How to share directory from one container to another one using Docker Compose?

Question

dockerized Node.js application that I've developed holds the pb_migrations directory. In below Docker Compose document you can see that it depends on dockerized version of PocketBase.

What I want to achieve is that the PB container upon start should have the /app/pb_migrations directory from node container available on its /pb_migrations path.

I have tried to use named volume to do so, but the directory is empty for PB container. I don't want to copy the directory separately every time and mount it from the host, and would love to just use the docker-compose.yml document to run it.

version: '3.7'
services:
  pocketbase:
    image: spectado/pocketbase:0.19.2
    container_name: pocketbase
    restart: unless-stopped
    ports:
      - '8090:80'
    volumes:
      - pb_data:/pb_data
      - pb_migrations:/pb_migrations/
  app:
    image: app:latest
    container_name: app
    restart: unless-stopped
    env_file: .env
    volumes:
      - pb_migrations:/app/pb_migrations/
    ports:
      - '$PORT:$PORT'
    depends_on:
      - pocketbase
volumes:
  pb_data:
  pb_migrations:

Answer 1

to make the /app/pb_migrations dir from the app container available at the /pb_migrations path in the pocketbase container using Docker Compose, you can use a bind mount. Bind mounts let you directly connect a directory from one place, like the host or another container, into another container.

https://docs.docker.com/compose/compose-file/compose-file-v3/#volumes

you can checkout this answer