Allow Users to disable SwaggerUI via configuration (#28354)

Due to potential issues, we want to give teams the opportunity to 
disable the swaggerUI. This can now be done via the configuration 
key: webserver.enable_swagger_ui. For backwards compatibility, 
this has been set to true by default, but for teams willing to disable 
this it can be set to false.

airflow/config_templates/config.yml

@@ -1513,6 +1513,13 @@
       type: string
       example: "dagrun_cleared,failed"
       default: ~
+    - name: enable_swagger_ui
+      description: |
+        Boolean for running SwaggerUI in the webserver.
+      version_added: 2.6.0
+      type: boolean
+      example: ~
+      default: "True"
     - name: run_internal_api
       description: |
         Boolean for running Internal API in the webserver.

airflow/config_templates/default_airflow.cfg

@@ -771,6 +771,9 @@ audit_view_excluded_events = gantt,landing_times,tries,duration,calendar,graph,g
 # Example: audit_view_included_events = dagrun_cleared,failed
 # audit_view_included_events =
 
+# Boolean for running SwaggerUI in the webserver.
+enable_swagger_ui = True
+
 # Boolean for running Internal API in the webserver.
 run_internal_api = False
 

airflow/www/extensions/init_appbuilder_links.py

@@ -16,6 +16,7 @@
 # under the License.
 from __future__ import annotations
 
+from airflow.configuration import conf
 from airflow.utils.docs import get_docs_url
 
 
@@ -36,12 +37,14 @@ def init_appbuilder_links(app):
     appbuilder.add_link(
         name="Documentation", label="GitHub Repo", href="https://github.com/apache/airflow", category="Docs"
     )
-    appbuilder.add_link(
-        name="Documentation",
-        label="REST API Reference (Swagger UI)",
-        href="/api/v1./api/v1_swagger_ui_index",
-        category="Docs",
-    )
+
+    if conf.getboolean("webserver", "enable_swagger_ui", fallback=True):
+        appbuilder.add_link(
+            name="Documentation",
+            label="REST API Reference (Swagger UI)",
+            href="/api/v1./api/v1_swagger_ui_index",
+            category="Docs",
+        )
     appbuilder.add_link(
         name="Documentation", label="REST API Reference (Redoc)", href="RedocView.redoc", category="Docs"
     )

airflow/www/extensions/init_views.py

@@ -208,7 +208,8 @@ def _handle_method_not_allowed(ex):
             return views.method_not_allowed(ex)
 
     spec_dir = path.join(ROOT_APP_DIR, "api_connexion", "openapi")
-    connexion_app = App(__name__, specification_dir=spec_dir, skip_error_handlers=True)
+    options = {"swagger_ui": conf.getboolean("webserver", "enable_swagger_ui", fallback=True)}
+    connexion_app = App(__name__, specification_dir=spec_dir, skip_error_handlers=True, options=options)
     connexion_app.app = app
     api_bp = connexion_app.add_api(
         specification="v1.yaml", base_path=base_path, validate_responses=True, strict_validation=True
@@ -227,7 +228,8 @@ def init_api_internal(app: Flask) -> None:
     base_path = "/internal_api/v1"
 
     spec_dir = path.join(ROOT_APP_DIR, "api_internal", "openapi")
-    internal_app = App(__name__, specification_dir=spec_dir, skip_error_handlers=True)
+    options = {"swagger_ui": conf.getboolean("webserver", "enable_swagger_ui", fallback=True)}
+    internal_app = App(__name__, specification_dir=spec_dir, skip_error_handlers=True, options=options)
     internal_app.app = app
     api_bp = internal_app.add_api(
         specification="internal_api_v1.yaml",