Added first import logic

Makefile

-SOURCES=./spearhead
+SOURCES=./spearhead includes/*.sh
 LENGTH=96
 
 check: $(SOURCES)

includes/database.sh

+#!/bin/bash
+#
+# Helper functions around OpenStreetMap database import
+
+# 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/.
+
+#######################################
+# Wait until database comes up and is available
+# Globals:
+#   SPEARHEAD_DATABASE_HOST
+#   SPEARHEAD_DATABASE_USER
+# Arguments:
+#   Query command
+#######################################
+function database::wait_for_connection() {
+  until database::execute_command "SELECT datname FROM pg_database;"; do
+    printf "Database is unavailable - trying again in 10s\n"
+    sleep 10
+  done
+}
+
+#######################################
+# Execute a PostgreSQL command not addressing a particular database.
+# Globals:
+#   SPEARHEAD_DATABASE_HOST
+#   SPEARHEAD_DATABASE_USER
+# Arguments:
+#   Query command
+#######################################
+function database::execute_command() {
+  psql --host="${SPEARHEAD_DATABASE_HOST}" --username="${SPEARHEAD_DATABASE_USER}" --command="${1}"
+}
+
+#######################################
+# Execute PostgreSQL query on a certain database.
+# Globals:
+#   SPEARHEAD_DATABASE_HOST
+#   SPEARHEAD_DATABASE_NAME
+#   SPEARHEAD_DATABASE_USER
+# Arguments:
+#   Query command
+#######################################
+function database::execute_query() {
+  psql --host="${SPEARHEAD_DATABASE_HOST}" --username="${SPEARHEAD_DATABASE_USER}" \
+    "${SPEARHEAD_DATABASE_NAME}" --command="${1}"
+}
+
+#######################################
+# Add geospatial and advanced index extensions to a PostgreSQL database.
+# Globals:
+#   SPEARHEAD_DATABASE_HOST
+#   SPEARHEAD_DATABASE_NAME
+#   SPEARHEAD_DATABASE_USER
+# Arguments:
+#   None
+#######################################
+function database::add_extensions() {
+  if psql --host"=${SPEARHEAD_DATABASE_HOST}" --username="${SPEARHEAD_DATABASE_USER}" \
+    --command="\connect ${SPEARHEAD_DATABASE_NAME}"; then
+
+    if database::execute_query "CREATE EXTENSION postgis;"; then
+      printf " PostGIS extension added to %s database.\n" "${SPEARHEAD_DATABASE_NAME}"
+    else
+      printf " Could not add PostGIS extension added to %s database.\nAborting.\n" \
+        "${SPEARHEAD_DATABASE_NAME}"
+      exit 1
+    fi
+
+    if database::execute_query "CREATE EXTENSION hstore;"; then
+      printf " hstore extension added to %s database.\n" "${SPEARHEAD_DATABASE_NAME}"
+    else
+      printf " Could not add hstore extension added to %s database.\nAborting.\n" \
+        "${SPEARHEAD_DATABASE_NAME}"
+      exit 1
+    fi
+
+    if database::execute_query "CREATE EXTENSION btree_gin;"; then
+      printf " btree_gin extension added to %s database.\n" \
+        "${SPEARHEAD_DATABASE_NAME}"
+    else
+      printf " Could not add btree_gin extension added to %s database.\nAborting.\n" \
+        "${SPEARHEAD_DATABASE_NAME}"
+      exit 1
+    fi
+
+    if database::execute_query "CREATE EXTENSION btree_gist;"; then
+      printf " btree_gist extension added to %s database.\n" "${SPEARHEAD_DATABASE_NAME}"
+    else
+      printf " Could not add btree_gist extension added to %s database.\nAborting.\n" \
+        "${SPEARHEAD_DATABASE_NAME}"
+      exit 1
+    fi
+
+  else
+    printf "Error: Unable to connect to database: %s\n" "${SPEARHEAD_DATABASE_NAME}"
+    exit 1
+  fi
+}

includes/import.sh

+#!/bin/bash
+#
+# Helper functions around OpenStreetMap database import
+
+# 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/.
+
+#######################################
+# # Import OpenStreetMap Data file into database with osm2pgsql.
+# Globals:
+#   SPEARHEAD_IMPORT_FILE
+#   SPEARHEAD_IMPORT_STYLE
+#   SPEARHEAD_DATABASE_HOST
+#   SPEARHEAD_DATABASE_USER
+#   SPEARHEAD_DATABASE_NAME
+# Arguments:
+#   None
+#######################################
+function import::openstreetmap_data() {
+
+  if [[ -f "${SPEARHEAD_IMPORT_FILE}" ]]; then
+    printf " \nImporting OpenStreetMap data with "
+    osm2pgsql \
+      --host "${SPEARHEAD_DATABASE_HOST}" --username "${SPEARHEAD_DATABASE_USER}" \
+      --database "${SPEARHEAD_DATABASE_NAME}" \
+      --verbose \
+      --create \
+      --slim \
+      --style "${SPEARHEAD_IMPORT_STYLE}" \
+      --multi-geometry \
+      --hstore \
+      --latlong \
+      --extra-attributes \
+      --hstore-add-index \
+      --cache-strategy dense \
+      "${SPEARHEAD_IMPORT_FILE}"
+  else
+    printf "Error: Import file '%s' not found.\nAborting.\n" "${SPEARHEAD_IMPORT_FILE}"
+    exit 1
+  fi
+}

spearhead

 #!/bin/bash
 #
-# spearhead
+# spearhead: Import OpenStreetMap data into OpenBuildingMap
 
 # Copyright (C) 2021:
 #   Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentrum GFZ
@@ -19,15 +19,50 @@
 # along with this program. If not, see http://www.gnu.org/licenses/.
 
 #######################################
-# Main function of this script
+# Import other shell script(s)
+#######################################
+# shellcheck source=includes/database.sh
+source /usr/local/lib/spearhead/includes/database.sh --source-only
+# shellcheck source=includes/import.sh
+source /usr/local/lib/spearhead/includes/import.sh --source-only
+
+#######################################
+# Main function of this script, to be executed for initial import.
 # Globals:
-#   None
+#   SPEARHEAD_DATABASE_HOST
+#   SPEARHEAD_DATABASE_NAME
 # Arguments:
 #   None
 #######################################
 function main() {
-  printf "Hello world\n"
+  printf "Connecting to PostgreSQL on '%s':\n" "${SPEARHEAD_DATABASE_HOST}"
+  database::wait_for_connection
+
+  # Initiate new or reuse existing database
+  if database::execute_command "\connect ${SPEARHEAD_DATABASE_NAME}"; then
+    printf "Reuse existing database: %s\n" "${SPEARHEAD_DATABASE_NAME}"
+  else
+    database::execute_command "CREATE DATABASE ${SPEARHEAD_DATABASE_NAME};"
+    database::add_extensions
+    printf "Initiated new database: %s\n" "${SPEARHEAD_DATABASE_NAME}"
+  fi
+
+  # Import OpenStreetMap data if database is empty
+  database_exists=$(psql --host="${SPEARHEAD_DATABASE_HOST}" \
+    --username="${SPEARHEAD_DATABASE_USER}" "${SPEARHEAD_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 ${database_exists}; then
+    printf "Assuming already imported database: %s\n" "${SPEARHEAD_DATABASE_NAME}"
+  else
+    import::openstreetmap_data
+    printf "OpenStreetMap data has been imported.\n"
+  fi
 }
 
+# Start the script
+printf "\nWelcome to the OpenBuildingMap importer\n\n"
+
 # Call main function of the script
 main