Use docker-compose and multiple Dockerfile in separate directories

Don't rename your Dockerfile to Dockerfile.db or Dockerfile.web, it may not be supported by your IDE and you will lose syntax highlighting.

As Kingsley Uchnor said, you can have multiple Dockerfile, one per directory, which represent something you want to build.

I like to have a docker folder which holds each applications and their configuration. Here's an example project folder hierarchy for a web application that has a database.

docker-compose.yml
docker
├── web
│   └── Dockerfile
└── db
    └── Dockerfile

docker-compose.yml example:

version: '3'
services:
  web:
    # will build ./docker/web/Dockerfile
    build: ./docker/web
    ports:
     - "5000:5000"
    volumes:
     - .:/code
  db:
    # will build ./docker/db/Dockerfile
    build: ./docker/db
    ports:
      - "3306:3306"
  redis:
    # will use docker hub's redis prebuilt image from here:
    # https://hub.docker.com/_/redis/
    image: "redis:alpine"

docker-compose command line usage example:

# The following command will create and start all containers in the background
# using docker-compose.yml from current directory
docker-compose up -d

# get help
docker-compose --help

In case you need files from parent folder(s) as part of the build context of your Dockerfile

You can still use the above solution and place your Dockerfile in a directory such as docker/web/Dockerfile, all you need is to set the build context in your docker-compose.yml like this:

version: '3'
services:
  web:
    build:
      context: .
      dockerfile: ./docker/web/Dockerfile
    ports:
     - "5000:5000"
    volumes:
     - .:/code

The files hierarchy would loke like this:

config-on-root.ini
docker-compose.yml
docker
└── web
    ├── Dockerfile
    └── some-other-config.ini

The ./docker/web/Dockerfile will have access to desired files from the context like this:

FROM alpine:latest

COPY config-on-root.ini /
COPY docker/web/some-other-config.ini /

Also note that the build context will contain all the files of the specified directory. Make sure tou use a .dockerignore file to prevent loading undesired large files or directories to save time during build.

Here are some quick commands from tldr docker-compose. Make sure you refer to official documentation for more details.