dockerfile for aws fargate

Dockerfile

# Multi-stage build for optimization
FROM ruby:3.2.2-slim AS builder

# Install essential build dependencies
RUN apt-get update && apt-get install -y \
    build-essential \
    libpq-dev \
    && rm -rf /var/lib/apt/lists/*

# Set working directory
WORKDIR /app

# Copy only dependency files first for caching
COPY Gemfile Gemfile.lock ./

# Install gems with caching
RUN bundle config set --local without 'development test' \
    && bundle install --jobs 4 --retry 3

# Copy the rest of the application
COPY . .

# Precompile assets
RUN SECRET_KEY_BASE=placeholder bundle exec rails assets:precompile

# Final stage
FROM ruby:3.2.2-slim

# Install runtime dependencies
RUN apt-get update && apt-get install -y \
    libpq-dev \
    && rm -rf /var/lib/apt/lists/*

# Set working directory
WORKDIR /app

# Copy from builder stage
COPY --from=builder /usr/local/bundle /usr/local/bundle
COPY --from=builder /app /app

# Set production environment
ENV RAILS_ENV=production
ENV RAILS_SERVE_STATIC_FILES=true
ENV RAILS_LOG_TO_STDOUT=true

# Expose port
EXPOSE 3000

# Health check
HEALTHCHECK --interval=30s --timeout=30s --start-period=5s --retries=3 \
  CMD curl -f http://localhost:3000/health || exit 1

# Use non-root user for security
RUN addgroup --system rails && \
    adduser --system --ingroup rails rails
USER rails

# Startup command with performance tuning
CMD ["bundle", "exec", "rails", "server", "-b", "0.0.0.0", "-p", "3000", "-e", "production"]