actually work

Dockerfile

@@ -2,6 +2,7 @@ FROM sutty/monit:latest
 MAINTAINER "f <f@sutty.nl>"
 
 RUN apk add --no-cache prometheus daemonize
+COPY ./monit.conf /etc/monit.d/prometheus.conf
 COPY ./prometheusd.sh /usr/local/bin/prometheusd
 
 EXPOSE 9090

monit.conf

@@ -0,0 +1,4 @@
+check process postfix with pidfile /var/spool/postfix/pid/master.pid
+  start program = "/usr/local/bin/prometheusd start"
+   stop program = "/usr/local/bin/prometheusd stop"
+  if 5 restarts within 8 cycles then alert

prometheusd.sh

@@ -2,9 +2,24 @@
 
 pid=/tmp/prometheus.pid
 var=/var/lib/prometheus
-log=/dev/log
+
+case $1 in
+  stop)
+    test -f "${pid}" || exit 0
+
+    cat "${pid}" | xargs -r kill
+
+    rm "${pid}"
+    ;;
+  start)
+    rm -f "${pid}"
 
     chown prometheus:prometheus /var/lib/prometheus/data
+    chmod -R u=rwX,g=rX,o= /var/lib/prometheus
 
-daemonize -p "${pid}" -l "${pid}" -u prometheus -c "${var}" -a -o "${log}" -e "${log}" \
+    daemonize -p "${pid}" -l "${pid}" -u prometheus -c "${var}" \
       /usr/bin/prometheus --config.file=/etc/prometheus/prometheus.yml --storage.tsdb.path="${var}/data"
+    ;;
+esac
+
+exit $?