Using the crontab command adds the job to root's jobs. Allow cron to pick up the file automatically by not running any explicit calls.

Config/HugoExample/Dockerfile

@@ -17,9 +17,8 @@ RUN mkdir -pv /var/www/hugo/
 RUN mkdir -pv /var/www/html/
 
 # Copy Cron Job to Update Git Repo
-COPY files/hugo.crontab /etc/cron.d/hugo
+COPY files/hugo.crontab /etc/crontab
 COPY files/hugo.cronjob.sh /var/www/hugo/cronjob.sh
-RUN crontab /etc/cron.d/hugo
 
 # Hugo User Permissions
 RUN chown -Rv www-data:www-data /var/www/