redis server error docker app: temporary failure in name resolution

I am trying to run a redis server for task queues. It works on my local laptop but when I port it to a virtual machine (CentOS) it gives me this error:

redis.exceptions.ConnectionError: Error -3 connecting to redis:6379. Temporary failure in name resolution.

I looked it up and there are no threads with this specific error. Doesn't seem like anyone has encountered it? My code snippet is like:

    redis_url = current_app.config['REDIS_URL']

    with Connection(redis.from_url(redis_url)):
        q = Queue()
        task = q.enqueue(upload_data_to_ES, args=(data,), job_timeout=150, result_ttl=1000)

The only major difference is that I set the docker-compose.yml file to have network_mode: "host" so that it can communicate with an elastic search server on the virtual machine. Would this cause the issue? I don't know how they are related. Help would be greatly appreciated.

My docker-compose.yml file looks like this:

version: '3.7'

services:
  gilsonapp:
    build: .
    network_mode: "host"
    image: gilsonapp:latest
    container_name: gilsonapp
    ports:
      - 8003:8003
    command: python app.py
    volumes:
      - ./app:/usr/src/app
      - /test_files:/usr/src/app/mnt/tsl_files
    environment:
      - FLASK_DEBUG=1
      - FLASK_ENV=testing
      - REDIS_URL="redis://redis:6379/0"
    env_file:
      - oracle_env_vars
    working_dir: /usr/src/app
    depends_on:
      - redis

  worker:
    image: gilsonapp
    container_name: gilsonapp_worker
    command: python worker.py
    volumes:
      - ./app:/usr/src/app
    working_dir: /usr/src/app
    environment:
      - REDIS_URL="redis://redis:6379/0"
      - APP_SETTINGS=config.TestingConfig
    depends_on:
      - redis

  redis:
    image: redis:alpine
    expose:
      - '6379'