Added Docker setup for initial database import

Dockerfile

+# 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/.
+
+FROM debian:bullseye-slim
+
+ENV DEBIAN_FRONTEND noninteractive
+
+# Install software
+RUN apt-get update
+RUN apt-get install --no-install-recommends -y osm2pgsql postgresql-client
+
+# Cleanup
+RUN apt-get autoremove --yes $build_dependencies && \ 
+    apt-get autoremove --yes && \
+    apt-get clean --yes && \
+    rm -rf /var/lib/apt/* /var/cache/apt/* /root/.cache
+
+VOLUME ["/tmp/import"]
+
+# Start script
+COPY ./files/start.sh /usr/local/bin
+CMD /usr/local/bin/start.sh

LICENSE

@@ -616,4 +616,4 @@ an absolute waiver of all civil liability in connection with the
 Program, unless a warranty or assumption of liability accompanies a
 copy of the Program in return for a fee.
 
- END OF TERMS AND CONDITIONS
\ No newline at end of file
+ END OF TERMS AND CONDITIONS

README.rst

-===================
-Docker OBM Importer
-===================
+=====================
+Docker OBM import OSM
+=====================
 
-This is a Docker container for importing and updating data for the 
-OpenBuildingMap database.
+Import data from OpenStreetMap (OSM) to the OpenBuildingMap (OBM) Buildings database using
+`osm2pgsql <https://github.com/openstreetmap/osm2pgsql>`__ and keep it up-to-data through
+pulling regular updates from OSM.
+
+Define variables
+----------------
+
+* :code:`OBM_DATABASE_HOST` - Host url or IP of the database
+* :code:`OBM_DATABASE_NAME` - Name of the database
+* :code:`OBM_DATABASE_USER` - User to connect to the database
+* :code:`OBM_IMPORT_STYLE` - Absolute path to an available osm2pgsql style file
+* :code:`OBM_IMPORT_FILE` - Absolute path to an available OSM pbf-file containing data of an area
 
