Fly · Dotenvx

Find code examples for this guide on GitHub.

Initial setup

Create a Hello World app, a Dockerfile, and fly.toml, then deploy.

# Dockerfile
FROM node:20
WORKDIR /app
COPY package*.json ./
RUN npm install
COPY . .
EXPOSE 3000
CMD ["node", "index.js"]

# .dockerignore
.env.keys

[http_service]
  internal_port = 3000

flyctl launch
flyctl deploy

Run dotenvx

Install dotenvx in your Dockerfile and prepend your app command with dotenvx run --.

# Dockerfile
FROM node:20
WORKDIR /app

# Install dotenvx
RUN curl -sfS https://dotenvx.sh/install.sh | sh

COPY package*.json ./
RUN npm install
COPY . .
EXPOSE 3000

# Prepend dotenvx run
CMD ["dotenvx", "run", "--", "node", "index.js"]

If you prefer, install from GitHub Releases or view the install.sh file before executing.

Encrypt production

# .env.production
HELLO="production"

$ dotenvx encrypt -f .env.production

Commit .env.production. Do not commit .env.keys.

Set decryption key

flyctl secrets set DOTENV_PRIVATE_KEY_PRODUCTION='your-private-key'
flyctl deploy

Your app restarts and env is injected from the encrypted .env.production file.