1. manymanyuni

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    manymanyuni
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+Postfix の Docker を作成する。
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+Postfix の SMTPS 環境が必要になった際に Docker を作成したので、メモ程度でそれを書いておきます。
+(詳しく言うと、TLS 1.2 のみ受け付ける Postfix が必要でした)
+ベースイメージとして CentOS 6.9 の ssh を root/password で接続できるようにしたものを使います。
+
+本記事とは関係ないですが、SQL Server on Linux 2017 の Docker を作成していた際に、以下のタイムゾーンの設定で
+RUN ln -sf /usr/share/zoneinfo/Asia/Tokyo /etc/localtime
+の部分を、
+RUN ln -sf /usr/share/zoneinfo/Japan /etc/localtime
+にしてしまっていました。違いはよく分かっていないですが、その結果 SQL Server on Linux 2017 のタイムゾーンが UTC になってしまう経験があり、ln -sf /usr/share/zoneinfo/Asia/Tokyo /etc/localtime にすると無事 Asia/Tokyo で認識されました。
+
+この記事だと CentOS 6.9 を使っていますが、CentOS 7 系でタイムゾーンを設定する際には timedatectl を使えばいいんですが、docker image build 時には使えないので上記のように ln -sf して設定したのですが、zoneinfo/Asia/Tokyo を使うのと zoneinfo/Japan を使うのとでは、timedatectl の結果に差がありました。
+
+* ln -sf /usr/share/zoneinfo/Japan /etc/localtime の場合
+
+```shell:timedatectl
+ Local time: Wed 2018-04-11 17:58:57 JST
+ Universal time: Wed 2018-04-11 08:58:57 UTC
+ RTC time: Wed 2018-04-11 08:58:57
+ Time zone: - (JST, +0900)
+ NTP enabled: n/a
+NTP synchronized: yes
+ RTC in local TZ: no
+ DST active: n/a
+```
+Time zone の行がポイントです。うろ覚えなので実際の表示はハイフン(-)ではなかったかもです。(none とか空白だったかも?)
+
+* ln -sf /usr/share/zoneinfo/Asia/Tokyo /etc/localtime の場合
+
+```shell:timedatectl
+ Local time: Wed 2018-04-11 18:00:05 JST
+ Universal time: Wed 2018-04-11 09:00:05 UTC
+ RTC time: Wed 2018-04-11 09:00:05
+ Time zone: Asia/Tokyo (JST, +0900)
+ NTP enabled: n/a
+NTP synchronized: yes
+ RTC in local TZ: no
+ DST active: n/a
+```
+zoneinfo/Asia/Tokyo を使うようにすると、このように表示され、SQL Server on Linux 2017 も JST で動くようになりました。
+よく分かりませんが、検索すると、タイムゾーンを設定するのに zoneinfo/Japan を使ってる方と zoneinfo/Asia/Tokyo を使っている方の両方が引っかかるのですが、zoneinfo/Asia/Tokyo を使う方がいいのかも知れません。
+※ timedatectl set-timezone が使えればいいんですが、docker image build 時には使えないので・・・。
+
+という訳で長い脱線でしたが、Postfix の Docker の話に戻ります。
+まずはベースイメージとして利用する CentOS 6.9 の Docker から。
+
+```dockerfile:Dockerfile
+FROM centos:centos6.9
+
+EXPOSE 22
+ENV DEBIAN_FRONTEND noninteractive
+
+# yum
+RUN yum -y update && yum clean all
+
+# locale
+RUN yum reinstall -y glibc-common
+RUN localedef -i ja_JP -f UTF-8 ja_JP.utf8
+RUN touch /etc/sysconfig/i18n
+RUN echo 'LANG="ja_JP.UTF-8"' >> /etc/sysconfig/i18n
+ENV LANG ja_JP.UTF-8
+ENV LC_ALL ja_JP.UTF-8
+ENV LANGUAGE ja_JP:ja
+
+# timezone
+RUN yum install -y tzdata
+RUN echo 'ZONE="Asia/Tokyo"' > /etc/sysconfig/clock
+RUN echo 'UTC=false' >> /etc/sysconfig/clock
+RUN ln -sf /usr/share/zoneinfo/Asia/Tokyo /etc/localtime
+
+# tools
+RUN yum groupinstall -y 'Development Tools'
+RUN yum install -y --enablerepo centosplus wget curl vim emacs tar unzip mlocate perl ssh openssh-server openssl-devel
+
+# root passwd
+RUN bash -c 'echo "root:password" | chpasswd'
+
+# ssh
+RUN sed -i -e "s/#PasswordAuthentication yes/PasswordAuthentication yes/g" /etc/ssh/sshd_config
+RUN sed -i -e "s/#PermitRootLogin yes/PermitRootLogin yes/g" /etc/ssh/sshd_config
+RUN sed -i -e "s/UsePAM yes/UsePAM no/g" /etc/ssh/sshd_config
+
+RUN updatedb
+
+CMD /etc/init.d/sshd restart && /bin/bash
+```
+
+locate コマンドが便利なので Dockerfile の最後に必ず入れるようにしてます。
+やってるのはロケールとタイムゾーンと ssh を設定しているだけです。
+
+次は Postfix の Docker です。
+
+```dockerfile:Dockerfile
+FROM mycentos:6.9
+
+EXPOSE 25 465 587
+
+RUN yum -y update && yum clean all
+RUN yum -y upgrade && yum -y update && yum clean all
+
+ADD run.sh /run.sh
+RUN chmod +x /run.sh
+
+# setup_postfix
+ADD setup_postfix.sh /setup_postfix.sh
+RUN chmod +x /setup_postfix.sh
+RUN /setup_postfix.sh
+RUN rm -f /setup_postfix.sh
+
+ADD main.cf /etc/postfix/main.cf
+ADD master.cf /etc/postfix/master.cf
+
+RUN updatedb
+
+CMD /run.sh
+```
+
+```shell:run.sh
+#!/bin/bash
+
+service sshd restart
+
+echo "Downloading latest cert..."
