Docker Postgres database not running or accessible - docker

Question

Below is my Dockerfile:
FROM node:14
WORKDIR /workspace
COPY . .
COPY /prisma ./prisma/
RUN npm install
EXPOSE 3333
EXPOSE 9229
CMD [ "npm", "run", "start" ]
And my docker-compose.yml
version: '3.8'
services:
todoapp-api:
container_name: todoapp-api
build:
context: .
dockerfile: Dockerfile
ports:
- 3333:3333
postgres:
image: postgres:13.5
container_name: postgres
restart: always
environment:
- POSTGRES_USER=myuser
- POSTGRES_PASSWORD=mypassword
volumes:
- postgres:/var/lib/postgresql/data
ports:
- '5432:5432'
volumes:
postgres:
networks:
nestjs-crud:
And my .env:
DATABASE_URL="postgresql://myuser:mypassword#192.168.1.1/mydb?schema=public"
After struggling with making the database run and be accessible, I found out that one possible solution was to change the DATABASE_URL. As you can see, I am writing my IP Address there to get it to run and this works for me. However, when I replace 192.168.1.1 with the name of the service: postgres, it stops working and I get the error:
Can't reach database server at postgres:5432
Writing the IP address is not ideal of course. However, if I don't write the IP address then the database server just doesn't work.

Answer 1

I think you may need to atributte networks in the containers specs. You already defined what networks you have in the YAML but they need to be inserted in container's spec like
todoapp-api:
container_name: todoapp-api
networks:
- nestjs-crud
build:
context: .
dockerfile: Dockerfile
ports:
- 3333:3333
networks:
nestjs-crud:
internal: true
My recomendation is to create one network for the db and other for the API, then assing the network db for the db, and both in the API, thus, the API can acess db network. Than, you can acess the db by the host nestjs-crud.postgres

Answer 2

To bounce back, on the point of the comment above, the two services are not in the same network, which is why you have the concern. To solve this problem, it will be necessary to put the services in the same network by putting the mention:
networks:
- nestjs-crud
and depends_on in todoapp-api
in the todoapp-api and postgres service, this becomes:
version: '3.8'
services:
todoapp-api:
container_name: todoapp-api
build:
context: .
dockerfile: Dockerfile
ports:
- 3333:3333
networks:
- nestjs-crud
depends_on:
- postgres
postgres:
image: postgres:13.5
container_name: postgres
restart: always
environment:
- POSTGRES_USER=myuser
- POSTGRES_PASSWORD=mypassword
volumes:
- postgres:/var/lib/postgresql/data
ports:
- '5432:5432'
networks:
- nestjs-crud
volumes:
postgres:
networks:
nestjs-crud:
And add in .env database service name.