Create user for Drupalizer with custom UID and GID based on environment

Dockerfile

@@ -3,10 +3,24 @@
 FROM    savoirfairelinux/lampd
 MAINTAINER Ernesto Rodriguez Ortiz <ernesto.rodriguezortiz@savoirfairelinuc.com>
 
+# Create user used by Drupalizer tasks
+RUN useradd --home-dir /opt/init --create-home drupalizer --shell /bin/bash && passwd -d drupalizer
+
 # Create entrypoint script
-RUN mkdir -p /opt/init
 RUN echo '#!/bin/bash\n\
 \n\
+if [[ ! -z "$USER_ID" ]]\n\
+then\n\
+    which usermod 2>&1 >/dev/null && usermod -u $USER_ID drupalizer\n\
+    service apache2 reload\n\
+fi\n\
+\n\
+if [[ ! -z "$GROUP_ID" ]]\n\
+then\n\
+    which groupmod 2>&1 >/dev/null && groupmod -g $GROUP_ID drupalizer\n\
+    service apache2 reload\n\
+fi\n\
+\n\
 exec /bin/sh -c "$*"'\
 > /opt/init/init.sh && chmod a+x /opt/init/init.sh