+curl https://mywebserver/ssl/example.com.crt > /etc/postfix/example.com.crt
+curl https//mywebserver/ssl/example.com.key > /etc/postfix/example.com.key
+
+sed -i -e "s/FIXME/${1}/g" /etc/postfix/main.cf
+
+IP=$(ip addr show eth0 | perl -n -e 'if (m/inet ([\d\.]+)/g) { print $1 }')
+echo -e "${IP}\t${1}" >> /etc/hosts
+
+service postfix restart
+
+/bin/bash
+```
+/etc/postfix 配下に SSL 証明書を置くようにしています。
+Let's encrypt の証明書の有効期限は 90 日なので、有効期限が切れる度に docker image build をするのも嫌なので、どこかの Web サーバに最新の証明書を置いてそれを docker run 時にダウンロードするようにしています。
+手抜きなんですが、もう少し凝った事をするのであれば Let's encrypt の certbot-auto で renew するようにするといいかもしれません。
+
+```shell:setup_postfix.sh
+#!/bin/sh
+
+yum install -y postfix
+
+cp /etc/postfix/main.cf /etc/postfix/main.cf.org
+cp /etc/postfix/master.cf /etc/postfix/master.cf.org
+```
+
+Postfix のインストール処理です。
+yum install するだけで入るので大した処理はないです。
+/etc/postfix/main.cf と /etc/postfix/master.cf を修正するので、オリジナルの設定を残すようにコピーだけしています。
+
+```config:main.cf
+# Global Postfix configuration file. This file lists only a subset
+# of all parameters. For the syntax, and for a complete parameter
+# list, see the postconf(5) manual page (command: "man 5 postconf").
+#
+# For common configuration examples, see BASIC_CONFIGURATION_README
+# and STANDARD_CONFIGURATION_README. To find these documents, use
+# the command "postconf html_directory readme_directory", or go to
+# http://www.postfix.org/.
+#
+# For best results, change no more than 2-3 parameters at a time,
+# and test if Postfix still works after every change.
+
+# SOFT BOUNCE
+#
+# The soft_bounce parameter provides a limited safety net for
+# testing. When soft_bounce is enabled, mail will remain queued that
+# would otherwise bounce. This parameter disables locally-generated
+# bounces, and prevents the SMTP server from rejecting mail permanently
+# (by changing 5xx replies into 4xx replies). However, soft_bounce
+# is no cure for address rewriting mistakes or mail routing mistakes.
+#
+#soft_bounce = no
+
+# LOCAL PATHNAME INFORMATION
+#
+# The queue_directory specifies the location of the Postfix queue.
+# This is also the root directory of Postfix daemons that run chrooted.
+# See the files in examples/chroot-setup for setting up Postfix chroot
+# environments on different UNIX systems.
+#
+queue_directory = /var/spool/postfix
+
+# The command_directory parameter specifies the location of all
+# postXXX commands.
+#
+command_directory = /usr/sbin
+
+# The daemon_directory parameter specifies the location of all Postfix
+# daemon programs (i.e. programs listed in the master.cf file). This
+# directory must be owned by root.
+#
+daemon_directory = /usr/libexec/postfix
+
+# The data_directory parameter specifies the location of Postfix-writable
+# data files (caches, random numbers). This directory must be owned
+# by the mail_owner account (see below).
+#
+data_directory = /var/lib/postfix
+
+# QUEUE AND PROCESS OWNERSHIP
+#
+# The mail_owner parameter specifies the owner of the Postfix queue
+# and of most Postfix daemon processes. Specify the name of a user
+# account THAT DOES NOT SHARE ITS USER OR GROUP ID WITH OTHER ACCOUNTS
+# AND THAT OWNS NO OTHER FILES OR PROCESSES ON THE SYSTEM. In
+# particular, don't specify nobody or daemon. PLEASE USE A DEDICATED
+# USER.
+#
+mail_owner = postfix
+
+# The default_privs parameter specifies the default rights used by
+# the local delivery agent for delivery to external file or command.
+# These rights are used in the absence of a recipient user context.
+# DO NOT SPECIFY A PRIVILEGED USER OR THE POSTFIX OWNER.
+#
+#default_privs = nobody
+
+# INTERNET HOST AND DOMAIN NAMES
+#
+# The myhostname parameter specifies the internet hostname of this
+# mail system. The default is to use the fully-qualified domain name
+# from gethostname(). $myhostname is used as a default value for many
+# other configuration parameters.
+#
+#myhostname = host.domain.tld
+#myhostname = virtual.domain.tld
+myhostname = FIXME
+
+# The mydomain parameter specifies the local internet domain name.
