Docker Compose Overriding

Question

I have two Docker Compose files, docker-compose.yml looks like this

version: '2'
services:
  mongo:
    image: mongo:3.2
    restart: always
    volumes:
      - /mnt/data/mongodb/data/db:/data/db
  redis:
    image: redis:3
    restart: always
  application:
    build: .
    image: localregistry:5000/mz_application:latest
    ports:
      - "3000:3000"
    links:
      - mongo:mongo
      - redis:redis
    restart: always

and another file used when I do deployment docker-deploy.yml

version: '2'
services:
  application:
    image: localregistry5000/mz_application:latest
    links:
      - mongo:mongo
      - redis:redis
    restart: always

  nginx:
    restart: always
    build: ./nginx/
    ports:
      - "80:80"
    volumes_from:
      - application
    restart: always
    links:
      - application:application
    command: /bin/bash -c "nginx -g 'daemon off;'"
    tty: false

So the idea behind using those files is as follows. When I run

docker-compose build

it builds and pushes an image to our local docker registry.

docker-compose -f docker-compose.yml -f docker-deploy.yml build &&
docker-compose -f docker-compose.yml -f docker-deploy.yml up -d

To deploy and run application pulled from the local registry rather than being rebuilt.

Unfortunately it rebuilds it because when I override application, build is still present as it is taken from docker-compose.yml file. How to I remove it ? Is there a way to do this - building and pushing and image using one docker-compose file and then only pull using docker compose file override ?

Answer 1

First of all, if you let me, I found several things to consider. I don't know why do you want to have the same two build destination images but anyway I'll try to answer solutions better than ask why do you try to do that.

1. Changing image name you build different images. Maybe you could try with "deploy-version" for example.
2. If you don't want to change image name because you prefer (I don't know why) build it twice, you could try following command, setting different container_name in compose files:

Furthermore, note that in your docker-deploy.yml file, for application service, you're not defining build section, so, docker-compose -f docker-deploy.yml build will build image with default Dockerfile and path: .

services:
  application:
    build: .
    image: localregistry:5000/mz_application:latest
    ports:
      - "3000:3000"
    links:
      - mongo:mongo
      - redis:redis
    restart: always
    container_name: app_compose

---

services:
  application:
    image: localregistry:5000/mz_application:latest
    links:
      - mongo:mongo
      - redis:redis
    restart: always
    container_name: app_deploy

3. Consider that multiple docker-compose build should be defined with different images. Maybe you are trying to deploy different containers from the same image. I see that only difference between application service definition in both docker-compose files is ports declaration, because build: . is the same that don't put anything. When you use docker-compose build command, it ignores ports: section. When you use docker-compose up command, it ignores build: section.

Definitively, if you want to get up a concrete service without rebuilding avoiding image rewriting, you can also do:

docker-compose -f docker-compose.yml build
docker-compose -f docker-deploy.yml run -d nginx /bin/bash -c "nginx -g 'daemon off;'"