Added cron into docker

Dockerfile

@@ -6,9 +6,19 @@ ENV HOME="/config"
 EXPOSE 9443
 
 RUN apt-get update \
-    && DEBIAN_FRONTEND=noninteractive apt-get install -y libmojolicious-perl curl \
+    && DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends cron libmojolicious-perl curl \
     && rm -rf /var/cache/apt/archives /var/lib/apt/lists/*
 
+RUN curl -sSL https://github.com/just-containers/s6-overlay/releases/download/v${S6_OVERLAY_VERSION}/s6-overlay-noarch.tar.xz -o /tmp/s6-overlay-noarch.tar.xz
+    && tar -C / -Jxpf /tmp/s6-overlay-noarch.tar.xz
+    && curl -sSL https://github.com/just-containers/s6-overlay/releases/download/v${S6_OVERLAY_VERSION}/s6-overlay-x86_64.tar.xz /tmp/s6-overlay-x86_64.tar.xz
+    && tar -C / -Jxpf /tmp/s6-overlay-x86_64.tar.xz
+    && rm /tmp/s6-overlay-noarch.tar.xz /tmp/s6-overlay-x86_64.tar.xz
+
+COPY ./services.d /etc/services.d
+
+ENTRYPOINT ["/init"]
+
 COPY acmeproxy.pl /app/acmeproxy.pl
 
 CMD [ "perl", "/app/acmeproxy.pl" ]

docker/services.d/cron/run

@@ -0,0 +1,3 @@
+#!/usr/bin/with-contenv sh
+
+exec cron -f