+# The default is to use $myhostname minus the first component.
+# $mydomain is used as a default value for many other configuration
+# parameters.
+#
+mydomain = example.com
+
+# SENDING MAIL
+#
+# The myorigin parameter specifies the domain that locally-posted
+# mail appears to come from. The default is to append $myhostname,
+# which is fine for small sites. If you run a domain with multiple
+# machines, you should (1) change this to $mydomain and (2) set up
+# a domain-wide alias database that aliases each user to
+# user@that.users.mailhost.
+#
+# For the sake of consistency between sender and recipient addresses,
+# myorigin also specifies the default domain name that is appended
+# to recipient addresses that have no @domain part.
+#
+#myorigin = $myhostname
+#myorigin = $mydomain
+myorigin = $myhostname
+
+# RECEIVING MAIL
+
+# The inet_interfaces parameter specifies the network interface
+# addresses that this mail system receives mail on. By default,
+# the software claims all active interfaces on the machine. The
+# parameter also controls delivery of mail to user@[ip.address].
+#
+# See also the proxy_interfaces parameter, for network addresses that
+# are forwarded to us via a proxy or network address translator.
+#
+# Note: you need to stop/start Postfix when this parameter changes.
+#
+#inet_interfaces = all
+#inet_interfaces = $myhostname
+#inet_interfaces = $myhostname, localhost
+# inet_interfaces = localhost
+inet_interfaces = $myhostname
+
+# Enable IPv4, and IPv6 if supported
+inet_protocols = ipv4
+
+# The proxy_interfaces parameter specifies the network interface
+# addresses that this mail system receives mail on by way of a
+# proxy or network address translation unit. This setting extends
+# the address list specified with the inet_interfaces parameter.
+#
+# You must specify your proxy/NAT addresses when your system is a
+# backup MX host for other domains, otherwise mail delivery loops
+# will happen when the primary MX host is down.
+#
+#proxy_interfaces =
+#proxy_interfaces = 1.2.3.4
+
+# The mydestination parameter specifies the list of domains that this
+# machine considers itself the final destination for.
+#
+# These domains are routed to the delivery agent specified with the
+# local_transport parameter setting. By default, that is the UNIX
+# compatible delivery agent that lookups all recipients in /etc/passwd
+# and /etc/aliases or their equivalent.
+#
+# The default is $myhostname + localhost.$mydomain. On a mail domain
+# gateway, you should also include $mydomain.
+#
+# Do not specify the names of virtual domains - those domains are
+# specified elsewhere (see VIRTUAL_README).
+#
+# Do not specify the names of domains that this machine is backup MX
+# host for. Specify those names via the relay_domains settings for
+# the SMTP server, or use permit_mx_backup if you are lazy (see
+# STANDARD_CONFIGURATION_README).
+#
+# The local machine is always the final destination for mail addressed
+# to user@[the.net.work.address] of an interface that the mail system
+# receives mail on (see the inet_interfaces parameter).
+#
+# Specify a list of host or domain names, /file/name or type:table
+# patterns, separated by commas and/or whitespace. A /file/name
+# pattern is replaced by its contents; a type:table is matched when
+# a name matches a lookup key (the right-hand side is ignored).
+# Continue long lines by starting the next line with whitespace.
+#
+# See also below, section "REJECTING MAIL FOR UNKNOWN LOCAL USERS".
+#
+mydestination = $myhostname, localhost.$mydomain, localhost
+#mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain
+#mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain,
+# mail.$mydomain, www.$mydomain, ftp.$mydomain
+
+# REJECTING MAIL FOR UNKNOWN LOCAL USERS
+#
+# The local_recipient_maps parameter specifies optional lookup tables
+# with all names or addresses of users that are local with respect
+# to $mydestination, $inet_interfaces or $proxy_interfaces.
+#
+# If this parameter is defined, then the SMTP server will reject
+# mail for unknown local users. This parameter is defined by default.
+#
+# To turn off local recipient checking in the SMTP server, specify
+# local_recipient_maps = (i.e. empty).
+#
+# The default setting assumes that you use the default Postfix local
+# delivery agent for local delivery. You need to update the
+# local_recipient_maps setting if:
+#
+# - You define $mydestination domain recipients in files other than
+# /etc/passwd, /etc/aliases, or the $virtual_alias_maps files.
+# For example, you define $mydestination domain recipients in
+# the $virtual_mailbox_maps files.
+#
+# - You redefine the local delivery agent in master.cf.
+#
+# - You redefine the "local_transport" setting in main.cf.
+#
+# - You use the "luser_relay", "mailbox_transport", or "fallback_transport"
+# feature of the Postfix local delivery agent (see local(8)).
+#
+# Details are described in the LOCAL_RECIPIENT_README file.
+#
+# Beware: if the Postfix SMTP server runs chrooted, you probably have
+# to access the passwd file via the proxymap service, in order to
+# overcome chroot restrictions. The alternative, having a copy of
+# the system passwd file in the chroot jail is just not practical.
+#
+# The right-hand side of the lookup tables is conveniently ignored.
+# In the left-hand side, specify a bare username, an @domain.tld
+# wild-card, or specify a user@domain.tld address.
