Added Docker setup for initial database import

This MR adds the import of an osm.pbf file into an empty database.

Related to https://git.gfz-potsdam.de/dynamicexposure/server-components/compositions/docker-openbuildingmap-import/-/merge_requests/2

\rfc @marius \approve @ds

files/start.sh

+#!/bin/bash
+
+# Copyright (C) 2021:
+#   Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentrum GFZ
+#
+# This program is free software: you can redistribute it and/or modify it
+# under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or (at
+# your option) any later version.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero
+# General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program. If not, see http://www.gnu.org/licenses/.
+
+set -e
+printf "\nWelcome to the OpenBuildingMap importer\n\n"
+
+# Wait until database is up and available
+printf "Connecting to PostgreSQL on \"${OBM_DATABASE_HOST}\":\n"
+until psql -h "${OBM_DATABASE_HOST}" -t -U "${OBM_DATABASE_USER}" -c 'SELECT datname FROM pg_database;'; do
+  printf "Database is unavailable - trying again in 10s\n"
+  sleep 10
+done
+
+# Report if database was created or reused
+if ! psql -h "${OBM_DATABASE_HOST}" -U "${OBM_DATABASE_USER}" -c "\c ${OBM_DATABASE_NAME}"; then
+  psql -h "${OBM_DATABASE_HOST}" -U "${OBM_DATABASE_USER}" -c "CREATE DATABASE ${OBM_DATABASE_NAME}"
+
+  if psql -h "${OBM_DATABASE_HOST}" -U "${OBM_DATABASE_USER}" -c "\c ${OBM_DATABASE_NAME}"; then
+    psql -h "${OBM_DATABASE_HOST}" -U "${OBM_DATABASE_USER}" ${OBM_DATABASE_NAME} -c 'CREATE EXTENSION postgis;'
+    printf " postgis extension added to ${OBM_DATABASE_NAME} database.\n"
+    psql -h "${OBM_DATABASE_HOST}" -U "${OBM_DATABASE_USER}" ${OBM_DATABASE_NAME} -c 'CREATE EXTENSION hstore;'
+    printf " hstore extension added to ${OBM_DATABASE_NAME} database.\n"
+    psql -h "${OBM_DATABASE_HOST}" -U "${OBM_DATABASE_USER}" ${OBM_DATABASE_NAME} -c 'CREATE EXTENSION btree_gin;'
+    printf " btree_gin extension added to ${OBM_DATABASE_NAME} database.\n"
+    psql -h "${OBM_DATABASE_HOST}" -U "${OBM_DATABASE_USER}" ${OBM_DATABASE_NAME} -c 'CREATE EXTENSION btree_gist;'
+    printf " btree_gist extension added to ${OBM_DATABASE_NAME} database.\n"
+
+  else 
+    printf "Error: Unable to create database for OpenBuildingMap!\n"
+    exit 1
+  fi
+fi
+
+# Prepare style file for osm2pgsql
+base_style="/usr/share/osm2pgsql/empty.style"
+if [ ! -r "${base_style}" ]
+then
+	printf "Cannot find the `empty.style` file of osm2pgsql\n"
+	exit 1
+fi
+cat /usr/share/osm2pgsql/empty.style > /usr/share/osm2pgsql/the.style
+cat ${OBM_IMPORT_STYLE} >> /usr/share/osm2pgsql/the.style
+
+# Import OSM data if database is empty
+database_exists=${psql -h ${OBM_DATABASE_HOST} -U ${OBM_DATABASE_USER} ${OBM_DATABASE_NAME} -t -c "SELECT CASE WHEN EXISTS (SELECT FROM pg_tables WHERE  schemaname = 'public' AND tablename  = 'planet_osm_line' LIMIT 1) THEN 'true' ELSE 'false' end;"}
+if ! ${database_exists}; then
+
+    # Import OpenStreetMap data
+    if [ -f "${OBM_IMPORT_FILE}" ]; then
+        printf " \nImporting OpenStreetMap data with "
+        osm2pgsql \
+          --host ${OBM_DATABASE_HOST} --username ${OBM_DATABASE_USER} --database ${OBM_DATABASE_NAME} \
+          --verbose \
+          --create \
+          --slim \
+          --style "/usr/share/osm2pgsql/the.style" \
+          --multi-geometry \
+          --hstore \
+          --latlong \
+          --extra-attributes \
+          --hstore-add-index \
+          --cache-strategy dense \
+          ${OBM_IMPORT_FILE}
+        printf "Success: OpenStreetMap data has been imported.\n"
+
+    else
+        printf "Error: No import file '${OBM_IMPORT_FILE}' has been found.\nGood bye.\n"
+        exit 1
+    fi
+fi