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Docker Sync

You may notice that running via Docker is slow. The preferred way to address this is to use use docker-sync to speed things up. Another is to run locally but that involves keeping up to date with dependencies as they change.

gem install docker-sync
  • Create a file docker-sync.yml at the root of your application:
docker-sync.yml
version: '2'
syncs:
  simple-sync:
    src: './'
    compose-file-path: docker-compose.dev.yml
  • Update your docker-compose.dev.yml as follows:
docker-compose.dev.yml
version: '3.8'

services:
  app:
    build: 
      context: .
      dockerfile: develop.Dockerfile
    container_name: example_app
    ports: 
      - 4000:4000
      - 9229:9229
    volumes: 
      - simple-sync:/app/:nocopy #  nocopy is important
    environment:
      - DB_CONNECTION_STRING=postgres://ola:@host.docker.internal/tsent_test

volumes:
  simple-sync:
    external: true

Major changes above:

  1. simple-sync volume added in the volumes section at the bottom of the file
  2. volume of the app updated to use the simple-sync volume defined at the bottom of the file

  • Run docker-sync start once prior to any docker commands such as npm run codegen.

  • Run docker-sync stop once done.

There's more advanced options here but that's out of the scope of this guide.