Cannot connect to redis in docker and django-CodePudding

I have run a redis container using this command: docker run -d --name redis -p 6379:6379 redis.

and I have run my Django app using this command: docker run -it -p 8000:8000 voucher.

and my connection redis url is redis://redis:6379/1.

But i cannot seem to connect to redis here is my error: redis.exceptions.ConnectionError: Error -2 connecting to redis:6379. Name or service not known.

PS: I'm not using docker-compose

CodePudding user response：

Both Container have to be in the same Docker network to be able to communicate via the Container names.

docker run -d --name redis --network your-network -p 6379:6379 redis

docker run -it --network your-network -p 8000:8000 voucher

CodePudding user response：

I have fix that by changing my redis connection url to redis://172.17.0.2:6379/1. But why is that ? How can I use container names instead of IPs?

This is your host IP. You have a few ways to solve your problem.

1 - Use the hardcoded IP as you did.

2 - Use docker link to connect applications like:

docker run --name my-redis-application --link my-redis-container:redis -d centos

3 - You can create a redis.conf with the follow content:

bind 0.0.0.0

and use it in the startup like:

docker run -v $(pwd):/usr/local/etc/redis/ --name redis -p 6379:6379 -d redis redis-server /usr/local/etc/redis/redis.conf

4 - You can use docker-compose to link then better, like in #2.

CodePudding user response：

Did you defined redis info in .env file? That could lead to connection error too.

/.env

REDIS_HOST=127.0.0.1
REDIS_PASSWORD=yourpassword/blank
REDIS_PORT=6379

CodePudding user response：

I have fix that by changing my redis connection url to redis://172.17.0.2:6379/1.
But why is that ? How can I use container names instead of IPs?

CodePudding user response：

I think the better option is docker-compose. if you like to use docker-compose here is the answer.

docker-compose.yml

version: "3.8"
services :
  redis:
    image : redis
    container_name : redis
    restart : unless-stopped
    ports: 
      - 6379:6379 
  voucher:
    build:
      image:voucher
   ports:
     - 8000:8000
    depends_on:
      - redis

now you can connect to Redis using the service name "redis".