iptables and combining additional rule sources

[Jeffrey Walton]

On Fri, Apr 24, 2020 at 11:07 PM Valdis Klētnieks
<valdis.kletnieks at vt.edu> wrote:
>
> On Fri, 24 Apr 2020 18:28:21 -0400, Jeffrey Walton said:
>
> > The problem I am having is, adding the new information to the existing
> > iptables rules in /etc/sysconfig/iptables. I want to write my rules to
> > a separate file and then tell /etc/sysconfig/iptables to include it at
> > the correct position.
> >
> > I read the iptables(8), iptables-save(8) and iptables-restore(8) man
> > pages, but I don't see how to combine the different sources.
> >
> > How do I tell iptables to include a second external source at a
> > specific location?
>
> Turn the problem on its side....
>
> #!/bin/bash
> cat /etc/iptables.header /etc/iptables.newstuff /etc/iptables.trailer > /etc/sysconfig/iptables
> iptables-restore < /etc/sysconfig/iptables
>
> (basically the solution I did for an NFS server, where 'newstuff' and /etc/exports were
> both machine-generated by a perl script that read a config file of authorized clients.

That's a good idea. I think that may work better for some data sets.

One last question... Should I create my own target - say mediawiki -
and append my rules to it? That may simplify things:

* Header, newstuff and trailer is fixed
* newstuff just jumps to mediawiki target
* if mediawiki does not ban, then control returns to trailer

Then, my out-of-proc service just keeps adding to mediawiki target. I
don't need to write files in this case. I'll just keep adding to the
running config.

Jeff