Connection Error accessing postgres docker container - postgresql

Question

I setup a prisma project recently and here is my docker-compose.yml file
version: '3'
services:
prisma:
image: prismagraphql/prisma:1.31
restart: always
ports:
- '4030:4466'
environment:
TZ: ${PRISMA_DB_TIME_ZONE}
PRISMA_CONFIG: |
port: 4466
# managementApiSecret: my-secret
databases:
default:
connector: postgres
host: postgres
port: 5432
user: prisma
password: ${PRISMA_DB_PASSWORD}
migrations: true
rawAccess: true
postgres:
image: postgres:10.3
restart: always
ports:
- "3306:3306"
environment:
POSTGRES_USER: prisma
POSTGRES_PASSWORD: ${PRISMA_DB_PASSWORD}
TZ: ${PRISMA_DB_TIME_ZONE}
volumes:
- postgres:/var/lib/postgresql/data
volumes:
prisma:
postgres:
I can open my prisma playground and it functions without any issue. but I can't create a direct connection to the postgre container with dbeaver.
dbeaver Error message
Connection reset
Why my connection to the database fails?
This photo will be helpful.

Answer 1

postgres by default listens on port 5432.
In your postgres container specification, you should expose the port 5432 not 3306.
version: '3'
services:
prisma:
image: prismagraphql/prisma:1.31
restart: always
ports:
- '4030:4466'
environment:
TZ: ${PRISMA_DB_TIME_ZONE}
PRISMA_CONFIG: |
port: 4466
# managementApiSecret: my-secret
databases:
default:
connector: postgres
host: postgres
port: 5432
user: prisma
password: ${PRISMA_DB_PASSWORD}
migrations: true
rawAccess: true
postgres:
image: postgres:10.3
restart: always
ports:
- "5432:5432"
environment:
POSTGRES_USER: prisma
POSTGRES_PASSWORD: ${PRISMA_DB_PASSWORD}
TZ: ${PRISMA_DB_TIME_ZONE}
volumes:
- postgres:/var/lib/postgresql/data
volumes:
prisma:
postgres:
If 5432 port in your host is already in use and if you want to use 3306 instead , then you can do port forwarding like below:
postgres:
image: postgres:10.3
restart: always
ports:
- "3306:5432"
environment:
POSTGRES_USER: prisma
POSTGRES_PASSWORD: ${PRISMA_DB_PASSWORD}
TZ: ${PRISMA_DB_TIME_ZONE}
volumes:
- postgres:/var/lib/postgresql/data
UPDATE - 1
Reason why prisma can access postgres
ports section is meant only to make our services accessible in host level. But in the container level, If a port is open in a container, any other running container can access that port with the help of networks or links section.
By default, docker-compose will create a network per docker-compose.yml file and joins all the services in that file into that network.
That's the reason we could use the <service name> as the hostname and compose will resolve that name to the ip-address of the respective (in your case postgres) container.