To view INPUT, FORWARD, OUTPUT iptables rules just use: iptables -Siptables -S Here is an example output: -P INPUT ACCEPT -P FORWARD ACCEPT -P OUTPUT ACCEPT -A INPUT -i tun0 -j ACCEPT -A INPUT -i ens2 -p udp -m udp –dport 1194 -j ACCEPT -A FORWARD -i tun0 -o ens2 -j ACCEPT -A FORWARD -i […]

Use this iptables command-line to view all NAT rules: iptables -t nat -Siptables -t nat -S Here is an example output: -P PREROUTING ACCEPT -P INPUT ACCEPT -P POSTROUTING ACCEPT -P OUTPUT ACCEPT -A POSTROUTING -s 10.8.0.0/24 -o ens2 -j MASQUERADE-P PREROUTING ACCEPT -P INPUT ACCEPT -P POSTROUTING ACCEPT -P OUTPUT ACCEPT -A POSTROUTING -s […]

Need to parse command-line arguments in a bash script? Personally I always use this method: #!/bin/bash   while [[ "$#" -gt 0 ]]; do case $1 in -d|–deploy) deploy="$2"; shift ;; -u|–uglify) uglify=1 ;; *) echo "Unknown parameter passed: $1"; exit 1 ;; esac shift done   echo "Should deploy? $deploy" echo "Should uglify? $uglify"#!/bin/bash […]

There is Debian package named “iptables-persistent”. iptables-persistent makes sure iptables rules survive a reboot. To install it just type this command: apt-get -y install iptables-persistentapt-get -y install iptables-persistent To install it in an automated way check this: Bash Install Iptables-Persistent Automatically Other useful info can be found here: https://wiki.debian.org/iptables

Check if iptables-persistent is installed, else install it: if [[ $(dpkg -s iptables-persistent) != *"Status: install ok installed"* ]]; then echo iptables-persistent iptables-persistent/autosave_v4 boolean true | sudo debconf-set-selections echo iptables-persistent iptables-persistent/autosave_v6 boolean true | sudo debconf-set-selections apt-get -y install iptables-persistent fiif [[ $(dpkg -s iptables-persistent) != *"Status: install ok installed"* ]]; then echo iptables-persistent iptables-persistent/autosave_v4 […]