Airflow change port in docker compose - docker

Question

I have airflow running locally on port 8080 with the following docker-compose.yaml:
version: '3.7'
services:
postgres:
image: postgres:9.6
environment:
- POSTGRES_USER=airflow
- POSTGRES_PASSWORD=airflow
- POSTGRES_DB=airflow
logging:
options:
max-size: 10m
max-file: "3"
webserver:
image: puckel/docker-airflow:1.10.9
restart: always
depends_on:
- postgres
environment:
- LOAD_EX=y
- EXECUTOR=Local
logging:
options:
max-size: 10m
max-file: "3"
volumes:
- ./dags:/usr/local/airflow/dags
# Add this to have third party packages
- ./requirements.txt:/requirements.txt
# - ./plugins:/usr/local/airflow/plugins
ports:
- "8080:8080"
command: webserver
healthcheck:
test: ["CMD-SHELL", "[ -f /usr/local/airflow/airflow-webserver.pid ]"]
interval: 30s
timeout: 30s
retries: 3
However I need the port 8080 for another process. I tried updating to both "8080:8081" and "8081:8081" but neither worked, server would not respond. "8080:8080", however, works like a charm. What am I missing here?

Answer 1

I think you missed the only correct option. The syntax for ports is:
{host : container}
so in your case
8081:8080
should technically work. Assuming of course that airflow runs on port 8080 and has that one exposed (which it seems according to the dockerfile).

Answer 2

You could change the HTTP port on the webserver command and update the Docker port mapping like this:
on the YAML:
...
command: webserver -p 9999
ports:
- "9999:9999"
Sometimes this comes handy if you need the container to start listening directly on a specific port and avoid port mappings in scenarios where you are also changing network configurations e.g. in the YAML network_mode: host.
This basically means you can use only command: webserver -p 9999 and get rid of the ports: YAML completely.