Knex Migration with Docker Compose Psql - postgresql

Question

I have a problem migrating using Knex js inside my docker-compose container.
the problem is that npm run db (knex migrate:rollback && knex migrate:latest && knex seed:run) would run right before the database is even created. Is there anyway to say that I would only like to run npm run db after the database has been created?
NOTE : if I do this npm commands on the docker terminal after it has been built everything works fine. just fyi
here is my docker-compose.yml
version: '3.6'
services:
#Backend api
server:
container_name: server
build: ./
command: npm run db
working_dir: /user/src/server
ports:
- "5000:5000"
volumes:
- ./:/user/src/server
environment:
POSTGRES_URI: postgres://test:test#192.168.99.100:5432/interapp
links:
- postgres
# PostgreSQL database
postgres:
environment:
POSTGRES_USER: test
POSTGRES_PASSWORD: test
POSTGRES_DB: interapp
POSTGRES_HOST: postgres
image: postgres
ports:
- "5432:5432"
and here is my Dockerfile
FROM node:10.14.0
WORKDIR /user/src/server
COPY ./ ./
RUN npm install
CMD ["/bin/bash"]

Answer 1

on the docker-compose.yml file, using sh (bash) for a contained environment context for your command to run in. ie. sh -c 'npm run db'
your docker-compose file would now be
secondly, use the depends_on step to wait for the database to start
services:
#Backend api
server:
container_name: server
build: ./
command: sh -c 'npm run db'
working_dir: /user/src/server
depends_on:
-postgres
ports:
- "5000:5000"
volumes:
- ./:/user/src/server
environment:
POSTGRES_URI: postgres://test:test#192.168.99.100:5432/interapp
links:
- postgres

Answer 2

Simply adding depends_on to server service should do the trick here.
services:
server:
depends_on:
- postgres
...
This will cause docker-compose to start postgres container before the server container. It will not however wait for postgres to be ready. In this case it shouldn't be problem, because postgres starts really quickly.
If you want something more solid, or depends_on doesn't do the trick, you can add entrypoint wrapping script to your container. See https://docs.docker.com/compose/startup-order/, where you can read more about it. There are also links to tools, so you don't have to write your own script from scratch.