initial commit

Dockerfile

+FROM alpine:latest
+MAINTAINER Fabio Montefuscolo <fabio.montefuscolo@gmail.com>
+
+RUN apk update && \
+    apk add dcron && \
+    rm -rf /var/cache/apk/*
+
+VOLUME [                        \
+        "/etc/periodic/15min",  \
+        "/etc/periodic/hourly", \
+        "/etc/periodic/daily",  \
+        "/etc/periodic/weekly", \
+        "/etc/periodic/monthly" \
+    ]
+
+COPY entrypoint.sh /entrypoint.sh
+ENTRYPOINT ["/entrypoint.sh"]
+
+CMD [ "crond", "-d", "-l5" ]
+

entrypoint.sh

+#!/bin/sh
+
+DAEMON=crond
+
+stop() {
+    echo "Received SIGINT or SIGTERM. Shutting down $DAEMON"
+    pid=$(cat /var/run/$DAEMON/$DAEMON.pid)
+    kill -SIGTERM "${pid}"
+    wait "${pid}"
+    echo "Done."
+}
+
+echo "Running $@"
+if [ "$(basename $1)" == "$DAEMON" ]; then
+    trap stop SIGINT SIGTERM
+    $@ &
+    pid="$!"
+    mkdir -p /var/run/$DAEMON && echo "${pid}" > /var/run/$DAEMON/$DAEMON.pid
+    wait "${pid}" && exit $?
+else
+    exec "$@"
+fi
+