Dockerizing a Rails + React App for the First Time

In 2022, I started moving beyond simple deployments on Heroku and exploring Docker for the first time. Docker seemed intimidating at first, but once I got a Rails + React app running in containers, it completely changed the way I thought about deployments and collaboration.

Here’s how I approached Dockerizing a full-stack application.

Why Docker Changed My Workflow

Consistency → If it runs on my machine, it runs everywhere.
Isolation → Rails, React, Postgres, Redis — each in its own container.
Collaboration → No more “it broke on my setup” excuses.
Deployment-ready → The same image could be shipped to AWS, GCP, or DigitalOcean.

Backend (Rails) Dockerfile

				
					# Dockerfile for Rails
FROM ruby:3.1

WORKDIR /app

RUN apt-get update -qq && apt-get install -y nodejs postgresql-client

COPY Gemfile* ./
RUN bundle install

COPY . .

CMD ["rails", "server", "-b", "0.0.0.0"]

Frontend (React) Dockerfile

				
					# Dockerfile for React
FROM node:16

WORKDIR /app

COPY package*.json ./
RUN npm install

COPY . .

# Build for production
RUN npm run build

CMD ["npm", "start"]

docker-compose.yml

To run backend, frontend, Postgres, and Redis together:

				
					version: "3.9"

services:
  backend:
    build: ./backend
    command: bundle exec rails s -b 0.0.0.0 -p 3000
    ports:
      - "3000:3000"
    volumes:
      - ./backend:/app
    depends_on:
      - db
      - redis

  frontend:
    build: ./frontend
    command: npm start
    ports:
      - "3001:3000"
    volumes:
      - ./frontend:/app

  db:
    image: postgres:14
    environment:
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: password
    ports:
      - "5432:5432"

  redis:
    image: redis:6
    ports:
      - "6379:6379"

First Run

				
					docker-compose build
docker-compose up

Rails API → http://localhost:3000
React frontend → http://localhost:3001
Postgres & Redis up and connected 🚀

Lessons Learned

Volumes are critical for hot reloading in development.
.env files are the right way to manage secrets and configs.
Keep separate configs for dev and production (dev = hot reload, prod = prebuilt images).
Docker isn’t just for deployment — it’s for team consistency.

Final Thoughts

Docker felt like a steep learning curve at first, but it turned out to be one of the most valuable tools I picked up in 2022. It simplified my deployments, gave my team a common environment, and made me feel like I was building “real” production-ready systems.