add opendkim to postfix group

Author: namachan10777

opendkim/Dockerfile

@@ -1,6 +1,8 @@
 FROM ubuntu:noble
 
+ARG POSTFIX_GID=4005
 RUN apt-get update && apt-get install -y opendkim openssl
+RUN groupadd -g ${POSTFIX_GID} postfix && gpasswd -a opendkim postfix
 
 ENTRYPOINT ["/usr/sbin/opendkim"]
 CMD ["-f", "-x", "/etc/opendkim.conf"]