coreos-home-server/service/dovecot/container/run-dovecot

#!/bin/sh
set -eu

# Prepare configuration files for environment variable substitution.
ENV_NAMES="$(env | awk -F '=' '{printf "$%s ", $1}')"
for file in /etc/dovecot/*.template; do
	envsubst "$ENV_NAMES" < "$file" > "${file%.template}"
done

# Compile Sieve scripts and ensure correct permissions.
find /etc/dovecot -name '*.sieve' -execdir sievec {} \;
find /etc/dovecot -name '*.script' -execdir chmod 0755 {} \;

# Set up environment variables for Rspamd integration.
env | awk -F '_' '$1 == "RSPAMD" {print $0}' > /etc/dovecot/rspamd.env

# Run Dovecot daemon.
exec /usr/sbin/dovecot -F