Ubuntu Server 22.04：如何将 Ansible debconf 值写入 Postfix 配置？

Question

我正在尝试将 Postfix 自动部署到多个 Ubuntu 服务器中：

# lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 22.04.3 LTS
Release:    22.04
Codename:   jammy

Ansible 任务具有预期的结果，但由于某种原因，值未写入 Postfix 配置。在此示例中，我将仅强调 的使用relayhost，预计它会写入/etc/postfix/main.cf：

任务：

- name: Install mail package
  ansible.builtin.apt:
    name: postfix
    autoremove: true
    update_cache: true
  environment:
    DEBIAN_FRONTEND: noninteractive

- name: Set mail configuration
  ansible.builtin.debconf:
    name: postfix
    question: postfix/{{ item.question }}
    value: '{{ item.value }}'
    vtype: '{{ item.vtype }}'
  notify: Restart mail service
  with_items:
    # General mail configuration type
    - question: main_mailer_type
      value: 'Satellite system'
      vtype: select
    # SMTP relay host
    - question: relayhost
      value: '[{{ cluster_mail_relay_host }}]:{{ cluster_mail_relay_port }}'
      vtype: string

- name: Flush handlers
  ansible.builtin.meta: flush_handlers

处理程序：

- name: Restart mail service
  ansible.builtin.systemd_service:
    name: postfix
    state: restarted
    enabled: true

正常的 Postfix 安装将在最后触发 Postfix 配置脚本，一旦完成，它将写入所有设置/etc/postfix/main.cf并重新加载服务。

因为我用 Ansible 来做这个，所以我用以下命令禁用交互模式：

  environment:
    DEBIAN_FRONTEND: noninteractive

接下来，我成功地写下了debconf问题。先前的 Ansible Postfix 安装：

# debconf-show postfix
#

Ansible 安装后：

# debconf-show postfix | egrep 'main_mailer_type|relayhost'
* postfix/relayhost: [smtp.mail.me.com]:587
* postfix/main_mailer_type: Satellite system

接下来，Ansible 处理程序会触发 Postfix 重启。但是，该relayhost值不会写入 Postfixmain.cf配置中，这是因为 Postfix 配置脚本正在触发内部命令，将配置设置写入 Postfixmain.cf并重新加载或重启服务。

配置不变，Ansible 任务执行后：

# grep relayhost /etc/postfix/main.cf
relayhost =

这就是我需要帮助的部分。查看脚本，我无法确定为什么写入/重新启动步骤没有以类似的行为使用 Ansible 执行。

Postfix 配置脚本：

# cat /var/lib/dpkg/info/postfix.config
#!/usr/bin/perl -w
# -*-CPerl-*-
# Script to configure Postfix.
# Based on code by Colin Walters <[email protected]>,
# and John Goerzen <[email protected]>.

use strict;
use warnings;

use Debconf::Client::ConfModule qw(:all);
use Fcntl;

my $version = version(2.0);
capb("backup");
title("Postfix Configuration");

# begin configuration script

my $topstate;
my $back;
my $noninteractive;
my $skiprelayhost;

# Regexps for checking domain names, blatantly stolen from exim config
my $rfc1035_label_re= '[0-9A-Za-z]([-0-9A-Za-z]*[0-9A-Za-z])?';
my $rfc1035_domain_re= "$rfc1035_label_re(\\.$rfc1035_label_re)*";
my $network_re= '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}/[0-9]{1,2}';

$topstate = "start";

my $distribution = lc(`lsb_release -is 2>/dev/null`);
$distribution = 'debian' if $distribution eq '';

