adding arg to debian image didn't work out :(

src/debian/Containerfile

@@ -12,7 +12,6 @@ RUN rm /etc/localtime && \
     echo $TZ > /etc/timezone
 
 # Install packages
-ARG DEBIAN_FRONTEND=noninteractive
 RUN apt update -y 
 RUN apt upgrade -y
 RUN apt install -y init sudo wget nano less man-db unzip

src/mailserver/Containerfile

@@ -22,6 +22,9 @@ ARG FILESUID=5000
 ### General Setup
 ###
 
+# tell debian not to ask questions during install process
+ARG DEBIAN_FRONTEND=noninteractive
+
 # install packages we want
 RUN apt update -y && apt install -y postfix dovecot-imapd dovecot-lmtpd