无法将主机名“postgres”转换为地址：名称或服务未知 - DOCKER

Question

I have a dash app and i'm trying to host it to the port 8050 so i'm trying to create it using gunicorn and I ran my Dockerfile which contains:

FROM airflow-update
CMD gunicorn -b 0.0.0.0:8050 /py_scripts.index:server

and then i ran

docker run -p 8050:8050 airflow

and i got the error below:

sqlalchemy.exc.OperationalError: (psycopg2.OperationalError) could not translate host name "postgres" to address: Name or service not known

My docker-compose.yaml file is like this:

version: '3'
x-airflow-common:
  &airflow-common
  image: ${AIRFLOW_IMAGE_NAME:-airflow:latest}
  environment:
    &airflow-common-env
    AIRFLOW__CORE__EXECUTOR: CeleryExecutor
    AIRFLOW__CORE__SQL_ALCHEMY_CONN: postgresql+psycopg2://airflow:airflow@postgres/airflow
    AIRFLOW__CELERY__RESULT_BACKEND: db+postgresql://airflow:airflow@postgres/airflow
    AIRFLOW__CELERY__BROKER_URL: redis://:@redis:6379/0
    AIRFLOW__CORE__FERNET_KEY: ''
    AIRFLOW__CORE__DAGS_ARE_PAUSED_AT_CREATION: 'true'
    AIRFLOW__CORE__LOAD_EXAMPLES: 'true'
    AIRFLOW__API__AUTH_BACKEND: 'airflow.api.auth.backend.basic_auth'
    _PIP_ADDITIONAL_REQUIREMENTS: ${_PIP_ADDITIONAL_REQUIREMENTS:-}
  volumes:
    - ./dags:/opt/airflow/dags
    - ./logs:/opt/airflow/logs
    - ./logs:/opt/airflow/logs/pipeline-logs
    - ./py_scripts:/opt/airflow/py_scripts
    - ./data:/opt/airflow/data
    - ./dbt-redshift:/opt/airflow/dbt-redshift
    - ./output:/opt/airflow/output  
  user: "${AIRFLOW_UID:-50000}:${AIRFLOW_GID:-50000}"
  depends_on:
    redis:
      condition: service_healthy
    postgres:
      condition: service_healthy

services:
  postgres:
    image: postgres:13
    environment:
      POSTGRES_USER: airflow
      POSTGRES_PASSWORD: airflow
      POSTGRES_DB: airflow
    volumes:
      - postgres-db-volume:/var/lib/postgresql/data
    healthcheck:
      test: ["CMD", "pg_isready", "-U", "airflow"]
      interval: 5s
      retries: 5
    restart: always

  redis:
    image: redis:latest
    ports:
      - 6379:6379
    healthcheck:
      test: ["CMD", "redis-cli", "ping"]
      interval: 5s
      timeout: 30s
      retries: 50
    restart: always

  airflow-webserver:
    <<: *airflow-common
    command: webserver
    ports:
      - 8080:8080
    healthcheck:
      test: ["CMD", "curl", "--fail", "http://localhost:8080/health"]
      interval: 10s
      timeout: 10s
      retries: 5
    restart: always

  airflow-scheduler:
    <<: *airflow-common
    command: scheduler
    healthcheck:
      test: ["CMD-SHELL", 'airflow jobs check --job-type SchedulerJob --hostname "$${HOSTNAME}"']
      interval: 10s
      timeout: 10s
      retries: 5
    restart: always

  airflow-worker:
    <<: *airflow-common
    command: celery worker
    healthcheck:
      test:
        - "CMD-SHELL"
        - 'celery --app airflow.executors.celery_executor.app inspect ping -d "celery@$${HOSTNAME}"'
      interval: 10s
      timeout: 10s
      retries: 5
    restart: always

  airflow-init:
    <<: *airflow-common
    command: version
    environment:
      <<: *airflow-common-env
      _AIRFLOW_DB_UPGRADE: 'true'
      _AIRFLOW_WWW_USER_CREATE: 'true'
      _AIRFLOW_WWW_USER_USERNAME: ${_AIRFLOW_WWW_USER_USERNAME:-airflow}
      _AIRFLOW_WWW_USER_PASSWORD: ${_AIRFLOW_WWW_USER_PASSWORD:-airflow}

  flower:
    <<: *airflow-common
    command: celery flower
    ports:
      - 5555:5555
    healthcheck:
      test: ["CMD", "curl", "--fail", "http://localhost:5555/"]
      interval: 10s
      timeout: 10s
      retries: 5
    restart: always

volumes:
  postgres-db-volume:

What am i doing wrong. Should i update my docker-compose file in regards to postgres?

Answer 1

Compose creates a network named default , but your docker run command isn't attached to that network.

The best approach to this is to move this setup inside your Compose setup. If the only thing you're replacing is the command that's being run, you don't even need a custom image. This is the same pattern you have for the several other containers in this setup.

services:
  postgres: { ... }
  airflow-server:
    <<: *airflow-common
    command: gunicorn -b 0.0.0.0:8050 /py_scripts.index:server
    ports:
      - '8050:8050'
    restart: always

If you really want to run it with docker run , you need to find the network Compose creates by default and specifically attach to it. docker network ls will show it; its name will end with ..._default . Note that there's a huge amount of additional setup in the airflow-common block and docker run won't see any of this at all.

docker run --net airflow_default -p 8050:8050 airflow

Answer 2

I fixed it by adjusting @davidmaze's answer as below:

  airflow-server:
    <<: *airflow-common
    ports:
      - '8050:8050'
    restart: always
    entrypoint: gunicorn --chdir /opt/airflow/py_scripts -b 0.0.0.0:8050 index:server