Try changing 127.0.0.1:6379 to redis:6379.

it works for me. Just some details

docker-compose.yml

...
  redis:
    image: redis:latest
    ports:
      - "6379:6379"
    volumes:
      - 'redisdata:/data'
....    

CHANNEL_LAYERS = {
    'default': {
        'BACKEND': 'channels_redis.core.RedisChannelLayer',
        'CONFIG': {
            "hosts": [('redis', 6379)],
        },
    },
}

docker run -p 6379:6379 -d redis:5

and then start the server

i have the same issue,
the problem was the version of my python and also of the channels.
the tutorial woks perfectly with python=3.6, channels-redis 2.3.1 and daphne 2.0.2, channels =2.0.
You can follow the channels documentation of the channels version you have install.

So I got stuck on this and none of the answers seemed to work for me.

I found that docker would give the container its own IP address. to find the IP address in the command line I used;

‘docker ps’ to get the container ID.
‘docker inspect -f ‘{{range.NetworkSettings.Networks}}{{.IPAddress}}{{end}} * container-id*’ which gave me the IP.

This worked for;

CHANNEL_LAYERS = {
    'default': {
        'BACKEND': 'channels_redis.core.RedisChannelLayer',
        'CONFIG': {
            "hosts": [('172.20.0.1', 6379)],
        },
    },
}

I had a similar error with a Python FastAPI app running in a Docker container trying to connect to another container with http3.AsyncClient which also uses asyncio library.

One option which worked was to use IP of a container to which trying to connect. Get container id with docker ps then get container’s IP with one of the options:

docker inspect -f "{{range.NetworkSettings.Networks}}{{.IPAddress}}{{end}}" containerId

docker inspect -f "{{ .NetworkSettings.IPAddress }}" containerId

docker inspect containerId | grep IPAddress

The other was to run container on a host network which lets a container share your host’s networking stack

docker run --network=host --name myContainer -p 8080:8080 -d myImageName

then 127.0.0.1 can be used for a host to connect to.

Whether install Redis on your container manually and set it up with Django or set up docker-compose to do that for you.

docker run -p 6379:6379 -d redis:latest

or

My docker-compose.yml file

version: "3.9"
services:
  django:
    build:
      context: .
    image: django-chatapp-image
    container_name: django-chatapp
    volumes:
      - ./:/app
      - /virtual-env
    ports:
      - 8000:8000
    environment:
      - SOME_KEY=SOME_VAL
    depends_on:
      - redis

  redis:
    image: redis:alpine
    ports:
      - "6379:6379"
    volumes:
      - ./redisdata:/data

When you set up a service for redis the name of your service will be your host.

CHANNEL_LAYERS = {
    'default': {
        'BACKEND': 'channels_redis.core.RedisChannelLayer',
        'CONFIG': {
            "hosts": [('redis', 6379)],
        },
    },
}

know more

Okay, my search query was ConnectionRefusedError: [Errno 111] Connect call failed (‘127.0.0.1’, 5432) and google took me here. So, if anyone is looking for that issue, assuming,

1. You are trying to run your dockerised app
2. You know it is properly configured with postgress docker container
3. In your localhost

try,

docker run --network="host" container_id_or_name

Follow the Tutorial:

docker run -p 6379:6379 -d redis:5
before and then:
python3 manage.py runserver

If you restart your system you need to run docker run -p 6379:6379 -d redis:5 again before python3 manage.py runserver