.. 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.

Running Airflow behind a reverse proxy

Airflow can be set up behind a reverse proxy, with the ability to set its endpoint with great flexibility.

For example, you can configure your reverse proxy to get:

https://lab.mycompany.com/myorg/airflow/

To do so, you need to set the following setting in your airflow.cfg::

base_url = http://my_host/myorg/airflow

Configure your reverse proxy (e.g. nginx) to pass the url and http header as it for the Airflow webserver, without any rewrite, for example::

server {
  listen 80;
  server_name lab.mycompany.com;

  location /myorg/airflow/ {
      proxy_pass http://localhost:8080;
      proxy_set_header Host $http_host;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header X-Forwarded-Proto $scheme;
      proxy_set_header Upgrade $http_upgrade;
      proxy_set_header Connection $connection_upgrade;
      proxy_redirect off;
      proxy_http_version 1.1;
  }
}

Some parts of the UI are rendered inside iframes (Auth managers security links for instance), you need to make sure that you are not setting a restricted CSP for iframe rendering such as frame-ancestors 'none'. You can set the CSP header in your reverse proxy configuration, for example::
```
add_header Content-Security-Policy "frame-ancestors 'self';";
```
Use --proxy-headers CLI flag to tell Uvicorn to respect these headers: airflow api-server --proxy-headers
If your proxy server is not on the same host (or in the same docker container) as Airflow, then you will need to set the FORWARDED_ALLOW_IPS environment variable so Uvicorn knows who to trust this header from. See Uvicorn's docs <https://www.uvicorn.org/deployment/#proxies-and-forwarded-headers>_. For the full options you can pass here. (Please note the --forwarded-allow-ips CLI option does not exist in Airflow.)
Please make sure your proxy does not enforce http-only status on the Set-Cookie headers. Airflow frontend needs to access the cookies through javascript, and a http-only flag would disturb this functionality.

Helm Chart Configuration

When deploying Airflow using the Helm chart behind a reverse proxy (e.g., nginx ingress), you need to configure the API server to respect proxy headers.

Configure the API server arguments to include the --proxy-headers flag::

apiServer:
  args: ["bash", "-c", "exec airflow api-server --proxy-headers"]

If your proxy server is not on the same host as Airflow, set the FORWARDED_ALLOW_IPS environment variable::

apiServer:
  args: ["bash", "-c", "exec airflow api-server --proxy-headers"]
  env:
    - name: FORWARDED_ALLOW_IPS
      value: "*"  # Use "*" for trusted environments, or specify proxy IP ranges for production

Additionally, configure your ingress annotations to pass the necessary headers. For nginx ingress, add these annotations::

ingress:
  apiServer:
    enabled: true
    annotations:
      nginx.ingress.kubernetes.io/proxy-http-version: "1.1"
      nginx.ingress.kubernetes.io/proxy-redirect-off: "true"
      nginx.ingress.kubernetes.io/configuration-snippet: |
        proxy_set_header Host $http_host;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;
    hosts:
      - name: airflow.example.com
        tls:
          enabled: true
          secretName: airflow-tls

Make sure to also set the base_url in your Airflow configuration::

config:
  api:
    base_url: https://airflow.example.com

.. spelling::

Uvicorn