Add wp-snapshots folder to make duplicator work

Dockerfile

@@ -26,6 +26,9 @@ RUN curl -L -o /app/code/disable-wordpress-core-update.zip https://downloads.wor
 # https://plugins.svn.wordpress.org/wp-mail-smtp/
 RUN curl -L -o /app/code/wp-mail-smtp.zip https://downloads.wordpress.org/plugin/wp-mail-smtp.0.10.1.zip
 
+# plugins like duplicator need wp-snapshots folder to be writeable
+RUN ln -sf /app/data/wp-snapshots /app/code/wp-snapshots
+
 RUN chown -R www-data:www-data /app/code
 
 # configure apache

start.sh

@@ -4,7 +4,7 @@ set -eu
 
 readonly WP="/app/code/wp --allow-root --skip-plugins"
 
-mkdir -p /run/wordpress/sessions
+mkdir -p /run/wordpress/sessions /app/data/wp-snapshots
 
 # Detect the wordpress prefix from existing database. This is a bit of a hack because some wordpress plugins
 # seem to leave the old wp_ tables behind.