Upgrade container to alpine 3.15 with no monit

Dockerfile

@@ -1,13 +1,14 @@
-FROM rawmind/alpine-monit:5.25-3
+FROM alpine:3.15
-MAINTAINER Fabio Rauber <fabiorauber@gmail.com>
+LABEL MAINTAINER="Fabio Rauber <fabiorauber@gmail.com>"
 
-RUN apk add --no-cache bash postfix postfix-pcre rsyslog
+RUN apk add --no-cache bash postfix postfix-pcre 
 
 COPY conf /etc/postfix
-COPY rsyslog.conf /etc/rsyslog.conf
-
-COPY monit-service.conf /opt/monit/etc/conf.d 
 
 VOLUME ["/var/spool/postfix"]
 
+ENTRYPOINT ["etc/postfix/postfix-service.sh"]
+
+CMD [ "start" ]
+
 EXPOSE 25

conf/main.cf

@@ -55,3 +55,4 @@ smtpd_recipient_restrictions =
 ###############
 # Extra Settings
 ###############
+maillog_file = /dev/stdout

conf/master.cf

@@ -40,3 +40,4 @@ discard   unix  -       -       n       -       -       discard
 lmtp      unix  -       -       n       -       -       lmtp
 anvil     unix  -       -       n       -       1       anvil
 scache    unix  -       -       n       -       1       scache
+postlog   unix-dgram n  -       n       -       1       postlogd

conf/postfix-service.sh

@@ -38,10 +38,8 @@ function serviceStart {
   serviceConf
   # Actually run Postfix
   log "[ Starting Postfix... ]"
-  rm -f /var/run/rsyslogd.pid
+  nohup /usr/sbin/postfix start-fg &
-  nohup /usr/lib/postfix/master &
   echo $! > /var/run/postfix.pid
-  nohup rsyslogd -n &
 }
 
 function serviceStop {
@@ -53,10 +51,10 @@ function serviceRestart {
   log "[ Restarting Postfix... ]"
   serviceStop
   serviceStart
-  /opt/monit/bin/monit reload
 }
 
 export DOMAIN=${DOMAIN:-"localhost"}
+export HOSTNAME=${HOSTNAME:-"localhost"}
 export MESSAGE_SIZE_LIMIT=${MESSAGE_SIZE_LIMIT:-"50000000"}
 export RELAYNETS=${RELAYNETS:-""}
 export RELAYHOST=${RELAYHOST:-""}
@@ -73,4 +71,4 @@ case "$1" in
   ;;
   *) echo "Usage: $0 restart|start|stop"
   ;;
-esac
+esac

docker-compose.yml

@@ -0,0 +1,8 @@
+version: '2'
+services:
+  postfix:
+    build: .
+    ports:
+      - 25
+    entrypoint: /bin/bash
+    tty: true

monit-service.conf

@@ -1,4 +0,0 @@
-check process master with pidfile /var/run/postfix.pid
-  start program = "/etc/postfix/postfix-service.sh start"
-  stop program = "/etc/postfix/postfix-service.sh stop"
-  if failed port 25 type tcp for 5 cycles then exec "/opt/monit/bin/monit quit"