+#
+#local_recipient_maps = unix:passwd.byname $alias_maps
+#local_recipient_maps = proxy:unix:passwd.byname $alias_maps
+#local_recipient_maps =
+
+# The unknown_local_recipient_reject_code specifies the SMTP server
+# response code when a recipient domain matches $mydestination or
+# ${proxy,inet}_interfaces, while $local_recipient_maps is non-empty
+# and the recipient address or address local-part is not found.
+#
+# The default setting is 550 (reject mail) but it is safer to start
+# with 450 (try again later) until you are certain that your
+# local_recipient_maps settings are OK.
+#
+unknown_local_recipient_reject_code = 550
+
+# TRUST AND RELAY CONTROL
+
+# The mynetworks parameter specifies the list of "trusted" SMTP
+# clients that have more privileges than "strangers".
+#
+# In particular, "trusted" SMTP clients are allowed to relay mail
+# through Postfix. See the smtpd_recipient_restrictions parameter
+# in postconf(5).
+#
+# You can specify the list of "trusted" network addresses by hand
+# or you can let Postfix do it for you (which is the default).
+#
+# By default (mynetworks_style = subnet), Postfix "trusts" SMTP
+# clients in the same IP subnetworks as the local machine.
+# On Linux, this does works correctly only with interfaces specified
+# with the "ifconfig" command.
+#
+# Specify "mynetworks_style = class" when Postfix should "trust" SMTP
+# clients in the same IP class A/B/C networks as the local machine.
+# Don't do this with a dialup site - it would cause Postfix to "trust"
+# your entire provider's network. Instead, specify an explicit
+# mynetworks list by hand, as described below.
+#
+# Specify "mynetworks_style = host" when Postfix should "trust"
+# only the local machine.
+#
+#mynetworks_style = class
+#mynetworks_style = subnet
+#mynetworks_style = host
+
+# Alternatively, you can specify the mynetworks list by hand, in
+# which case Postfix ignores the mynetworks_style setting.
+#
+# Specify an explicit list of network/netmask patterns, where the
+# mask specifies the number of bits in the network part of a host
+# address.
+#
+# You can also specify the absolute pathname of a pattern file instead
+# of listing the patterns here. Specify type:table for table-based lookups
+# (the value on the table right-hand side is not used).
+#
+#mynetworks = 168.100.189.0/28, 127.0.0.0/8
+#mynetworks = $config_directory/mynetworks
+#mynetworks = hash:/etc/postfix/network_table
+
+# The relay_domains parameter restricts what destinations this system will
+# relay mail to. See the smtpd_recipient_restrictions description in
+# postconf(5) for detailed information.
+#
+# By default, Postfix relays mail
+# - from "trusted" clients (IP address matches $mynetworks) to any destination,
+# - from "untrusted" clients to destinations that match $relay_domains or
+# subdomains thereof, except addresses with sender-specified routing.
+# The default relay_domains value is $mydestination.
+#
+# In addition to the above, the Postfix SMTP server by default accepts mail
+# that Postfix is final destination for:
+# - destinations that match $inet_interfaces or $proxy_interfaces,
+# - destinations that match $mydestination
+# - destinations that match $virtual_alias_domains,
+# - destinations that match $virtual_mailbox_domains.
+# These destinations do not need to be listed in $relay_domains.
+#
+# Specify a list of hosts or domains, /file/name patterns or type:name
+# lookup tables, separated by commas and/or whitespace. Continue
+# long lines by starting the next line with whitespace. A file name
+# is replaced by its contents; a type:name table is matched when a
+# (parent) domain appears as lookup key.
+#
+# NOTE: Postfix will not automatically forward mail for domains that
+# list this system as their primary or backup MX host. See the
+# permit_mx_backup restriction description in postconf(5).
+#
+#relay_domains = $mydestination
+
+# INTERNET OR INTRANET
+
+# The relayhost parameter specifies the default host to send mail to
+# when no entry is matched in the optional transport(5) table. When
+# no relayhost is given, mail is routed directly to the destination.
+#
+# On an intranet, specify the organizational domain name. If your
+# internal DNS uses no MX records, specify the name of the intranet
+# gateway host instead.
+#
+# In the case of SMTP, specify a domain, host, host:port, [host]:port,
+# [address] or [address]:port; the form [host] turns off MX lookups.
+#
+# If you're connected via UUCP, see also the default_transport parameter.
+#
+#relayhost = $mydomain
+#relayhost = [gateway.my.domain]
+#relayhost = [mailserver.isp.tld]
+#relayhost = uucphost
+#relayhost = [an.ip.add.ress]
+
+# REJECTING UNKNOWN RELAY USERS
+#
+# The relay_recipient_maps parameter specifies optional lookup tables
+# with all addresses in the domains that match $relay_domains.
+#
+# If this parameter is defined, then the SMTP server will reject
+# mail for unknown relay users. This feature is off by default.
+#
+# The right-hand side of the lookup tables is conveniently ignored.
+# In the left-hand side, specify an @domain.tld wild-card, or specify
+# a user@domain.tld address.
+#
+#relay_recipient_maps = hash:/etc/postfix/relay_recipients
+
+# INPUT RATE CONTROL
+#
+# The in_flow_delay configuration parameter implements mail input
+# flow control. This feature is turned on by default, although it
+# still needs further development (it's disabled on SCO UNIX due
+# to an SCO bug).
