# Build stage
FROM golang:1.23.12-alpine AS builder

WORKDIR /build

COPY go.mod ./
COPY main.go .

# CGO_ENABLED=0 for static binary
# -ldflags for smaller binary size
# GOOS=linux for OS compatibility
RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -ldflags '-w -s' -o interview-server ./main.go

# Run stage
FROM debian:bullseye-slim

# Install ca-certificates for HTTPS
RUN apt-get update && \
    apt-get install -y --no-install-recommends ca-certificates && \
    rm -rf /var/lib/apt/lists/*

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

# Change directory for runtime
WORKDIR /app

# Copy the binary from builder
COPY --from=builder /build/interview-server .

# Copy entrypoint script
COPY docker-entrypoint.sh .
RUN chmod +x docker-entrypoint.sh

# Ensure non-root user is running the applicatoin
USER appuser

# Expose on default port
EXPOSE 8080

# Path to config file can be set via ENV variable
ENV CONFIG_FILE=""

# Run the application using JSON form for proper signal handling
ENTRYPOINT ["./docker-entrypoint.sh"]