Knexfile not reading environment variables?

Question

I'm building a node/express service using docker and knex for database interaction. I have an env_file (defined in docker-compose file) that has some environment variables defined. The app is reading them correctly, as a console.log(process.env.DATABASE_USER); will log the correct value.

I followed the knex documentation to setup a knexfile that looks like so:

module.exports = {
  development: {
    client: 'pg',
    connection: {
      host: process.env.DATABASE_HOST,
      port: process.env.DATABASE_PORT,
      user: process.env.DATABASE_USER,
      password: process.env.DATABASE_PASSWORD,
      database: process.env.DATABASE_NAME_DEV,
    },
    migrations: {
      directory: __dirname + '/db/migrations',
    },
    seeds: {
      directory: __dirname + '/db/seeds',
    },
  },
};

If I hardcode the values into the knexfile, all is well. I can connect to the database, run migrations, etc.

When I use my environment variables (like above), they return undefined. Why is that?

UPDATE:

My docker compose file--api.env is just a basic .env file:

version: '3.3'

services:
  db:
    container_name: db
    build:
      context: ./services/api/src/db
      dockerfile: Dockerfile
    ports:
      - 5435:5432
    environment:
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=postgres

  nginx:
    container_name: nginx
    build: ./services/nginx
    restart: always
    ports:
      - 80:80
    depends_on:
      - api
    links:
      - api

  api:
    container_name: api
    build:
      context: ./services/api
      dockerfile: Dockerfile
    volumes:
      - './services/api:/usr/src/app'
      - './services/api/package.json:/usr/src/app/package.json'
    ports:
      - 8887:8888
    env_file: ./api.env
    depends_on:
      - db
    links:
      - db

  client:
    container_name: client
    build:
      context: ./services/client
      dockerfile: Dockerfile
    volumes:
      - './services/client:/usr/src/app'
    ports:
     - 3007:3000
    environment:
      - NODE_ENV=development
    depends_on:
      - api
    links:
      - api

Dockerfile for api service:

FROM node:latest

RUN mkdir /usr/src/app
WORKDIR /usr/src/app

ENV PATH /usr/src/app/node_modules/.bin:$PATH

ADD package.json /usr/src/app/package.json
RUN npm install

CMD ["npm", "start"]

Answer 1

You are not setting environment variables correctly in your setup. Maybe you are referring env_file wrong or you might have typo in your environment variable setups.

You need to give more information how is your docker compose file etc. Your knexfile.js looks correct.

EDIT:

From your docker-compose file it looks like you are passing database connection details only to your API container. Nothing shows how are you running knex migrations and how are you passing those variables for that call.

EDIT2:

bash -c "sleep 10 && npm run knex migrate:latest"

Command opens new shell, which does not have environment variables having connection details set. You need to pass environment variables with connection details to your shell.

Probably easiest for you would be to write run-migrations.sh script, which sets and passes variables correctly before running the migrate. Like:

for i in $(cat api.env); do
   export $i;
done;
sleep 10;
npm run knex migrate:latest;