while ($topstate ne "done") {
 TOPSTATE: {
    if ($topstate eq "start") {
      if (fget("postfix/main_mailer_type", "isdefault") eq "true") {
    if (-f "/etc/postfix/main.cf") {
        set("postfix/main_mailer_type", "No configuration");
    }
      }
      my $pri = "high";
      $pri = "medium" if ($ARGV[1] ne "" && $distribution eq "ubuntu");
      $noninteractive = (((input($pri, "postfix/main_mailer_type"))[0]) == 30);
      if ($noninteractive) {
    my $mailertype = get("postfix/main_mailer_type");
    if ($mailertype eq "No configuration") {
      # We can't display a note here, because it could send mail,
      # which isn't configured...
      #$noninteractive = ((input("critical", "postfix/not_configured"))[0] == 30);
      #go();
          fset("postfix/newaliases", "run", "false");
      $topstate="ending-setup";
    } else {
      $topstate="mailname";
    }
      } else {
    go();
    $back = (((go())[0]) == 30);
    my $mailertype = get("postfix/main_mailer_type");
    if ($mailertype eq "No configuration") {
      $topstate="ending-setup";
    } else {
      fset("postfix/main_mailer_type", "changed", "true");
          fset("postfix/newaliases", "run", "true");
      if ($back) {
        fset("postfix/main_mailer_type", "isdefault", "true");
      } else {
        fset("postfix/main_mailer_type", "changed", "true");
        $topstate = "mailname";
        if (!(($mailertype eq "Internet with smarthost") ||
          ($mailertype eq "Satellite system") ||
          ($mailertype eq "HP"))) {
          set("postfix/relayhost", "");
          fset("postfix/relayhost", "changed", "true");
        }
      }
    }
      }
    }

    if ($topstate eq "mailname") {
      my $mailname;
      if (-f "/etc/mailname") {
    if (open my $fh, '<', "/etc/mailname") {
      $mailname = <$fh>;
      close $fh;
      chomp $mailname;
    }
      }
      if (!defined($mailname) || $mailname eq "") {
    $mailname = `hostname --fqdn 2>/dev/null` || "localdomain";
    chomp $mailname;
      }
      # broken mailname, change it to the default, and prompt.
      if (lc($mailname) eq "ubuntu.com" || lc($mailname) eq "debian.org") {
    fset("postfix/mailname", "isdefault", "true");
    $mailname = `hostname --fqdn 2>/dev/null` || "localdomain";
    chomp $mailname;
      }
      if (fget("postfix/mailname", "isdefault") eq "true") {
    set("postfix/mailname", $mailname);
      }
      $noninteractive = (((input("high", "postfix/mailname"))[0]) == 30);
      if ($noninteractive) {
    $topstate = "relayhost";
      } else {
    $back = (((go())[0]) == 30);
    if ($back) {
      fset("postfix/main_mailer_type", "isdefault", "true");
      fset("postfix/mailname", "isdefault", "true");
      $topstate = "start";
    } else {
      # error checking
      my $mailname = lc(get("postfix/mailname"));
      fset("postfix/mailname", "changed", "true");
      if ($mailname eq "ubuntu.com" || $mailname eq "debian.org") {
        fset("postfix/mailname", "isdefault", "true");
      } elsif ($mailname =~ /$rfc1035_domain_re/ || $mailname eq "==default==") {
        # their mailname passed error checking, go on
        $topstate = "relayhost";
      } else {
        set("postfix/rfc1035_violation", "false");
        fset("postfix/rfc1035_violation", "isdefault", "true");
        subst("postfix/rfc1035_violation", "enteredstring", $mailname);
        $noninteractive = (((input("high", "postfix/rfc1035_violation"))[0]) == 30);
        $back = (((go())[0]) == 30);
        if ($back) {
          fset("postfix/mailname", "isdefault", "true");
          # and back around to ask mailname again.
        }
        if (get("postfix/rfc1035_violation") eq "true") {
          # they wanted to continue despite the error
          $topstate = "relayhost";
        } else {
          fset("postfix/mailname", "isdefault", "true");
          # and back around to ask mailname again.
        }
      }
    }
      }
    }

