Create a startup.sh script to make the quote-mangling for the crontab generation a bit more clear

Author: mwestphall

opensciencegrid/logrotate/Dockerfile

@@ -14,4 +14,5 @@ RUN yum install -y crontabs \
                    logrotate \
     && yum clean all
 
-CMD [ "sh", "-c", "echo \"$CRON_EXPR /usr/sbin/logrotate $LOGROTATE_OPTIONS $LOGROTATE_CONF\" '> /proc/$(cat /var/run/crond.pid)/fd/1 2>&1' | crontab - && crond -n"]
+COPY startup.sh /bin/
+CMD [ "/bin/startup.sh" ]

opensciencegrid/logrotate/startup.sh

@@ -0,0 +1,8 @@
+#!/bin/bash 
+
+# Create a cron file on the fly based on docker environment variables,
+# Then immediately pipe it to crontab
+echo "$CRON_EXPR /usr/sbin/logrotate $LOGROTATE_OPTIONS $LOGROTATE_CONF" '> /proc/$(cat /var/run/crond.pid)/fd/1 2>&1' | crontab - 
+
+# Start cron in non-daemon (foreground) mode
+crond -n