Dockerfile.postgres

# Demo: Postgres with DiffKeeper
FROM golang:1.23-alpine AS builder

WORKDIR /build

# Copy module definition first for better caching
COPY go.mod go.sum ./
RUN go mod download

# Copy full source so local packages resolve
COPY . .

RUN CGO_ENABLED=0 go build -ldflags="-w -s" -o diffkeeper .

# Final image with Postgres
FROM postgres:16-alpine

# Copy DiffKeeper agent
COPY --from=builder /build/diffkeeper /usr/local/bin/diffkeeper

# Create delta storage directory
RUN mkdir -p /deltas

# Set environment variables
ENV POSTGRES_USER=postgres
# Password must be supplied at runtime via -e POSTGRES_PASSWORD or secrets management
ENV POSTGRES_DB=testdb
ENV PGDATA=/var/lib/postgresql/data

# Wrapper script to start DiffKeeper + Postgres
RUN echo '#!/bin/sh' > /entrypoint-wrapper.sh && \
    echo 'exec /usr/local/bin/diffkeeper \' >> /entrypoint-wrapper.sh && \
    echo '  --state-dir=/var/lib/postgresql/data \' >> /entrypoint-wrapper.sh && \
    echo '  --store=/deltas/postgres.bolt \' >> /entrypoint-wrapper.sh && \
    echo '  -- docker-entrypoint.sh postgres "$@"' >> /entrypoint-wrapper.sh && \
    chmod +x /entrypoint-wrapper.sh

ENTRYPOINT ["/entrypoint-wrapper.sh"]
CMD []

# Volume for delta storage (small!)
VOLUME /deltas