[mailcow] Use ofelia instead of cron daemons (wip: remove init systems)

data/Dockerfiles/dovecot/Dockerfile

@@ -4,6 +4,7 @@ LABEL maintainer "Andre Peters <andre.peters@servercow.de>"
 ARG DEBIAN_FRONTEND=noninteractive
 ARG DOVECOT=2.3.14
 ENV LC_ALL C
+ENV GOSU_VERSION 1.12
 
 # Add groups and users before installing Dovecot to not break compatibility
 RUN groupadd -g 5000 vmail \
@@ -20,7 +21,6 @@ RUN groupadd -g 5000 vmail \
   apt-transport-https \
   ca-certificates \
   cpanminus \
-  cron \
   curl \
   dnsutils \
   dirmngr \
@@ -82,6 +82,11 @@ RUN groupadd -g 5000 vmail \
   syslog-ng \
   syslog-ng-core \
   syslog-ng-mod-redis \
+  wget \
+  && dpkgArch="$(dpkg --print-architecture | awk -F- '{ print $NF }')" \
+  && wget -O /usr/local/bin/gosu "https://github.com/tianon/gosu/releases/download/$GOSU_VERSION/gosu-$dpkgArch" \
+  && chmod +x /usr/local/bin/gosu \
+  && gosu nobody true \
   && apt-key adv --fetch-keys https://repo.dovecot.org/DOVECOT-REPO-GPG \
   && echo "deb https://repo.dovecot.org/ce-${DOVECOT}/debian/buster buster main" > /etc/apt/sources.list.d/dovecot.list \
   && apt-get update \
@@ -100,7 +105,7 @@ RUN groupadd -g 5000 vmail \
   && apt-get autoremove --purge -y \
   && apt-get autoclean \
   && rm -rf /var/lib/apt/lists/* \
-  && rm -rf /tmp/* /var/tmp/* /etc/cron.daily/* /root/.cache/
+  && rm -rf /tmp/* /var/tmp/* /root/.cache/
 
 COPY trim_logs.sh /usr/local/bin/trim_logs.sh
 COPY clean_q_aged.sh /usr/local/bin/clean_q_aged.sh
@@ -108,7 +113,7 @@ COPY syslog-ng.conf /etc/syslog-ng/syslog-ng.conf
 COPY syslog-ng-redis_slave.conf /etc/syslog-ng/syslog-ng-redis_slave.conf
 COPY imapsync /usr/local/bin/imapsync
 COPY postlogin.sh /usr/local/bin/postlogin.sh
-COPY imapsync_cron.pl /usr/local/bin/imapsync_cron.pl
+COPY imapsync_runner.pl /usr/local/bin/imapsync_runner.pl
 COPY report-spam.sieve /usr/lib/dovecot/sieve/report-spam.sieve
 COPY report-ham.sieve /usr/lib/dovecot/sieve/report-ham.sieve
 COPY rspamd-pipe-ham /usr/lib/dovecot/sieve/rspamd-pipe-ham