Dockerfile

# Build stage
FROM rust:1.75-slim-bookworm AS builder

WORKDIR /app

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

# Copy manifests first for dependency caching
COPY Cargo.toml Cargo.lock ./

# Create a dummy main.rs to build dependencies
RUN mkdir src && echo "fn main() {}" > src/main.rs

# Build dependencies only (this layer will be cached)
RUN cargo build --release && rm -rf src

# Copy actual source code
COPY src ./src

# Touch main.rs to ensure it gets rebuilt
RUN touch src/main.rs

# Build the application
RUN cargo build --release

# Runtime stage
FROM debian:bookworm-slim

WORKDIR /app

# Install runtime dependencies (curl for health check)
RUN apt-get update && apt-get install -y \
    ca-certificates \
    curl \
    && rm -rf /var/lib/apt/lists/*

# Create a non-root user
RUN useradd -m -u 1000 appuser

# Copy the binary from builder
COPY --from=builder /app/target/release/url-shortener /app/url-shortener

# Create data directory for SQLite database
RUN mkdir -p /app/data && chown -R appuser:appuser /app

# Switch to non-root user
USER appuser

# Set environment variables
ENV DATABASE_URL=/app/data/urls.db
ENV HOST=0.0.0.0
ENV PORT=8080
ENV BASE_URL=http://localhost:8080
ENV RUST_LOG=info
ENV METRICS_ENABLED=true

# Expose the port
EXPOSE 8080

# Health check
HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
    CMD curl -f http://localhost:8080/health || exit 1

# Run the application
CMD ["./url-shortener"]