Postgres Dockerfile with Custom Extensions using pgxn

Dockerfile

## Alternatives: postgres:15-alpine
ARG BASE_IMAGE=postgis/postgis:15-3.4-alpine

## Custom Alpine Postgres docker file with custom extensions
FROM ${BASE_IMAGE} as builder

# Install required dependencies
RUN apk --no-cache add \
    python3 \
    py3-pip \
    cmake \
    make \
    gcc \
    g++ \
    clang15 \
    llvm15 \
    postgresql-dev \
    && pip install pgxnclient

# Install extensions using pgxn
RUN pgxn install 'h3=4.1.3' \
    && pgxn install 'vector=0.4.4' \
    && pgxn install 'pg_uuidv7=1.3.0'

## Cleanup to reduce image size
RUN apk del \
    python3 \
    py3-pip \
    cmake \
    make \
    gcc \
    g++ \
    clang15 \
    llvm15 \
    postgresql-dev \
    && rm -rf /var/cache/apk/* \
    && rm -rf /root/.cache \
    && rm -rf /root/.pgxn

## Custom Alpine Postgres docker file with our extensions
FROM ${BASE_IMAGE}

## Copy all extensions from the builder stage
COPY --from=builder /usr/local/lib/postgresql/* /usr/local/lib/postgresql/
COPY --from=builder /usr/local/share/postgresql/extension/* /usr/local/share/postgresql/extension/