configure logging to stdout during startup to effect mounted configs

Dockerfile

@@ -4,8 +4,8 @@ RUN apk add postfix
 
 # http://www.postfix.org/MAILLOG_README.html
 RUN postconf -F | grep -E '^postlog/unix-dgram/service = postlog$' \
-    && postconf -evv maillog_file=/dev/stdout \
     && postfix check
 
 EXPOSE 25/tcp
-CMD ["postfix", "start-fg"]
+COPY postfix.sh /
+CMD ["/postfix.sh"]

postfix.sh

@@ -0,0 +1,8 @@
+#!/bin/sh
+
+set -ex
+
+# http://www.postfix.org/MAILLOG_README.html
+postconf -e maillog_file=/dev/stdout
+
+exec postfix start-fg