可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试):
问题:
I have a dockerized setup running a Django app within which I use Celery tasks. Celery uses Redis as the broker.
Versioning:
- Docker version 17.09.0-ce, build afdb6d4
- docker-compose version 1.15.0, build e12f3b9
- Django==1.9.6
- django-celery-beat==1.0.1
- celery==4.1.0
- celery[redis]
- redis==2.10.5
Problem:
My celery workers appear to be unable to connect to the redis container located at localhost:6379. I am able to telnet into the redis server on the specified port. I am able to verify redis-server is running on the container.
When I manually connect to the Celery docker instance and attempt to create a worker using the command celery -A backend worker -l info I get the notice:
[2017-11-13 18:07:50,937: ERROR/MainProcess] consumer: Cannot connect to redis://localhost:6379/0: Error 99 connecting to localhost:6379. Cannot assign requested address.. Trying again in 4.00 seconds...
Notes:
I am able to telnet in to the redis container on port 6379. On the redis container, redis-server is running.
Is there anything else that I'm missing? I've gone pretty far down the rabbit hole, but feel like I'm missing something really simple.
DOCKER CONFIG FILES:
docker-compose.common.yml here
docker-compose.dev.yml here
回答1:
When you use docker-compose, you aren't going to be using localhost for inter-container communication, you would be using the compose-assigned hostname of the container. In this case, the hostname of your redis container is redis. The top level elements under services: are your default host names.
So for celery to connect to redis, you should try redis://redis:6379/0. Since the protocol and the service name are the same, I'll elaborate a little more: if you named your redis service "butter-pecan-redis" in your docker-compose, you would instead use redis://butter-pecan-redis:6379/0.
Also, docker-compose.dev.yml doesn't appear to have celery and redis on a common network, which might cause them not to be able to see each other. I believe they need to share at least one network in common to be able to resolve their respective host names.
Networking in docker-compose has an example in the first handful of paragraphs, with a docker-compose.yml to look at.
回答2:
You may need to add the link and depends_on sections to your docker compose file, and then reference the containers by their hostname.
Updated docker-compose.yml:
version: '2.1' services: db: image: postgres memcached: image: memcached redis: image: redis ports: - '6379:6379' backend-base: build: context: . dockerfile: backend/Dockerfile-base image: "/backend:base" backend: build: context: . dockerfile: backend/Dockerfile image: "/backend:${ENV:-local}" command: ./wait-for-it.sh db:5432 -- gunicorn backend.wsgi:application -b 0.0.0.0:8000 -k gevent -w 3 ports: - 8000 links: - db - redis - memcached depends_on: - db - redis - memcached celery: image: "/backend:${ENV:-local}" command: ./wait-for-it.sh db:5432 -- celery worker -E -B --loglevel=INFO --concurrency=1 environment: C_FORCE_ROOT: "yes" links: - db - redis - memcached depends_on: - db - redis - memcached frontend-base: build: context: . dockerfile: frontend/Dockerfile-base args: NPM_REGISTRY: http://.view.build PACKAGE_INSTALLER: yarn image: "/frontend:base" links: - db - redis - memcached depends_on: - db - redis - memcached frontend: build: context: . dockerfile: frontend/Dockerfile image: "/frontend:${ENV:-local}" command: 'bash -c ''gulp''' working_dir: /app/user environment: PORT: 3000 links: - db - redis - memcached depends_on: - db - redis - memcached
Then configure the urls to redis, postgres, memcached, etc. with:
redis://redis:6379/0postgres://user:pass@db:5432/database