    if ($topstate eq "relayhost") {
      my $mailertype = get("postfix/main_mailer_type");
      if (($mailertype eq "Internet with smarthost") || ($mailertype eq "Satellite system")) {
    if (fget("postfix/relayhost", "isdefault") eq "true") {
      my $hostname = `hostname --domain 2>/dev/null` || "localdomain";
      chomp $hostname;
      my $relayname = "smtp." . $hostname;
      set("postfix/relayhost", $relayname);
    }
    $noninteractive = (((input("high", "postfix/relayhost"))[0]) == 30);
    $skiprelayhost=0;
      } else {
    # skip relayhost if we're an "Internet site" or a "Local only"
    $topstate = "root";
    $noninteractive=1;
    $skiprelayhost=1;
      }
      if ($noninteractive) {
    $topstate = "root";
      } else {
    $back = (((go())[0]) == 30);
    if ($back) {
      fset("postfix/mailname", "isdefault", "true");
      fset("postfix/relayhost", "isdefault", "true");
      $topstate = "mailname"; # we skip back to the last question of equal or higher priority
    } else {
      my $host = get("postfix/relayhost");
      if ($host =~ /[\s,]/) {
        fset("postfix/relayhost", "isdefault", "true");
      } else {
        fset("postfix/relayhost", "changed", "true");
        $topstate = "root";
      }
    }
      }
    }

    if ($topstate eq "root") {
      if (fget("postfix/root_address", "isdefault") eq "true") {
        my @l = ();
        if (open my $fh, '-|', "getent passwd 1000") {
          @l=<$fh>;
          close $fh;
        }
        if ($#l > 0) {
          $l[0] =~ s/:.*$//;
          set("postfix/root_address",$l[0]);
          fset("postfix/root_address", "changed", "true");
        }
      }
      $noninteractive = (((input("medium", "postfix/root_address"))[0]) == 30);
      if ($noninteractive) {
    $topstate="destinations";
      } else {
    $back = (((go())[0]) == 30);
    if ($back) {
      fset("postfix/relayhost", "isdefault", "true");
      fset("postfix/root_address", "isdefault", "true");
      if ($skiprelayhost) {
        fset("postfix/mailname", "isdefault", "true");
        $topstate = "mailname";
      } else {
        $topstate = "relayhost";
      }
    } else {
      fset("postfix/root_address", "changed", "true");
      $topstate="destinations";
    }
      }
    }

    if ($topstate eq "destinations") {
      my $mailertype = get("postfix/main_mailer_type");
      my $hostname = `hostname --fqdn 2>/dev/null` || "localhost";
      chomp $hostname;
      my $domain = `hostname --domain 2>/dev/null` || "localdomain";
      chomp $domain;
      my $mailname = get("postfix/mailname") || "localhost";
      my $destinations;
      my $priority="medium";
      if (fget("postfix/destinations", "set") eq "true") {
    if ((-x "/usr/sbin/postconf") && (-f "/etc/postfix/main.cf")) {
      if (open my $fh, '-|', "postconf -hx mydestination") {
        $destinations=<$fh>;
        close $fh;
        chomp $destinations;
        set("postfix/destinations", $destinations);
      }
    }
      } else {
    if ($mailertype eq "Internet Site") {
      if ($mailname eq $hostname) {
        $destinations = join ", ",("\$myhostname", $mailname, "localhost." . $domain, ", localhost");
      } else {
        $destinations = join ", ",("\$myhostname", $mailname, $hostname, "localhost." . $domain . ", localhost");
      }
    } else {
      # don't accept mail for $mailname by default if we have a relayhost or local only mail,
      # unless the mailname bears no resemblance to $myorigin.
      $destinations = join ", ",("\$myhostname", $hostname, "localhost." . $domain . ", localhost" );
      unless ( $hostname =~ m/(^|[\.])$mailname$/  ) {
        $destinations = $mailname . ", " . $destinations;
      }
    }
    set("postfix/destinations", $destinations);
    fset("postfix/destinations","set","true");
      }
      if ($mailertype eq "Local only") {
    $priority="low";
      }
      $noninteractive = (((input($priority, "postfix/destinations"))[0]) == 30);
      if ($noninteractive) {
    $topstate = "chattr";
      } else {
    $back = (((go())[0]) == 30);
    if ($back) {
      fset("postfix/relayhost", "isdefault", "true");
      fset("postfix/destinations", "isdefault", "true");
      $topstate = "relayhost";
    } else {
      fset("postfix/destinations", "changed", "true");
      $topstate = "chattr";
    }
      }
    }

