Add ALLOW_CORS parameter

Dockerfile

@@ -131,7 +131,8 @@ RUN mkdir /var/lib/mod_tile \
   && mkdir /var/run/renderd \
   && chown renderer /var/run/renderd
 RUN echo "LoadModule tile_module /usr/lib/apache2/modules/mod_tile.so" >> /etc/apache2/conf-available/mod_tile.conf \
-  && a2enconf mod_tile
+    && echo "LoadModule headers_module /usr/lib/apache2/modules/mod_headers.so" >> /etc/apache2/conf-available/mod_headers.conf \
+  && a2enconf mod_tile && a2enconf mod_headers
 COPY apache.conf /etc/apache2/sites-available/000-default.conf
 COPY leaflet-demo.html /var/www/html/index.html
 RUN ln -sf /proc/1/fd/1 /var/log/apache2/access.log \

README.md

@@ -79,6 +79,19 @@ docker run \
 
 This will enable a background process that automatically downloads changes from the OpenStreetMap server, filters them for the relevant region polygon you specified, updates the database and finally marks the affected tiles for rerendering.
 
+### Cross-origin resource sharing
+
+To enable the `Access-Control-Allow-Origin` header to be able to retrieve tiles from other domains, simply set the `ALLOW_CORS` variable to `1`:
+
+```
+docker run \
+    -p 80:80 \
+    -v openstreetmap-data:/var/lib/postgresql/10/main \
+    -e ALLOW_CORS=1 \
+    -d overv/openstreetmap-tile-server \
+    run
+```
+
 ## Performance tuning and tweaking
 
 Details for update procedure and invoked scripts can be found here [link](https://ircama.github.io/osm-carto-tutorials/updating-data/).

apache.conf

@@ -10,4 +10,8 @@
 
     ErrorLog ${APACHE_LOG_DIR}/error.log
     CustomLog ${APACHE_LOG_DIR}/access.log combined
+
+    <IfDefine ALLOW_CORS>
+        Header set Access-Control-Allow-Origin "*"
+    </IfDefine>
 </VirtualHost>

run.sh

@@ -69,6 +69,11 @@ if [ "$1" = "run" ]; then
     # Fix postgres data privileges
     chown postgres:postgres /var/lib/postgresql -R
 
+    # Configure Apache CORS
+    if [ "$ALLOW_CORS" == "1" ]; then
+        echo "export APACHE_ARGUMENTS='-D ALLOW_CORS'" >> /etc/apache2/envvars
+    fi
+
     # Initialize PostgreSQL and Apache
     CreatePostgressqlConfig
     service postgresql start