+#
+# A Postfix process will pause for $in_flow_delay seconds before
+# accepting a new message, when the message arrival rate exceeds the
+# message delivery rate. With the default 100 SMTP server process
+# limit, this limits the mail inflow to 100 messages a second more
+# than the number of messages delivered per second.
+#
+# Specify 0 to disable the feature. Valid delays are 0..10.
+#
+#in_flow_delay = 1s
+
+# ADDRESS REWRITING
+#
+# The ADDRESS_REWRITING_README document gives information about
+# address masquerading or other forms of address rewriting including
+# username->Firstname.Lastname mapping.
+
+# ADDRESS REDIRECTION (VIRTUAL DOMAIN)
+#
+# The VIRTUAL_README document gives information about the many forms
+# of domain hosting that Postfix supports.
+
+# "USER HAS MOVED" BOUNCE MESSAGES
+#
+# See the discussion in the ADDRESS_REWRITING_README document.
+
+# TRANSPORT MAP
+#
+# See the discussion in the ADDRESS_REWRITING_README document.
+
+# ALIAS DATABASE
+#
+# The alias_maps parameter specifies the list of alias databases used
+# by the local delivery agent. The default list is system dependent.
+#
+# On systems with NIS, the default is to search the local alias
+# database, then the NIS alias database. See aliases(5) for syntax
+# details.
+#
+# If you change the alias database, run "postalias /etc/aliases" (or
+# wherever your system stores the mail alias file), or simply run
+# "newaliases" to build the necessary DBM or DB file.
+#
+# It will take a minute or so before changes become visible. Use
+# "postfix reload" to eliminate the delay.
+#
+#alias_maps = dbm:/etc/aliases
+alias_maps = hash:/etc/aliases
+#alias_maps = hash:/etc/aliases, nis:mail.aliases
+#alias_maps = netinfo:/aliases
+
+# The alias_database parameter specifies the alias database(s) that
+# are built with "newaliases" or "sendmail -bi". This is a separate
+# configuration parameter, because alias_maps (see above) may specify
+# tables that are not necessarily all under control by Postfix.
+#
+#alias_database = dbm:/etc/aliases
+#alias_database = dbm:/etc/mail/aliases
+alias_database = hash:/etc/aliases
+#alias_database = hash:/etc/aliases, hash:/opt/majordomo/aliases
+
+# ADDRESS EXTENSIONS (e.g., user+foo)
+#
+# The recipient_delimiter parameter specifies the separator between
+# user names and address extensions (user+foo). See canonical(5),
+# local(8), relocated(5) and virtual(5) for the effects this has on
+# aliases, canonical, virtual, relocated and .forward file lookups.
+# Basically, the software tries user+foo and .forward+foo before
+# trying user and .forward.
+#
+#recipient_delimiter = +
+
+# DELIVERY TO MAILBOX
+#
+# The home_mailbox parameter specifies the optional pathname of a
+# mailbox file relative to a user's home directory. The default
+# mailbox file is /var/spool/mail/user or /var/mail/user. Specify
+# "Maildir/" for qmail-style delivery (the / is required).
+#
+#home_mailbox = Mailbox
+#home_mailbox = Maildir/
+
+# The mail_spool_directory parameter specifies the directory where
+# UNIX-style mailboxes are kept. The default setting depends on the
+# system type.
+#
+#mail_spool_directory = /var/mail
+#mail_spool_directory = /var/spool/mail
+
+# The mailbox_command parameter specifies the optional external
+# command to use instead of mailbox delivery. The command is run as
+# the recipient with proper HOME, SHELL and LOGNAME environment settings.
+# Exception: delivery for root is done as $default_user.
+#
+# Other environment variables of interest: USER (recipient username),
+# EXTENSION (address extension), DOMAIN (domain part of address),
+# and LOCAL (the address localpart).
+#
+# Unlike other Postfix configuration parameters, the mailbox_command
+# parameter is not subjected to $parameter substitutions. This is to
+# make it easier to specify shell syntax (see example below).
+#
+# Avoid shell meta characters because they will force Postfix to run
+# an expensive shell process. Procmail alone is expensive enough.
+#
+# IF YOU USE THIS TO DELIVER MAIL SYSTEM-WIDE, YOU MUST SET UP AN
+# ALIAS THAT FORWARDS MAIL FOR ROOT TO A REAL USER.
+#
+#mailbox_command = /some/where/procmail
+#mailbox_command = /some/where/procmail -a "$EXTENSION"
+
+# The mailbox_transport specifies the optional transport in master.cf
+# to use after processing aliases and .forward files. This parameter
+# has precedence over the mailbox_command, fallback_transport and
+# luser_relay parameters.
+#
+# Specify a string of the form transport:nexthop, where transport is
+# the name of a mail delivery transport defined in master.cf. The
+# :nexthop part is optional. For more details see the sample transport
+# configuration file.
+#
+# NOTE: if you use this feature for accounts not in the UNIX password
+# file, then you must update the "local_recipient_maps" setting in
+# the main.cf file, otherwise the SMTP server will reject mail for
+# non-UNIX accounts with "User unknown in local recipient table".
+#
+#mailbox_transport = lmtp:unix:/var/lib/imap/socket/lmtp
+
+# If using the cyrus-imapd IMAP server deliver local mail to the IMAP
+# server using LMTP (Local Mail Transport Protocol), this is prefered
+# over the older cyrus deliver program by setting the
+# mailbox_transport as below:
+#
+# mailbox_transport = lmtp:unix:/var/lib/imap/socket/lmtp
+#
+# The efficiency of LMTP delivery for cyrus-imapd can be enhanced via
+# these settings.
