modified: Dockerfile

new file:   start.sh
Added script file to start the container

Dockerfile

@@ -20,4 +20,7 @@ RUN echo http://dl-4.alpinelinux.org/alpine/edge/testing >> /etc/apk/repositorie
   rm -rf /tmp/src && \
   rm -rf /var/cache/apk/*
 
-CMD [ "/bin/sh" ]
+COPY start.sh /usr/local/bin/start.sh
+RUN chmod 755 /usr/local/bin/start.sh
+
+CMD [ "/usr/local/bin/start.sh" ]

start.sh

@@ -0,0 +1,6 @@
+#!/bin/sh
+##
+## Script to automate the copy of Sonarr databases
+##
+echo -e 'Starting the sidecar container to periodically backup the sonarr databases'
+sleep 3600