update with latest build versions, includes custom build for postgres and migrating from v16 to v18

build/postgresql-postgis/initdb-postgis.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+
+set -e
+
+# Perform all actions as $POSTGRES_USER
+export PGUSER="$POSTGRES_USER"
+
+# Create the 'template_postgis' template db
+psql --dbname="$POSTGRES_DB" <<- 'EOSQL'
+CREATE DATABASE template_postgis IS_TEMPLATE true;
+EOSQL
+
+# Load PostGIS into both template_database and $POSTGRES_DB
+for DB in template_postgis "$POSTGRES_DB"; do
+	echo "Loading PostGIS extensions into $DB"
+	psql --dbname="$DB" <<-'EOSQL'
+		CREATE EXTENSION IF NOT EXISTS postgis;
+		CREATE EXTENSION IF NOT EXISTS postgis_topology;
+		CREATE EXTENSION IF NOT EXISTS fuzzystrmatch;
+		CREATE EXTENSION IF NOT EXISTS postgis_tiger_geocoder;
+EOSQL
+done