+#
+# local_destination_recipient_limit = 300
+# local_destination_concurrency_limit = 5
+#
+# Of course you should adjust these settings as appropriate for the
+# capacity of the hardware you are using. The recipient limit setting
+# can be used to take advantage of the single instance message store
+# capability of Cyrus. The concurrency limit can be used to control
+# how many simultaneous LMTP sessions will be permitted to the Cyrus
+# message store.
+#
+# To use the old cyrus deliver program you have to set:
+#mailbox_transport = cyrus
+
+# The fallback_transport specifies the optional transport in master.cf
+# to use for recipients that are not found in the UNIX passwd database.
+# This parameter has precedence over the luser_relay parameter.
+#
+# Specify a string of the form transport:nexthop, where transport is
+# the name of a mail delivery transport defined in master.cf. The
+# :nexthop part is optional. For more details see the sample transport
+# configuration file.
+#
+# NOTE: if you use this feature for accounts not in the UNIX password
+# file, then you must update the "local_recipient_maps" setting in
+# the main.cf file, otherwise the SMTP server will reject mail for
+# non-UNIX accounts with "User unknown in local recipient table".
+#
+#fallback_transport = lmtp:unix:/var/lib/imap/socket/lmtp
+#fallback_transport =
+
+# The luser_relay parameter specifies an optional destination address
+# for unknown recipients. By default, mail for unknown@$mydestination,
+# unknown@[$inet_interfaces] or unknown@[$proxy_interfaces] is returned
+# as undeliverable.
+#
+# The following expansions are done on luser_relay: $user (recipient
+# username), $shell (recipient shell), $home (recipient home directory),
+# $recipient (full recipient address), $extension (recipient address
+# extension), $domain (recipient domain), $local (entire recipient
+# localpart), $recipient_delimiter. Specify ${name?value} or
+# ${name:value} to expand value only when $name does (does not) exist.
+#
+# luser_relay works only for the default Postfix local delivery agent.
+#
+# NOTE: if you use this feature for accounts not in the UNIX password
+# file, then you must specify "local_recipient_maps =" (i.e. empty) in
+# the main.cf file, otherwise the SMTP server will reject mail for
+# non-UNIX accounts with "User unknown in local recipient table".
+#
+#luser_relay = $user@other.host
+#luser_relay = $local@other.host
+#luser_relay = admin+$local
+
+# JUNK MAIL CONTROLS
+#
+# The controls listed here are only a very small subset. The file
+# SMTPD_ACCESS_README provides an overview.
+
+# The header_checks parameter specifies an optional table with patterns
+# that each logical message header is matched against, including
+# headers that span multiple physical lines.
+#
+# By default, these patterns also apply to MIME headers and to the
+# headers of attached messages. With older Postfix versions, MIME and
+# attached message headers were treated as body text.
+#
+# For details, see "man header_checks".
+#
+#header_checks = regexp:/etc/postfix/header_checks
+
+# FAST ETRN SERVICE
+#
+# Postfix maintains per-destination logfiles with information about
+# deferred mail, so that mail can be flushed quickly with the SMTP
+# "ETRN domain.tld" command, or by executing "sendmail -qRdomain.tld".
+# See the ETRN_README document for a detailed description.
+#
+# The fast_flush_domains parameter controls what destinations are
+# eligible for this service. By default, they are all domains that
+# this server is willing to relay mail to.
+#
+#fast_flush_domains = $relay_domains
+
+# SHOW SOFTWARE VERSION OR NOT
+#
+# The smtpd_banner parameter specifies the text that follows the 220
+# code in the SMTP server's greeting banner. Some people like to see
+# the mail version advertised. By default, Postfix shows no version.
+#
+# You MUST specify $myhostname at the start of the text. That is an
+# RFC requirement. Postfix itself does not care.
+#
+#smtpd_banner = $myhostname ESMTP $mail_name
+#smtpd_banner = $myhostname ESMTP $mail_name ($mail_version)
+
+# PARALLEL DELIVERY TO THE SAME DESTINATION
+#
+# How many parallel deliveries to the same user or domain? With local
+# delivery, it does not make sense to do massively parallel delivery
+# to the same user, because mailbox updates must happen sequentially,
+# and expensive pipelines in .forward files can cause disasters when
+# too many are run at the same time. With SMTP deliveries, 10
+# simultaneous connections to the same domain could be sufficient to
+# raise eyebrows.
+#
+# Each message delivery transport has its XXX_destination_concurrency_limit
+# parameter. The default is $default_destination_concurrency_limit for
+# most delivery transports. For the local delivery agent the default is 2.
+
+#local_destination_concurrency_limit = 2
+#default_destination_concurrency_limit = 20
+
+# DEBUGGING CONTROL
+#
+# The debug_peer_level parameter specifies the increment in verbose
+# logging level when an SMTP client or server host name or address
+# matches a pattern in the debug_peer_list parameter.
+#
+debug_peer_level = 2
+
+# The debug_peer_list parameter specifies an optional list of domain
+# or network patterns, /file/name patterns or type:name tables. When
+# an SMTP client or server host name or address matches a pattern,
+# increase the verbose logging level by the amount specified in the
+# debug_peer_level parameter.