    if ($topstate eq "chattr") {
      $noninteractive = (((input("medium", "postfix/chattr"))[0]) == 30);
      if ($noninteractive) {
    $topstate = "mynetworks";
      } else {
    $back = (((go())[0]) == 30);
    if ($back) {
      fset("postfix/destinations", "isdefault", "true");
      fset("postfix/chattr", "isdefault", "true");
      $topstate = "destinations";
    } else {
      fset("postfix/chattr", "changed", "true");
      $topstate = "mynetworks";
    }
      }
    }

    if ($topstate eq "mynetworks") {
      if ((-x "/usr/sbin/postconf") && (-f "/etc/postfix/main.cf")) {
    my $mynetworks;
    if (open my $fh, '-|', "postconf -hx mynetworks") {
      $mynetworks=<$fh>;
      close $fh;
      chomp $mynetworks;
      set("postfix/mynetworks", $mynetworks);
    }
      }
      $noninteractive = (((input("low", "postfix/mynetworks"))[0]) == 30);
      if ($noninteractive) {
    $topstate = "procmail";
      } else {
    $back = (((go())[0]) == 30);
    if ($back) {
      fset("postfix/chattr", "isdefault", "true");
      fset("postfix/mynetworks", "isdefault", "true");
      $topstate = "chattr";
    } else {
      fset("postfix/mynetworks", "changed", "true");
      $topstate = "procmail";
    }
      }
    }

    if ($topstate eq "procmail") {
      if (fget("postfix/procmail", "isdefault") eq "true") {
    my $pmdefault="false";
    if (-x "/usr/bin/procmail") {
      $pmdefault="true";
    }
    set("postfix/procmail", $pmdefault);
      }
      if (-x "/usr/bin/procmail") {
    $noninteractive = (((input("low", "postfix/procmail"))[0]) == 30);
      } else {
    $noninteractive = 1;
      }
      if ($noninteractive) {
    $topstate = "mailbox_limit";
      } else {
    $back = (((go())[0]) == 30);
    if ($back) {
      fset("postfix/mynetworks", "isdefault", "true");
      fset("postfix/procmail", "isdefault", "true");
      $topstate = "mynetworks";
    } else {
      fset("postfix/procmail", "changed", "true");
      $topstate = "mailbox_limit";
    }
      }
    }

    if ($topstate eq "mailbox_limit") {
      $noninteractive = (((input("low", "postfix/mailbox_limit"))[0]) == 30);
      if ($noninteractive) {
    $topstate = "recipient_delim";
      } else {
    $back = (((go())[0]) == 30);
    if ($back) {
      fset("postfix/procmail", "isdefault", "true");
      fset("postfix/mailbox_limit", "isdefault", "true");
      if (-x "/usr/bin/procmail") {
        $topstate = "procmail";
      } else {
        fset("postfix/mynetworks", "isdefault", "true");
        $topstate = "mynetworks";
      }
    } else {
      fset("postfix/mailbox_limit", "changed", "true");
      $topstate = "recipient_delim";
    }
      }
    }

    if ($topstate eq "recipient_delim") {
      $noninteractive = (((input("low", "postfix/recipient_delim"))[0]) == 30);
      if ($noninteractive) {
    $topstate = "protocols";
      } else {
    $back = (((go())[0]) == 30);
    if ($back) {
      fset("postfix/mailbox_limit", "isdefault", "true");
      fset("postfix/recipient_delim", "isdefault", "true");
      $topstate = "mailbox_limit";
    } else {
      my $delim = get("postfix/recipient_delim");
      if (length($delim) > 1) {
        fset("postfix/bad_recipient_delimiter","isdefault","true");
        subst("postfix/bad_recipient_delimiter", "enteredstring", $delim);
        $noninteractive = (((input("low", "postfix/bad_recipient_delimiter"))[0]) == 30);
        fset("postfix/recipient_delim","isdefault","true");
        # and do it again...
      } else {
        fset("postfix/recipient_delim", "changed", "true");
        $topstate = "protocols";
      }
    }
      }
    }

