firehol ubuntu 20.04 ERROR: Neither IPv4 nor IPv6 is available - exiting

[Pieter]

$ sudo firehol
 WARNING: error initializing iptables: IPv4 disabled
 WARNING: error initializing ip6tables: IPv6 disabled
 ERROR: Neither IPv4 nor IPv6 is available - exiting

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 20.04.1 LTS
Release: 20.04
Codename: focal

$ sudo iptables -L -t filter | wc
     81 384 4513

$ apt-cache policy firehol
firehol:
  Installed: 3.1.5+ds-1ubuntu1
  Candidate: 3.1.5+ds-1ubuntu1
  Version table:
 *** 3.1.5+ds-1ubuntu1 500
        500 http://nz.archive.ubuntu.com/ubuntu focal/universe amd64 Packages
        500 http://nz.archive.ubuntu.com/ubuntu focal/universe i386 Packages
        100 /var/lib/dpkg/status

[Dominik Stadler (dominik-stadler)]

See also discussion at https://github.com/firehol/firehol/issues/264

[Michael Ehrenreich (mickdermack)]

This seems unrelated to https://github.com/firehol/firehol/issues/264

The paths to iptables et al. in /usr/lib/firehol/install.config are wrong. They should be /usr/sbin/ip{,6}tables{,-save,-restore}, but they are /sbin/ip{,6}tables{,-save,-restore}.

After fixing the paths locally, it seems to work.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[hami (zr-zz-alp)]

Edit 2022-03-14:
It is possible that I added the command environment variables as per instruction by https://github.com/firehol/firehol/issues/431
So, please consider using Michael's workaround for the time being.

=========

I previously have firehol installed on a 20.04 (server A), and it runs just fine (have encountered #264 of course).
Yesterday, I tried to install firehol on another 20.04 (server B), and encountered error:

user@B:~$ sudo firehol try
 WARNING: error initializing iptables: IPv4 disabled
 WARNING: error initializing ip6tables: IPv6 disabled
 ERROR: Neither IPv4 nor IPv6 is available - exiting

Both server A and B user install.config:
$ grep iptables /usr/lib/firehol/install.config
IPTABLES_CMD="/sbin/iptables"
IPTABLES_RESTORE_CMD="/sbin/iptables-restore"
IPTABLES_SAVE_CMD="/sbin/iptables-save"

I I found out the difference is that on server A, there is a default config file:
root@A:~# grep iptables /etc/firehol/firehol-defaults.conf | grep -v \#
IPTABLES_CMD="/usr/sbin/iptables"
IPTABLES_SAVE_CMD="/usr/sbin/iptables-save"
IPTABLES_RESTORE_CMD="/usr/sbin/iptables-restore"

So, the correct command is listed in firehol-defaults.conf

I tried to list the file dates:

root@A:~# ls -lah /usr/lib/firehol/
drwxr-xr-x 2 root root 4.0K Oct 10 2019 .
drwxr-xr-x 96 root root 12K Mar 9 03:06 ..
-rwxr-xr-x 1 root root 357K Jun 22 2020 firehol
-rwxr-xr-x 1 root root 102K Nov 4 2017 fireqos
-rw-r--r-- 1 root root 2.1K Nov 4 2017 functions.common
-rw-r--r-- 1 root root 2.3K Nov 4 2017 install.config

root@A:~# ls -lah /etc/firehol
drwxr-xr-x 4 root root 4.0K Oct 13 2019 .
drwxr-xr-x 181 root root 12K Mar 10 03:21 ..
-rw-r--r-- 1 root root 2.0K Mar 8 04:26 firehol.conf
-rw-r--r-- 1 root root 22K Jun 22 2020 firehol-defaults.conf
-rw-r--r-- 1 root root 190 Sep 20 2017 fireqos.conf

While I cannot be sure whether I touched the file or not, it seems highly likely to me that the firehol-defaults.conf could come from a installation back in the 2020. Maybe somehow the file got lost in the packaging process? Or maybe I installed firehol through source? I really don't know

It is suggested by firehol website that firehol-defaults.conf should better be included:
https://firehol.org/firehol-manual/firehol-defaults-conf/
Quote "
From FireHOL 3 upwards, variables which control FireHOL behaviour are held in a separate file: /etc/firehol/firehol-defaults.conf.

Some variables can also be set in the main firehol.conf file but that is not recommended, since they may be used before the main configuration is processed.

FireHOL also sets some variables before processing the configuration file which you can use as part of your configuration. These are described in firehol.conf(5).
"

Just my two cents.