+#
+#debug_peer_list = 127.0.0.1
+#debug_peer_list = some.domain
+
+# The debugger_command specifies the external command that is executed
+# when a Postfix daemon program is run with the -D option.
+#
+# Use "command .. & sleep 5" so that the debugger can attach before
+# the process marches on. If you use an X-based debugger, be sure to
+# set up your XAUTHORITY environment variable before starting Postfix.
+#
+debugger_command =
+ PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin
+ ddd $daemon_directory/$process_name $process_id & sleep 5
+
+# If you can't use X, use this to capture the call stack when a
+# daemon crashes. The result is in a file in the configuration
+# directory, and is named after the process name and the process ID.
+#
+# debugger_command =
+# PATH=/bin:/usr/bin:/usr/local/bin; export PATH; (echo cont;
+# echo where) | gdb $daemon_directory/$process_name $process_id 2>&1
+# >$config_directory/$process_name.$process_id.log & sleep 5
+#
+# Another possibility is to run gdb under a detached screen session.
+# To attach to the screen sesssion, su root and run "screen -r
+# <id_string>" where <id_string> uniquely matches one of the detached
+# sessions (from "screen -list").
+#
+# debugger_command =
+# PATH=/bin:/usr/bin:/sbin:/usr/sbin; export PATH; screen
+# -dmS $process_name gdb $daemon_directory/$process_name
+# $process_id & sleep 1
+
+# INSTALL-TIME CONFIGURATION INFORMATION
+#
+# The following parameters are used when installing a new Postfix version.
+#
+# sendmail_path: The full pathname of the Postfix sendmail command.
+# This is the Sendmail-compatible mail posting interface.
+#
+sendmail_path = /usr/sbin/sendmail.postfix
+
+# newaliases_path: The full pathname of the Postfix newaliases command.
+# This is the Sendmail-compatible command to build alias databases.
+#
+newaliases_path = /usr/bin/newaliases.postfix
+
+# mailq_path: The full pathname of the Postfix mailq command. This
+# is the Sendmail-compatible mail queue listing command.
+#
+mailq_path = /usr/bin/mailq.postfix
+
+# setgid_group: The group for mail submission and queue management
+# commands. This must be a group name with a numerical group ID that
+# is not shared with other accounts, not even with the Postfix account.
+#
+setgid_group = postdrop
+
+# html_directory: The location of the Postfix HTML documentation.
+#
+html_directory = no
+
+# manpage_directory: The location of the Postfix on-line manual pages.
+#
+manpage_directory = /usr/share/man
+
+# sample_directory: The location of the Postfix sample configuration files.
+# This parameter is obsolete as of Postfix 2.1.
+#
+sample_directory = /usr/share/doc/postfix-2.6.6/samples
+
+# readme_directory: The location of the Postfix README files.
+#
+readme_directory = /usr/share/doc/postfix-2.6.6/README_FILES
+
+smtpd_tls_cert_file=/etc/postfix/example.com.crt
+smtpd_tls_key_file=/etc/postfix/example.com.key
+protocols=!SSLv2, !SSLv3
+# protocols=!SSLv2, !SSLv3, !TLSv1, !TLSv1.1, TLSv1.2
+smtpd_tls_mandatory_protocols = $protocols
+smtp_tls_mandatory_protocols = $protocols
+smtpd_tls_protocols = $protocols
+smtp_tls_protocols = $protocols
+```
+
+Postfix のメインの設定ファイルです。
+長ったらしいですが、オリジナルから変更したのは以下の箇所のみです。
+
+```config
+smtpd_tls_cert_file=/etc/postfix/example.com.crt
+smtpd_tls_key_file=/etc/postfix/example.com.key
+protocols=!SSLv2, !SSLv3
+# protocols=!SSLv2, !SSLv3, !TLSv1, !TLSv1.1, TLSv1.2
+smtpd_tls_mandatory_protocols = $protocols
+smtp_tls_mandatory_protocols = $protocols
+smtpd_tls_protocols = $protocols
+smtp_tls_protocols = $protocols
+```
+SSL 証明書のパスと、プロトコル(初期設定では TLS 1 ~ 1.2, コメントを入れ替えれば、TLS 1.2 のみに変更可能)を設定しているだけです。
+
+```config:master.cf
+#
+# Postfix master process configuration file. For details on the format
+# of the file, see the master(5) manual page (command: "man 5 master").
+#
+# Do not forget to execute "postfix reload" after editing this file.
