Connection to postgres running in docker fails using go gorm - postgresql

Question

I am trying to connect to postgres running in a docker container from another container using gorm but I am getting
panic: failed to connect to host=postgres user=postgres database=test: dial error (dial tcp 192.168.176.5:6543: connect: connection refused)
My docker-compose:
version: '3'
services:
patients-service:
build:
context: ./../patients-service
dockerfile: ./../patients-service/patients-service.dockerfile
restart: always
deploy:
mode: replicated
replicas: 1
postgres:
image: 'postgres:14.2'
ports:
- "6543:5432"
restart: always
deploy:
mode: replicated
replicas: 1
environment:
POSTGRES_USER: postgres
POSTGRES_PASSWORD: password
POSTGRES_DB: test
volumes:
- ./db-data/postgres/:/var/lib/postgresql/data/
Here is my go file:
package database
import (
"gorm.io/driver/postgres"
"gorm.io/gorm"
"log"
)
var DB *gorm.DB
var err error
func Open() error {
dsn := "host=postgres port=6543 user=postgres password=password dbname=test sslmode=disable timezone=UTC connect_timeout=5"
DB, err = gorm.Open(postgres.Open(dsn), &gorm.Config{})
if err != nil {
return err
}
return nil
}
The weird thing is if I use port 5432 instead of 6543 in my code and change port mapping in docker-compose to - "5432:5432" it will connect just fine but I have postgres running locally and I don't want the two to interfere with each other since I am planning to connect to the one running in docker in DBeaver and localhost:5432 obviously connects to the local one.