FROM golang:1.25-alpine AS builder

WORKDIR /src
COPY go.mod go.sum ./
RUN go mod download
COPY main.go .

# Compile a highly optimized, completely static binary
RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o backup-app main.go

# --- Stage 2: Final Light Execution Layer ---
FROM postgres:18-alpine

WORKDIR /app

# Copy the compiled executable from the builder layer
COPY --from=builder /src/backup-app .

# Set up environmental time out-of-the-box
ENV TZ=Europe/Rome
ENV PGTZ=Europe/Rome

ENTRYPOINT ["/app/backup-app"]
CMD ["cron-init"]