connection refused when trying to connect redis using docker compose file

I have a problem trying to connect to redis using redis-golang driver.
this is my docker-compose.yml file :

version: "3"

services:
  driver:
    build: ./API-Golang
    command: go run app.go
    volumes:
     - ./API-Golang:/app
    ports:
      - "8080:8080"
    depends_on:
      - db
      - redis
    links :
      - redis
      - db
  redis:
    image: redis
    container_name: redis
    ports: ["6379:6379"]
  db:
    image: mongo:3.4.2
    container_name: mongodb
    ports : ["27017:27017"]

and this the code where I try to connect to redis (API-Golang/database/allSystem.go):

redisConn := RedisHost{
	Address:  "localhost:6379",
	Password: "",
	DB:       0,
}

redisConnection, err := redisConn.Connect()
if err != nil {
	panic(err)
}

I have tried to change localhost to redis for the host but still it doesn't work. Here is the error :

driver_1  | panic: dial tcp [::1]:6379: getsockopt: connection refused
driver_1  | 
driver_1  | goroutine 1 [running]:
driver_1  | github.com/Gujarats/API-Golang/database.SystemConnection(0x48)
driver_1  | 	/go/src/github.com/Gujarats/API-Golang/database/allSystem.go:32 +0x3d3
driver_1  | main.main()
driver_1  | 	/go/src/github.com/Gujarats/API-Golang/app.go:24 +0x34
driver_1  | exit status 2

Any idea what's wrong?

Source Code

There are several things to be aware of when using depends_on:

• depends_on will not wait for db and redis to be “ready” before starting web - only until they have been started. If you need to wait for a service to be ready, see Controlling startup order for more on this problem and strategies for solving it.
• Version 3 no longer supports the condition form of depends_on.
• The depends_on option is ignored when deploying a stack in swarm mode with a version 3 Compose file.

This is stupid I wrote the depends_on not in order I fix the issue writing the order like this :

depends_on:
  - redis
  - db

Before this I wrote it db first. and do not forget to change the host to appropriate name just like in the docker-compose.yml file. In this case is redis = redis and mongodb = db.

I forget that in app.go I call redis first then mongodb.