Use ENV again

Dockerfile

@@ -1,16 +1,17 @@
 ARG POSTGRES_VERSION=17
+FROM postgres:${POSTGRES_VERSION}
 
-FROM postgres:$POSTGRES_VERSION
+ENV POSTGRES_VERSION=${POSTGRES_VERSION}
 
-RUN apt-get update
-RUN apt-mark hold locales
-RUN apt-get install curl ca-certificates -y
-RUN install -d /usr/share/postgresql-common/pgdg
-RUN curl -o /usr/share/postgresql-common/pgdg/apt.postgresql.org.asc --fail https://www.postgresql.org/media/keys/ACCC4CF8.asc
-RUN sh -c 'echo "deb [signed-by=/usr/share/postgresql-common/pgdg/apt.postgresql.org.asc] https://apt.postgresql.org/pub/repos/apt bookworm-pgdg main" > /etc/apt/sources.list.d/pgdg.list'
+# Install prerequisites and configure PostgreSQL for wal2json
+RUN apt-get update && apt-mark hold locales && \
+    apt-get install -y curl ca-certificates && \
+    install -d /usr/share/postgresql-common/pgdg && \
+    curl -o /usr/share/postgresql-common/pgdg/apt.postgresql.org.asc --fail https://www.postgresql.org/media/keys/ACCC4CF8.asc && \
+    sh -c 'echo "deb [signed-by=/usr/share/postgresql-common/pgdg/apt.postgresql.org.asc] https://apt.postgresql.org/pub/repos/apt bookworm-pgdg main" > /etc/apt/sources.list.d/pgdg.list'
 
-RUN echo "Setting up PostgreSQL $POSTGRES_VERSION with wal2json"
-RUN apt-get update
-RUN apt-get install postgresql-server-dev-$POSTGRES_VERSION -y
-RUN sh -c 'export PATH=/usr/lib/postgresql/$POSTGRES_VERSION/bin:$PATH'
-RUN apt-get install postgresql-$POSTGRES_VERSION-wal2json -y
+RUN echo "Setting up PostgreSQL ${POSTGRES_VERSION} with wal2json" && \
+    apt-get update && \
+    apt-get install -y postgresql-server-dev-${POSTGRES_VERSION} && \
+    export PATH=/usr/lib/postgresql/${POSTGRES_VERSION}/bin:$PATH && \
+    apt-get install -y postgresql-${POSTGRES_VERSION}-wal2json