 Copyright and copyleft
 ----------------------
 
-Copyright (C) 2020
+Copyright (c) 2021
 
 * Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentrum GFZ
 

files/start.sh

+#!/bin/bash
+#
+# Initialize import of OpenStreetMap data into OpenBuildingMap
+
+# 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/.
+
+#######################################
+# Main function of this script, to be executed for initial import.
+# Globals:
+#   OBM_DATABASE_HOST
+#   OBM_DATABASE_NAME
+# Arguments:
+#   None
+#######################################
+function main() {
+  printf "Connecting to PostgreSQL on '%s':\n" "${OBM_DATABASE_HOST}"
+
+  # Wait until database comes up and is available
+  until execute_database_command "SELECT datname FROM pg_database;"; do
+    printf "Database is unavailable - trying again in 10s\n"
+    sleep 10
+  done
+
+  # Initiate new or reuse existing database
+  if execute_database_command "\connect ${OBM_DATABASE_NAME}"; then
+    printf "Reuse existing database: %s\n" "${OBM_DATABASE_NAME}"
+  else
+    execute_database_command "CREATE DATABASE ${OBM_DATABASE_NAME};"
+    add_database_extensions
+    printf "Initiated new database: %s\n" "${OBM_DATABASE_NAME}"
+  fi
+
+  # Obtain mapping information for database schema
+  assemble_opentstreetmap_database_style
+
+  # Import OpenStreetMap data if database is empty
+  database_exists=$(psql --host="${OBM_DATABASE_HOST}" \
+    --username="${OBM_DATABASE_USER}" "${OBM_DATABASE_NAME}" --tuples-only \
+    --command="SELECT CASE WHEN EXISTS \
+	  (SELECT FROM pg_tables WHERE schemaname = 'public' \
+	  AND tablename = 'planet_osm_line' LIMIT 1) THEN 'true' ELSE 'false' end;")
+  if ${database_exists}; then
+    printf "Assuming already imported database: %s\n" "${OBM_DATABASE_NAME}"
+  else
+    import_openstreetmap_data
+    printf "OpenStreetMap data has been imported.\n"
+  fi
+}
+
+#######################################
+# Exectute postgresql command outside of a specific database.
+# Globals:
+#   OBM_DATABASE_HOST
+#   OBM_DATABASE_USER
+# Arguments:
+#   Query command
+#######################################
+function execute_database_command() {
+  psql --host="${OBM_DATABASE_HOST}" --username="${OBM_DATABASE_USER}" --command="${1}"
+}
+
+#######################################
+# Exectute postgresql query on a certain database.
+# Globals:
+#   OBM_DATABASE_HOST
+#   OBM_DATABASE_NAME
+#   OBM_DATABASE_USER
+# Arguments:
+#   Query command
+#######################################
+function execute_database_query() {
+  psql --host="${OBM_DATABASE_HOST}" --username="${OBM_DATABASE_USER}" "${OBM_DATABASE_NAME}" \
+    --command="${1}"
+}
+
+#######################################
+# Add geospatial and advanced index extensions to a postgresql database.
+# Globals:
+#   OBM_DATABASE_HOST
+#   OBM_DATABASE_NAME
+#   OBM_DATABASE_USER
+# Arguments:
+#   None
+#######################################
+function add_database_extensions() {
+  if psql --host"=${OBM_DATABASE_HOST}" --username="${OBM_DATABASE_USER}" \
+    --command="\connect ${OBM_DATABASE_NAME}"; then
+
+    if execute_database_query "CREATE EXTENSION postgis;"; then
+      printf " postgis extension added to %s database.\n" "${OBM_DATABASE_NAME}"
+    else
+      printf " Could not add postgis extension added to %s database.\nAborting.\n" "${OBM_DATABASE_NAME}"
+      exit 1
+    fi
+
+    if execute_database_query "CREATE EXTENSION hstore;"; then
+      printf " hstore extension added to %s database.\n" "${OBM_DATABASE_NAME}"
+    else
+      printf " Could not add hstore extension added to %s database.\nAborting.\n" "${OBM_DATABASE_NAME}"
+      exit 1
+    fi
+
+    if execute_database_query "CREATE EXTENSION btree_gin;"; then
+      printf " btree_gin extension added to %s database.\n" "${OBM_DATABASE_NAME}"
+    else
+      printf " Could not add btree_gin extension added to %s database.\nAborting.\n" "${OBM_DATABASE_NAME}"
+      exit 1
+    fi
+
+    if execute_database_query "CREATE EXTENSION btree_gist;"; then
+      printf " btree_gist extension added to %s database.\n" "${OBM_DATABASE_NAME}"
+    else
+      printf " Could not add btree_gist extension added to %s database.\nAborting.\n" "${OBM_DATABASE_NAME}"
+      exit 1
+    fi
+
+  else
+    printf "Error: Unable to connect to database: %s\n" "${OBM_DATABASE_NAME}"
+    exit 1
+  fi
+}
+
+#######################################
+# # Prepare style file for osm2pgsql, based on standard 'empty.style' and provided style file.
+# Globals:
+#   OBM_IMPORT_STYLE
+# Arguments:
+#   None
+# Outputs:
+#   Writes combined style file to '/usr/share/osm2pgsql/the.style'
+#######################################
+function assemble_opentstreetmap_database_style() {
+  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 OpenStreetMap Data file into database with osm2pgsql.
+# Globals:
+#   OBM_IMPORT_FILE
+#   OBM_DATABASE_HOST
+#   OBM_DATABASE_USER
+#   OBM_DATABASE_NAME
+# Arguments:
+#   None
+#######################################
+function 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 \
+      "${OBM_IMPORT_FILE}"
+  else
+    printf "Error: Import file '%s' not found.\nAborting.\n" "${OBM_IMPORT_FILE}"
+    exit 1
+  fi
+}
+
+# Start the script
+printf "\nWelcome to the OpenBuildingMap importer\n\n"
+
+# Call main function of the script
+main