Add tini to handle zombies created by Nagios

Dockerfile

@@ -22,7 +22,8 @@ RUN apk add --no-cache \
     nagios-plugins-tcp \
     nagios-web \
     nrpe-plugin \
-    ssmtp && \
+    ssmtp \
+    tini && \
     chown nagios /etc/ssmtp/ssmtp.conf
 
 COPY FREE_send_notification.sh /usr/bin/FREE_send_notification.sh

entrypoint.sh

@@ -3,4 +3,4 @@
 [ -n "${MAILER_HOST}" ] && sed -r "/^mailhub=/s/.*/mailhub=${MAILER_HOST}/" /etc/ssmtp/ssmtp.conf > ~/ssmtp.conf && cat ~/ssmtp.conf > /etc/ssmtp/ssmtp.conf
 [ -n "${MAILER_REWRITEDOMAIN}" ] && sed -r "/^#?rewriteDomain=/s/.*/rewriteDomain=${MAILER_REWRITEDOMAIN}/" /etc/ssmtp/ssmtp.conf > ~/ssmtp.conf && cat ~/ssmtp.conf > /etc/ssmtp/ssmtp.conf
 
-exec $@
+exec /sbin/tini -- $@