Add default configurations for nagios graph if the directory is empty

This is instead of updating the readme as per #147

Dockerfile

@@ -254,8 +254,12 @@ RUN echo "use_timezone=${NAGIOS_TIMEZONE}" >> ${NAGIOS_HOME}/etc/nagios.cfg
 
 RUN mkdir -p /orig/var                     && \
     mkdir -p /orig/etc                     && \
+    mkdir -p /orig/graph-etc                     && \
+    mkdir -p /orig/graph-var                     && \
     cp -Rp ${NAGIOS_HOME}/var/* /orig/var/ && \
-    cp -Rp ${NAGIOS_HOME}/etc/* /orig/etc/ 
+    cp -Rp ${NAGIOS_HOME}/etc/* /orig/etc/ && \
+    cp -Rp /opt/nagiosgraph/etc/* /orig/graph-etc && \
+    cp -Rp /opt/nagiosgraph/var/* /orig/graph-var
 
 ## Set the permissions for example config
 RUN find /opt/nagios/etc \! -user ${NAGIOS_USER} -exec chown ${NAGIOS_USER}:${NAGIOS_GROUP} '{}' + && \

overlay/usr/local/bin/start_nagios

@@ -14,6 +14,16 @@ if [ -z "$(ls -A /opt/nagios/var)" ]; then
     cp -Rp /orig/var/* /opt/nagios/var/
 fi
 
+if [ -z "$(ls -A /opt/nagiosgraph/etc)" ]; then
+    echo "Started with empty /opt/nagiosgraph/etc, copying example data in-place"
+    cp -Rp /orig/graph-etc/* /opt/nagiosgraph/etc/
+fi
+
+if [ -z "$(ls -A /opt/nagiosgraph/var)" ]; then
+    echo "Started with empty /opt/nagiosgraph/var, copying example data in-place"
+    cp -Rp /orig/graph-var/* /opt/nagiosgraph/var/
+fi
+
 if [ ! -f "${NAGIOS_HOME}/etc/htpasswd.users" ] ; then
   htpasswd -c -b -s "${NAGIOS_HOME}/etc/htpasswd.users" "${NAGIOSADMIN_USER}" "${NAGIOSADMIN_PASS}"
   chown -R ${NAGIOS_USER}.${NAGIOS_GROUP} "${NAGIOS_HOME}/etc/htpasswd.users"