postfix

Dockerfile

@@ -1,2 +1,85 @@
+# TODO: This configuration is only really useful for sending e-mail.  It
+# receives and stores email for local users but we're not serving them
+# just yet.
 FROM sutty/monit:latest
 MAINTAINER "f <f@sutty.nl>"
+
+# Install postfix and certificates
+RUN apk add --no-cache postfix ca-certificates
+# Generate params and remove packages
+RUN install -dm 2750 -o root -g root /etc/ssl/private \
+  && apk add --no-cache gnutls-utils \
+  && certtool --generate-dh-params --outfile=/etc/ssl/private/2048.dh --bits=2048 \
+  && certtool --generate-dh-params --outfile=/etc/ssl/private/512.dh --bits=512 \
+  && apk del gnutls-utils
+# Configure postfix
+RUN postconf -e alias_maps='hash:/etc/postfix/aliases' \
+  && postconf -e transport_maps='hash:/etc/postfix/transport' \
+  && postconf -e recipient_delimiter='+' \
+  && postconf -e sendmail_path='/usr/sbin/sendmail' \
+  && postconf -e newaliases_path='/usr/bin/newaliases' \
+  && postconf -e mailq_path='/usr/bin/mailq' \
+  && postconf -e setgid_group='postdrop' \
+  && postconf -e manpage_directory='/usr/share/man' \
+  && postconf -e sample_directory='/etc/postfix/sample' \
+  && postconf -e readme_directory='/usr/share/doc/postfix' \
+  && postconf -e html_directory='no' \
+  && postconf -e soft_bounce='no' \
+  && postconf -e mydestination='$mydomain' \
+  && postconf -e inet_interfaces='all' \
+  && postconf -e local_recipient_maps='unix:passwd.byname $alias_maps' \
+  && postconf -e mynetworks_style='host' \
+  && postconf -e home_mailbox='Maildir/' \
+  && postconf -e message_size_limit=20480000 \
+  && postconf -e inet_protocols='all' \
+  && postconf -e disable_vrfy_command=yes \
+  && postconf -e smtpd_helo_required=yes \
+  && postconf -e smtpd_helo_restrictions='permit_mynetworks,permit_sasl_authenticated,reject_non_fqdn_helo_hostname,reject_invalid_helo_hostname,reject_unknown_helo_hostname,permit' \
+  && postconf -e smtpd_recipient_restrictions='reject_non_fqdn_recipient,reject_unknown_recipient_domain,permit_mynetworks,permit_sasl_authenticated,reject_unauth_destination,reject_non_fqdn_sender,reject_unlisted_recipient' \
+  && postconf -e smtpd_sender_restrictions='permit_mynetworks,permit_sasl_authenticated,reject_non_fqdn_sender,reject_unknown_sender_domain,permit' \
+  && postconf -e smtpd_data_restrictions='reject_unauth_pipelining' \
+  && postconf -e smtpd_client_restrictions='permit_mynetworks,permit_sasl_authenticated' \
+  && postconf -e smtpd_relay_restrictions='permit_mynetworks,permit_sasl_authenticated,reject_unauth_destination' \
+  && postconf -e smtpd_use_tls='yes' \
+  && postconf -e smtpd_tls_auth_only='yes' \
+  && postconf -e smtp_use_tls='yes' \
+  && postconf -e smtp_tls_note_starttls_offer='yes' \
+  && postconf -e smtpd_tls_CApath='/etc/ssl/certs' \
+  && postconf -e tls_random_source='dev:/dev/urandom' \
+  && postconf -e smtpd_tls_dh1024_param_file='/etc/ssl/private/2048.dh' \
+  && postconf -e smtpd_tls_dh512_param_file='/etc/ssl/private/512.dh' \
+  && postconf -e tls_preempt_cipherlist='yes' \
+  && postconf -e smtpd_tls_security_level='may' \
+  && postconf -e smtpd_tls_eecdh_grade='strong' \
+  && postconf -e smtpd_tls_mandatory_ciphers='high' \
+  && postconf -e smtpd_tls_ciphers='medium' \
+  && postconf -e smtpd_tls_exclude_ciphers='aNULL,MD5,DES,3DES,DES-CBC3-SHA,RC4-SHA,AES256-SHA,AES128-SHA,eNULL,EXPORT,RC4,PSK,aECDH,EDH-DSS-DES-CBC3-SHA,EDH-RSA-DES-CDC3-SHA,KRB5-DE5,CBC3-SHA' \
+  && postconf -e smtpd_tls_mandatory_protocols='TLSv1' \
+  && postconf -e smtp_tls_ciphers='$smtpd_tls_ciphers' \
+  && postconf -e smtp_tls_mandatory_ciphers='$smtpd_tls_mandatory_ciphers' \
+  && postconf -e smtp_tls_protocols='!SSLv2,!SSLv3,TLSv1' \
+  && postconf -e smtpd_tls_loglevel='0' \
+  && postconf -e smtpd_tls_received_header='yes' \
+  && postconf -e smtpd_tls_session_cache_timeout='3600s' \
+  && postconf -e smtp_destination_concurrency_limit=2 \
+  && postconf -e smtp_destination_rate_delay=1s \
+  && postconf -e smtp_extra_recipient_limit=10 \
+  && postconf -e append_dot_mydomain=yes \
+  && postconf -e masquerade_domains='$mydomain'
+RUN newaliases
+RUN postmap /etc/postfix/transport
+
+# Enable service
+COPY ./monit.conf /etc/monit.d/postfix.conf
+COPY ./postfix.sh /usr/local/bin/postfix
+RUN chmod 755 /usr/local/bin/postfix
+
+# Check config
+RUN monit -t
+
+# Save email for later!
+VOLUME "/var/spool/postfix"
+VOLUME "/home"
+
+# Port
+EXPOSE 25

monit.conf

@@ -0,0 +1,5 @@
+check process postfix with pidfile /var/spool/postfix/pid/master.pid
+  start program = "/usr/local/bin/postfix"
+  stop  program = "/usr/sbin/postfix stop"
+  if 5 restarts within 8 cycles then alert
+  if failed port 25 protocol smtp for 3 times within 5 cycles then restart

postfix.sh

@@ -0,0 +1,23 @@
+#!/bin/sh
+
+# Reconfigure postfix according to environment
+postconf -e myhostname="${SUTTY}"
+postconf -e mydomain="${SUTTY}"
+postconf -e smtpd_tls_key_file="/etc/letsencrypt/live/${SUTTY}/privkey.pem"
+postconf -e smtpd_tls_cert_file="/etc/letsencrypt/live/${SUTTY}/fullchain.pem"
+postconf -e mynetworks="127.0.0.0/8 [::1]/128 `ip route | grep -v default | cut -d " " -f 1`"
+
+# Recreate users from ~
+for home in /home/*; do
+  user="${home##*/}"
+  test "${user}" = "*" && continue
+
+  uid="$(stat -c %u "${home}")"
+
+  # Skip if it already exists
+  getent passwd ${user} >/dev/null && continue
+
+  adduser -h ${home} -s /bin/false -G users -D -H -u ${uid} ${user}
+done
+
+exec /usr/sbin/postfix start