Remove unused import

* Use lambda for aliases, re-run breeze static checks

* Remove duplicate entry

* Use simpler approach for alias

airflow/api_connexion/endpoints/dag_endpoint.py

@@ -70,6 +70,7 @@ def get_dag(
     )
 
 
+@mark_fastapi_migration_done
 @security.requires_access_dag("GET")
 @provide_session
 def get_dag_details(

airflow/api_fastapi/openapi/v1-generated.yaml

@@ -252,6 +252,57 @@ paths:
             application/json:
               schema:
                 $ref: '#/components/schemas/HTTPValidationError'
+  /public/dags/{dag_id}/details:
+    get:
+      tags:
+      - DAG
+      summary: Get Dag Details
+      description: Get details of DAG.
+      operationId: get_dag_details
+      parameters:
+      - name: dag_id
+        in: path
+        required: true
+        schema:
+          type: string
+          title: Dag Id
+      responses:
+        '200':
+          description: Successful Response
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/DAGDetailsResponse'
+        '400':
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/HTTPExceptionResponse'
+          description: Bad Request
+        '401':
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/HTTPExceptionResponse'
+          description: Unauthorized
+        '403':
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/HTTPExceptionResponse'
+          description: Forbidden
+        '404':
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/HTTPExceptionResponse'
+          description: Not Found
+        '422':
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/HTTPExceptionResponse'
+          description: Unprocessable Entity
   /public/dags/{dag_id}:
     patch:
       tags:
@@ -378,6 +429,243 @@ components:
       - total_entries
       title: DAGCollectionResponse
       description: DAG Collection serializer for responses.
+    DAGDetailsResponse:
+      properties:
+        dag_id:
+          type: string
+          title: Dag Id
+        dag_display_name:
+          type: string
+          title: Dag Display Name
+        is_paused:
+          type: boolean
+          title: Is Paused
+        is_active:
+          type: boolean
+          title: Is Active
+        last_parsed_time:
+          anyOf:
+          - type: string
+            format: date-time
+          - type: 'null'
+          title: Last Parsed Time
+        last_pickled:
+          anyOf:
+          - type: string
+            format: date-time
+          - type: 'null'
+          title: Last Pickled
+        last_expired:
+          anyOf:
+          - type: string
+            format: date-time
+          - type: 'null'
+          title: Last Expired
+        scheduler_lock:
+          anyOf:
+          - type: string
+            format: date-time
+          - type: 'null'
+          title: Scheduler Lock
+        pickle_id:
+          anyOf:
+          - type: string
+            format: date-time
+          - type: 'null'
+          title: Pickle Id
+        default_view:
+          anyOf:
+          - type: string
+          - type: 'null'
+          title: Default View
+        fileloc:
+          type: string
+          title: Fileloc
+        description:
+          anyOf:
+          - type: string
+          - type: 'null'
+          title: Description
+        timetable_summary:
+          anyOf:
+          - type: string
+          - type: 'null'
+          title: Timetable Summary
+        timetable_description:
+          anyOf:
+          - type: string
+          - type: 'null'
+          title: Timetable Description
+        tags:
+          items:
+            $ref: '#/components/schemas/DagTagPydantic'
+          type: array
+          title: Tags
+        max_active_tasks:
+          type: integer
+          title: Max Active Tasks
+        max_active_runs:
+          anyOf:
+          - type: integer
+          - type: 'null'
+          title: Max Active Runs
+        max_consecutive_failed_dag_runs:
+          type: integer
+          title: Max Consecutive Failed Dag Runs
+        has_task_concurrency_limits:
+          type: boolean
+          title: Has Task Concurrency Limits
+        has_import_errors:
+          type: boolean
+          title: Has Import Errors
+        next_dagrun:
+          anyOf:
+          - type: string
+            format: date-time
+          - type: 'null'
+          title: Next Dagrun
+        next_dagrun_data_interval_start:
+          anyOf:
+          - type: string
+            format: date-time
+          - type: 'null'
+          title: Next Dagrun Data Interval Start
+        next_dagrun_data_interval_end:
+          anyOf:
+          - type: string
+            format: date-time
+          - type: 'null'
+          title: Next Dagrun Data Interval End
+        next_dagrun_create_after:
+          anyOf:
+          - type: string
+            format: date-time
+          - type: 'null'
+          title: Next Dagrun Create After
+        owners:
+          items:
+            type: string
+          type: array
+          title: Owners
+        catchup:
+          type: boolean
+          title: Catchup
+        dag_run_timeout:
+          anyOf:
+          - type: string
+            format: duration
+          - type: 'null'
+          title: Dag Run Timeout
+        dataset_expression:
+          anyOf:
+          - type: object
+          - type: 'null'
+          title: Dataset Expression
+        doc_md:
+          anyOf:
+          - type: string
+          - type: 'null'
+          title: Doc Md
+        start_date:
+          anyOf:
+          - type: string
+            format: date-time
+          - type: 'null'
+          title: Start Date
+        end_date:
+          anyOf:
+          - type: string
+            format: date-time
+          - type: 'null'
+          title: End Date
+        is_paused_upon_creation:
+          anyOf:
+          - type: boolean
+          - type: 'null'
+          title: Is Paused Upon Creation
+        orientation:
+          type: string
+          title: Orientation
+        params:
+          anyOf:
+          - type: object
+          - type: 'null'
+          title: Params
+        render_template_as_native_obj:
+          type: boolean
+          title: Render Template As Native Obj
+        template_search_path:
+          anyOf:
+          - items:
+              type: string
+            type: array
+          - type: 'null'
+          title: Template Search Path
+        timezone:
+          anyOf:
+          - type: string
+          - type: 'null'
+          title: Timezone
+        last_parsed:
+          anyOf:
+          - type: string
+            format: date-time
+          - type: 'null'
+          title: Last Parsed
+        file_token:
+          type: string
+          title: File Token
+          description: Return file token.
+          readOnly: true
+        concurrency:
+          type: integer
+          title: Concurrency
+          description: Return max_active_tasks as concurrency.
+          readOnly: true
+      type: object
+      required:
+      - dag_id
+      - dag_display_name
+      - is_paused
+      - is_active
+      - last_parsed_time
+      - last_pickled
+      - last_expired
+      - scheduler_lock
+      - pickle_id
+      - default_view
+      - fileloc
+      - description
+      - timetable_summary
+      - timetable_description
+      - tags
+      - max_active_tasks
+      - max_active_runs
+      - max_consecutive_failed_dag_runs
+      - has_task_concurrency_limits
+      - has_import_errors
+      - next_dagrun
+      - next_dagrun_data_interval_start
+      - next_dagrun_data_interval_end
+      - next_dagrun_create_after
+      - owners
+      - catchup
+      - dag_run_timeout
+      - dataset_expression
+      - doc_md
+      - start_date
+      - end_date
+      - is_paused_upon_creation
+      - orientation
+      - params
+      - render_template_as_native_obj
+      - template_search_path
+      - timezone
+      - last_parsed
+      - file_token
+      - concurrency
+      title: DAGDetailsResponse
+      description: Specific serializer for DAG Details responses.
     DAGPatchBody:
       properties:
         is_paused:

