How do I use environment variables in a Dockerized React app?

How do I use environment variables in a Dockerized React app?

You can use environment variables in a Dockerized React app by defining them in your Dockerfile or docker-compose.yml file.

Can you give me an example of how to set them up in the Dockerfile?

Sure! In your Dockerfile, you can use the ARG instruction to define variables and then use ENV to set them. For example:

ARG REACT_APP_API_URL
ENV REACT_APP_API_URL=$REACT_APP_API_URL

What about using a .env file?

You can use a .env file with Docker Compose. Just create a .env file in your project root and reference it in your docker-compose.yml like this:

version: '3'
services:
  app:
    build:
      context: .
    env_file:
      - .env

How do I access these variables in my React code?

In your React code, you can access the environment variables using process.env.REACT_APP_API_URL. Just make sure to prefix your variable names with REACT_APP_.