Use a single http tag to report the server's location to front end, not two (apache#47572)

ashb · nailo2c · commit a496f109a4b3 · 2025-04-04T14:54:23.000-07:00
Previously we had both a `&lt;base href=""&gt;` tag and a `&lt;meta
name="backend-server-base-url" content=""&gt;` tag that contained almost the same
value -- one had a trailing `/` and the other didn't.

That irked me, so I updated things so the XHR requests take the URL based on
the `&lt;base&gt;` tag instead.

In order to make this change I made the following changes:
 - Instead of erroring if the URL does have a trailing `/`, the behaviour is
   now to add it if it's missing. This makes it easier kn users
 - This necessitated updating the Auth Managers to use a proper URL function,
   not string concatenation, to build the URLs

The change to `conf.set` is a side-effect/fix to allow `conf.set("api",
"base_url")` to work -- otherwise it errored with "No section found" with only
the defaults present.
diff --git a/airflow/api_fastapi/app.py b/airflow/api_fastapi/app.py
@@ -61,13 +61,12 @@ async def lifespan(app: FastAPI):
 def create_app(apps: str = "all") -> FastAPI:
     apps_list = apps.split(",") if apps else ["all"]
 
-    fastapi_base_url = conf.get("api", "base_url")
-    if fastapi_base_url.endswith("/"):
-        raise AirflowConfigException("`[api] base_url` config option cannot have a trailing slash.")
+    fastapi_base_url = conf.get("api", "base_url", fallback="")
+    if fastapi_base_url and not fastapi_base_url.endswith("/"):
+        fastapi_base_url += "/"
+        conf.set("api", "base_url", fastapi_base_url)
 
-    root_path = urlsplit(fastapi_base_url).path
-    if not root_path or root_path == "/":
-        root_path = ""
+    root_path = urlsplit(fastapi_base_url).path.removesuffix("/")
 
     app = FastAPI(
         title="Airflow API",
diff --git a/airflow/api_fastapi/auth/managers/simple/routes/login.py b/airflow/api_fastapi/auth/managers/simple/routes/login.py
@@ -17,6 +17,8 @@
 
 from __future__ import annotations
 
+from urllib.parse import urljoin
+
 from fastapi import HTTPException, status
 from starlette.responses import RedirectResponse
 
@@ -60,7 +62,7 @@ def create_token_all_admins() -> RedirectResponse:
         username="Anonymous",
         role="ADMIN",
     )
-    url = f"{conf.get('api', 'base_url')}/?token={get_auth_manager().get_jwt_token(user)}"
+    url = urljoin(conf.get("api", "base_url"), f"?token={get_auth_manager().get_jwt_token(user)}")
     return RedirectResponse(url=url)
 
 
diff --git a/airflow/configuration.py b/airflow/configuration.py
@@ -1289,6 +1289,11 @@ def set(self, section: str, option: str, value: str | None = None) -> None:
         """
         section = section.lower()
         option = option.lower()
+        defaults = self.configuration_description or {}
+        if not self.has_section(section) and section in defaults:
+            # Trying to set a key in a section that exists in default, but not in the user config;
+            # automatically create it
+            self.add_section(section)
         super().set(section, option, value)
 
     def remove_option(self, section: str, option: str, remove_default: bool = True):
diff --git a/airflow/ui/dev/index.html b/airflow/ui/dev/index.html
@@ -3,7 +3,7 @@
 <html lang="en" style="height: 100%">
   <head>
     <meta charset="UTF-8" />
-    <meta name="backend-server-base-url" content="{{ backend_server_base_url }}" />
+    <base href="{{ backend_server_base_url }}" />
     <link rel="icon" type="image/png" href="http://localhost:5173/public/pin_32.png" />
     <script type="module" src="http://localhost:5173/@vite/client"></script>
     <script type="module">
diff --git a/airflow/ui/index.html b/airflow/ui/index.html
@@ -2,10 +2,9 @@
 <html lang="en" style="height: 100%">
   <head>
     <meta charset="UTF-8" />
-    <base href="{{ backend_server_base_url }}/" />
+    <base href="{{ backend_server_base_url }}" />
     <link rel="icon" type="image/png" href="/static/pin_32.png" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <meta name="backend-server-base-url" content="{{ backend_server_base_url }}" />
     <title>Airflow 3.0</title>
   </head>
   <body style="height: 100%">
diff --git a/airflow/ui/src/queryClient.ts b/airflow/ui/src/queryClient.ts
@@ -21,7 +21,10 @@ import { QueryClient } from "@tanstack/react-query";
 import { OpenAPI } from "openapi/requests/core/OpenAPI";
 