airflow/api_fastapi/serializers/dags.py

@@ -17,12 +17,16 @@
 
 from __future__ import annotations
 
-from datetime import datetime
-from typing import Any
+from collections import abc
+from datetime import datetime, timedelta
+from typing import Any, Iterable
 
 from itsdangerous import URLSafeSerializer
+from pendulum.tz.timezone import FixedTimezone, Timezone
 from pydantic import (
+    AliasChoices,
     BaseModel,
+    Field,
     computed_field,
     field_validator,
 )
@@ -93,3 +97,56 @@ class DAGCollectionResponse(BaseModel):
 
     dags: list[DAGResponse]
     total_entries: int
+
+
+class DAGDetailsResponse(DAGResponse):
+    """Specific serializer for DAG Details responses."""
+
+    catchup: bool
+    dag_run_timeout: timedelta | None = Field(
+        validation_alias=AliasChoices("dag_run_timeout", "dagrun_timeout")
+    )
+    dataset_expression: dict | None
+    doc_md: str | None
+    start_date: datetime | None
+    end_date: datetime | None
+    is_paused_upon_creation: bool | None
+    orientation: str
+    params: abc.MutableMapping | None
+    render_template_as_native_obj: bool
+    template_search_path: Iterable[str] | None = Field(
+        validation_alias=AliasChoices("template_search_path", "template_searchpath")
+    )
+    timezone: str | None
+    last_parsed: datetime | None = Field(validation_alias=AliasChoices("last_parsed", "last_loaded"))
+
+    @field_validator("timezone", mode="before")
+    @classmethod
+    def get_timezone(cls, tz: Timezone | FixedTimezone) -> str | None:
+        """Convert timezone attribute to string representation."""
+        if tz is None:
+            return None
+        return str(tz)
+
+    @field_validator("timetable_summary", mode="before")
+    @classmethod
+    def get_timetable_summary(cls, tts: str | None) -> str | None:
+        """Validate the string representation of timetable_summary."""
+        if tts is None or tts == "None":
+            return None
+        return str(tts)
+
+    @field_validator("params", mode="before")
+    @classmethod
+    def get_params(cls, params: abc.MutableMapping | None) -> dict | None:
+        """Convert params attribute to dict representation."""
+        if params is None:
+            return None
+        return {param_name: param_val.dump() for param_name, param_val in params.items()}
+
+    # Mypy issue https://github.com/python/mypy/issues/1362
+    @computed_field  # type: ignore[misc]
+    @property
+    def concurrency(self) -> int:
+        """Return max_active_tasks as concurrency."""
+        return self.max_active_tasks