fixing issue with PostGIS topology extension

environment variable DB_POSTGIS_TOPOLOGY controls creation of
'postgis_topology' extension _only_ when user selects PostGIS extension.

refs sameersbn#44

Author: Łukasz Wiecheć

README.md

@@ -200,6 +200,17 @@ docker run --name postgresql -itd \
   sameersbn/postgresql:9.4-11
 ```
 
+Additionally, creation of PostGIS topology extension can be enabled by specifying `DB_POSTGIS_TOPOLOGY=true`:
+
+
+```bash
+docker run --name postgresql -itd \
+  --env 'DB_NAME=dbname' --env 'DB_POSTGIS=true' --env DB_POSTGIS_TOPOLOGY=true \
+  sameersbn/postgresql:9.4-11
+```
+
+Note that topology extension creation can be enabled only when PostGIS extension is enabled.
+
 *By default the PostGIS extension is disabled*
 
 ## Granting user access to a database

runtime/env-defaults

@@ -20,3 +20,4 @@ DB_TEMPLATE=${DB_TEMPLATE:-template1}
 
 DB_UNACCENT=${DB_UNACCENT:-false}
 DB_POSTGIS=${DB_POSTGIS:-false}
+DB_POSTGIS_TOPOLOGY=${DB_POSTGIS_TOPOLOGY:-false}

runtime/functions

@@ -326,7 +326,10 @@ create_database() {
           if [[ ${DB_POSTGIS} == true ]]; then
             echo "‣ Loading PostGIS extension..."
             psql -U ${PG_USER} -d ${database} -c "CREATE EXTENSION IF NOT EXISTS postgis;" >/dev/null 2>&1
-            psql -U ${PG_USER} -d ${database} -c "CREATE EXTENSION IF NOT EXISTS postgis_topology;" >/dev/null 2>&1
+            if [[ ${DB_POSTGIS_TOPOLOGY} == true ]]; then
+                echo "‣ Loading PostGIS Topology extension..."
+                psql -U ${PG_USER} -d ${database} -c "CREATE EXTENSION IF NOT EXISTS postgis_topology;" >/dev/null 2>&1
+            fi
           fi
 
           if [[ -n ${DB_USER} ]]; then