 // Dynamically set the base URL for XHR requests based on the meta tag.
-OpenAPI.BASE = document.querySelector("meta[name='backend-server-base-url']")?.getAttribute("content") ?? "";
+OpenAPI.BASE = document.querySelector("head>base")?.getAttribute("href") ?? "";
+if (OpenAPI.BASE.endsWith("/")) {
+  OpenAPI.BASE = OpenAPI.BASE.slice(0, -1);
+}
 
 export const queryClient = new QueryClient({
   defaultOptions: {
diff --git a/airflow/utils/helpers.py b/airflow/utils/helpers.py
@@ -25,6 +25,7 @@
 from datetime import datetime
 from functools import cache, reduce
 from typing import TYPE_CHECKING, Any, Callable, TypeVar, cast
+from urllib.parse import urljoin
 
 from lazy_object_proxy import Proxy
 
@@ -259,7 +260,7 @@ def build_airflow_dagrun_url(dag_id: str, run_id: str) -> str:
     http://localhost:8080/dags/hi/runs/manual__2025-02-23T18:27:39.051358+00:00_RZa1at4Q
     """
     baseurl = conf.get("api", "base_url")
-    return f"{baseurl}/dags/{dag_id}/runs/{run_id}"
+    return urljoin(baseurl, f"dags/{dag_id}/runs/{run_id}")
 
 
 # The 'template' argument is typed as Any because the jinja2.Template is too
diff --git a/providers/amazon/src/airflow/providers/amazon/aws/auth_manager/aws_auth_manager.py b/providers/amazon/src/airflow/providers/amazon/aws/auth_manager/aws_auth_manager.py
@@ -21,6 +21,7 @@
 from collections.abc import Sequence
 from functools import cached_property
 from typing import TYPE_CHECKING, Any, cast
+from urllib.parse import urljoin
 
 from fastapi import FastAPI
 
@@ -321,7 +322,7 @@ def _has_access_to_dag(request: IsAuthorizedRequest):
         return {dag_id for dag_id in dag_ids if _has_access_to_dag(requests[dag_id][method])}
 
     def get_url_login(self, **kwargs) -> str:
-        return f"{self.apiserver_endpoint}/auth/login"
+        return urljoin(self.apiserver_endpoint, "auth/login")
 
     @staticmethod
     def get_cli_commands() -> list[CLICommand]:
diff --git a/providers/amazon/src/airflow/providers/amazon/aws/auth_manager/router/login.py b/providers/amazon/src/airflow/providers/amazon/aws/auth_manager/router/login.py
@@ -19,6 +19,7 @@
 
 import logging
 from typing import Any
+from urllib.parse import urljoin
 
 import anyio
 from fastapi import HTTPException, Request
@@ -79,7 +80,7 @@ def login_callback(request: Request):
         username=saml_auth.get_nameid(),
         email=attributes["email"][0] if "email" in attributes else None,
     )
-    url = f"{conf.get('api', 'base_url')}/?token={get_auth_manager().get_jwt_token(user)}"
+    url = urljoin(conf.get("api", "base_url"), f"?token={get_auth_manager().get_jwt_token(user)}")
     return RedirectResponse(url=url, status_code=303)
 
 
diff --git a/providers/fab/src/airflow/providers/fab/auth_manager/fab_auth_manager.py b/providers/fab/src/airflow/providers/fab/auth_manager/fab_auth_manager.py
@@ -21,6 +21,7 @@
 from functools import cached_property
 from pathlib import Path
 from typing import TYPE_CHECKING, Any
+from urllib.parse import urljoin
 
 import packaging.version
 from connexion import FlaskApi
@@ -409,7 +410,7 @@ def security_manager(self) -> FabAirflowSecurityManagerOverride:
 
     def get_url_login(self, **kwargs) -> str:
         """Return the login page url."""
-        return f"{self.apiserver_endpoint}/auth/login/"
+        return urljoin(self.apiserver_endpoint, "auth/login/")
 
     def get_url_logout(self):
         """Return the logout page url."""
diff --git a/providers/fab/src/airflow/providers/fab/www/views.py b/providers/fab/src/airflow/providers/fab/www/views.py
@@ -70,7 +70,7 @@ class FabIndexView(IndexView):
     def index(self):
         if g.user is not None and g.user.is_authenticated:
             token = get_auth_manager().get_jwt_token(g.user)
-            return redirect(f"{conf.get('api', 'base_url')}/?token={token}", code=302)
+            return redirect(urljoin(conf.get("api", "base_url"), f"?token={token}"), code=302)
         else:
             return super().index()
 
