Dockerfile Deploys

Use a Dockerfile when you need full control.

When to use it

• Auto-detection picks the wrong stack.
• You need custom system packages.
• You run multiple build steps.
• Your app has a non-standard start command.

Requirements

Your container should:

• listen on the expected web port
• bind to 0.0.0.0
• keep the main process in the foreground
• write logs to stdout/stderr

Example

FROM node:20-alpine
WORKDIR /app
COPY package*.json ./
RUN npm ci
COPY . .
RUN npm run build
CMD ["npm", "start"]