+#
+# ==========================================================================
+# service type private unpriv chroot wakeup maxproc command + args
+# (yes) (yes) (yes) (never) (100)
+# ==========================================================================
+smtp inet n - n - - smtpd
+#submission inet n - n - - smtpd
+# -o smtpd_tls_security_level=encrypt
+# -o smtpd_sasl_auth_enable=yes
+# -o smtpd_client_restrictions=permit_sasl_authenticated,reject
+# -o milter_macro_daemon_name=ORIGINATING
+smtps inet n - n - - smtpd
+ -o smtpd_tls_wrappermode=yes
+# -o smtpd_sasl_auth_enable=yes
+# -o smtpd_client_restrictions=permit_sasl_authenticated,reject
+# -o milter_macro_daemon_name=ORIGINATING
+#628 inet n - n - - qmqpd
+pickup fifo n - n 60 1 pickup
+cleanup unix n - n - 0 cleanup
+qmgr fifo n - n 300 1 qmgr
+#qmgr fifo n - n 300 1 oqmgr
+tlsmgr unix - - n 1000? 1 tlsmgr
+rewrite unix - - n - - trivial-rewrite
+bounce unix - - n - 0 bounce
+defer unix - - n - 0 bounce
+trace unix - - n - 0 bounce
+verify unix - - n - 1 verify
+flush unix n - n 1000? 0 flush
+proxymap unix - - n - - proxymap
+proxywrite unix - - n - 1 proxymap
+smtp unix - - n - - smtp
+# When relaying mail as backup MX, disable fallback_relay to avoid MX loops
+relay unix - - n - - smtp
+ -o smtp_fallback_relay=
+# -o smtp_helo_timeout=5 -o smtp_connect_timeout=5
+showq unix n - n - - showq
+error unix - - n - - error
+retry unix - - n - - error
+discard unix - - n - - discard
+local unix - n n - - local
+virtual unix - n n - - virtual
+lmtp unix - - n - - lmtp
+anvil unix - - n - 1 anvil
+scache unix - - n - 1 scache
+#
+# ====================================================================
+# Interfaces to non-Postfix software. Be sure to examine the manual
+# pages of the non-Postfix software to find out what options it wants.
+#
+# Many of the following services use the Postfix pipe(8) delivery
+# agent. See the pipe(8) man page for information about ${recipient}
+# and other message envelope options.
+# ====================================================================
+#
+# maildrop. See the Postfix MAILDROP_README file for details.
+# Also specify in main.cf: maildrop_destination_recipient_limit=1
+#
+#maildrop unix - n n - - pipe
+# flags=DRhu user=vmail argv=/usr/local/bin/maildrop -d ${recipient}
+#
+# ====================================================================
+#
+# The Cyrus deliver program has changed incompatibly, multiple times.
+#
+#old-cyrus unix - n n - - pipe
+# flags=R user=cyrus argv=/usr/lib/cyrus-imapd/deliver -e -m ${extension} ${user}
+#
+# ====================================================================
+#
+# Cyrus 2.1.5 (Amos Gouaux)
+# Also specify in main.cf: cyrus_destination_recipient_limit=1
+#
+#cyrus unix - n n - - pipe
+# user=cyrus argv=/usr/lib/cyrus-imapd/deliver -e -r ${sender} -m ${extension} ${user}
+#
+# ====================================================================
+#
+# See the Postfix UUCP_README file for configuration details.
+#
+#uucp unix - n n - - pipe
+# flags=Fqhu user=uucp argv=uux -r -n -z -a$sender - $nexthop!rmail ($recipient)
+#
+# ====================================================================
+#
+# Other external delivery methods.
+#
+#ifmail unix - n n - - pipe
+# flags=F user=ftn argv=/usr/lib/ifmail/ifmail -r $nexthop ($recipient)
+#
+#bsmtp unix - n n - - pipe
+# flags=Fq. user=bsmtp argv=/usr/local/sbin/bsmtp -f $sender $nexthop $recipient
+#
+#scalemail-backend unix - n n - 2 pipe
+# flags=R user=scalemail argv=/usr/lib/scalemail/bin/scalemail-store
+# ${nexthop} ${user} ${extension}
+#
+#mailman unix - n n - - pipe
+# flags=FR user=list argv=/usr/lib/mailman/bin/postfix-to-mailman.py
+# ${nexthop} ${user}
+```
+
+Postfix のメインの設定ファイルその 2 です。
+長ったらしいですが、オリジナルから変更したのは以下の箇所のみです。
+
+```config
+smtps inet n - n - - smtpd
+ -o smtpd_tls_wrappermode=yes
+```
+
+よくわかってないですが STARTTLS だとなんだか面倒くさそうだったので smtpd_tls_wrappermode を設定しています。
+
+# docker build
+docker build -t mypostfix .
+
+# docker run
+docker run -it mypostfix /run.sh mypostfix.example.com
+
+# postfix の起動/停止
+
+service postfix start
+service postfix stop
+service postfix restart
+
+/etc/init.d/postfix の中を見れば分かりますが、標準出力を全部 /dev/null に捨ています。
+そのため設定不備があった場合 service postfix start してもどこが悪いのかログが出ずに困ることになります。(/var/log/maillog とかも何も出ない)
+ログを見たい場合以下のようにします。
+
+/usr/sbin/postfix start
+/usr/sbin/postfix stop
+
+# TLS 1.2 の確認
+OpenSSL を使って確認します。
+
+```shell
+openssl s_client -connect mypostfix.example.com:465 -showcerts -tls1 # TLS 1.0
+openssl s_client -connect mypostfix.example.com:465 -showcerts -tls1_1 # TLS 1.1
+openssl s_client -connect mypostfix.example.com:465 -showcerts -tls1_2 # TLS 1.2
+```
+
+「New, (NONE), Cipher is (NONE)」と表示され、コマンドの入力待ちにならずに応答がすぐ返ってくる場合、接続できていません。
+証明書の情報が表示され、「220 mypostfix.example.com ESMTP Postfix」と表示され、コマンド入力待ちになった場合、接続できています。
+
+というわけで簡単にですが Postfix の Docker についての紹介でした。