Jim Garrison:
> For anyone encountering this error, I've traced it to a regression of
> a very old bug relating to systemd service ordering dependencies.
>
> In my case, OS is CentOS Linux release 8.4.2105
> postfix-3.5.8-1.el8.x86_64
>
> Since a recent update I've found that, after every reboot, Postfix fails
> to start, and logs the message
>
> fatal: parameter inet_interfaces: no local interface found for 127.0.0.2
>
> If I then manually start Postfix (systemctl start postfix) it starts
> right up with no complaints.
>
> Long story short, this appears to be a regression of the 6-year-old
> systemd problem documented at
>
> https://bugs.launchpad.net/ubuntu/+source/postfix/+bug/1519331
>
> The problem is that in CentOS 8, a recent update seems to have changed
> Postfix's systemd service dependency from
>
> After=syslog.target network-online.target
>
> to
>
> After=syslog.target network.target
>
> This means that Postfix now starts up before the network is completely
> up, and systemd's DNS resolution hack (systemd-resolved.service),
> finding no interfaces up yet, resolves 'localhost' to 127.0.0.2.
>
> (man systemd-resolved.service)
>
> The simple fix is to create an override file with
>
> systemctl edit postfix.service"
>
> and restore the "After=" dependency on network-online.target
Thanks. I agree, Postfix should start up after the network is fully
initialized. That includes all the network interfaces, and all the
network infrastructure services.
Wietse