    if ($topstate eq "protocols") {
      if ((-x "/usr/sbin/postconf") && (-f "/etc/postfix/main.cf")) {
    my $protos;
    if (open my $fh, '-|', "postconf -hx inet_protocols") {
      $protos=<$fh>;
      close $fh;
      chomp $protos;
      set("postfix/protocols", $protos);
    }
      } elsif (fget("postfix/protocols", "isdefault") eq "true") {
    my $protos;
    if (-d "/proc/sys/net/ipv6" && -d "/proc/sys/net/ipv4") {
      $protos="all";
    } elsif (-d "/proc/sys/net/ipv6") {
      $protos="ipv6";
    } elsif (-d "/proc/sys/net/ipv4") {
      $protos="ipv4";
    }
    set("postfix/protocols", $protos) if $protos;
      }

      $noninteractive = (((input("low", "postfix/protocols"))[0]) == 30);
      if ($noninteractive) {
    $topstate = "ending-setup";
      } else {
    $back = (((go())[0]) == 30);
    if ($back) {
      fset("postfix/recipient_delim", "isdefault", "true");
      fset("postfix/protocols", "isdefault", "true");
      $topstate = "recipient_delim";
    } else {
      fset("postfix/protocols", "changed", "true");
      $topstate = "ending-setup";
    }
      }
    }

    if ($topstate eq "ending-setup") {
      if ($ARGV[0] eq "reconfigure") {
    # touch /var/lib/postfix/reload
    if (sysopen my $fh, "/var/spool/postfix/reload", O_CREAT) {
      close $fh;
    }
      } else {
    # touch /var/lib/postfix/restart
    if (sysopen my $fh, "/var/spool/postfix/restart", O_CREAT) {
      close $fh;
    }
      }
      $topstate = "done";
    }
  }             # end TOPSTATE
}               # end while ($topstate ne q(done))

在脚本的底部，有一个创建空文件的条件：

    if ($topstate eq "ending-setup") {
      if ($ARGV[0] eq "reconfigure") {
    # touch /var/lib/postfix/reload
    if (sysopen my $fh, "/var/spool/postfix/reload", O_CREAT) {
      close $fh;
    }
      } else {
    # touch /var/lib/postfix/restart
    if (sysopen my $fh, "/var/spool/postfix/restart", O_CREAT) {
      close $fh;
    }
      }
      $topstate = "done";
    }

在调用 Ansible 处理程序之前，我尝试接触该文件，但什么也没有发生。

- name: Create spool file
  ansible.builtin.file:
    path: /var/spool/postfix/restart
    state: touch
    owner: root
    group: root
    mode: '0644'

- name: Flush handlers
  ansible.builtin.meta: flush_handlers

但没有结果，debconf设置没有写入main.cf文件中。

我知道我可以用以下方式编写设置：

- name: Update mail configuration
  ansible.builtin.command:
    cmd: postconf -e 'relayhost = [{{ cluster_mail_relay_host }}]:{{ cluster_mail_relay_port }}'
  changed_when: true

但我的目标是了解debconf相关过程。

感谢您的帮助。

Answer 1

更改执行顺序可以解决问题，我猜在安装时，Postfix 会检查是否有任何预定义debconf设置并应用它们：

- name: Set mail configuration
  ansible.builtin.debconf:
    name: postfix
    question: postfix/{{ item.question }}
    value: '{{ item.value }}'
    vtype: '{{ item.vtype }}'
  notify: Restart mail service
  with_items:
    # General mail configuration type
    - question: main_mailer_type
      value: 'Satellite system'
      vtype: select
    # SMTP relay host
    - question: relayhost
      value: '[{{ cluster_mail_relay_host }}]:{{ cluster_mail_relay_port }}'
      vtype: string

- name: Install mail package
  ansible.builtin.apt:
    name: postfix
    autoremove: true
    update_cache: true
  environment:
    DEBIAN_FRONTEND: noninteractive