add source code and readme

build/postgresql-postgis/Dockerfile

@@ -0,0 +1,35 @@
+# CloudNativePG-compatible PostGIS image
+# Uses imresamu/postgis as base which has ARM64 support
+FROM imresamu/postgis:16-3.4
+
+# Get additional tools from CloudNativePG image  
+FROM ghcr.io/cloudnative-pg/postgresql:16.6 as cnpg-tools
+
+# Final stage: PostGIS with CloudNativePG tools
+FROM imresamu/postgis:16-3.4
+
+USER root
+
+# Fix user ID compatibility with CloudNativePG (user ID 26)
+# CloudNativePG expects postgres user to have ID 26, but imresamu/postgis uses 999
+# The tape group (ID 26) already exists, so we'll change postgres user to use it
+RUN usermod -u 26 -g 26 postgres && \
+    delgroup postgres && \
+    chown -R postgres:tape /var/lib/postgresql && \
+    chown -R postgres:tape /var/run/postgresql
+
+# Copy barman and other tools from CloudNativePG image
+COPY --from=cnpg-tools /usr/local/bin/barman* /usr/local/bin/
+
+# Install any additional packages that CloudNativePG might need
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends \
+        curl \
+        jq \
+    && rm -rf /var/lib/apt/lists/*
+
+# Switch back to postgres user (now with correct ID 26)
+USER postgres
+
+# Keep the standard PostgreSQL entrypoint
+# CloudNativePG operator will manage the container lifecycle