execute shell script in ruby - ruby

Question

I want to execute the following shell script
system('echo "
rdr pass on lo0 inet proto tcp from any to 192.168.99.1 port 80 -> 192.168.99.1 port 8080
rdr pass on lo0 inet proto tcp from any to 192.168.99.1 port 443 -> 192.168.99.1 port 4443
" | sudo pfctl -ef - > /dev/null 2>&1; echo "==> Fowarding Ports: 80 -> 8080, 443 -> 4443 & Enabling pf"'
)
This works fine, i now want to pass the IP address loaded from a YAML file, i tried the following
config.yaml
configs:
use: 'home'
office:
public_ip: '192.168.99.2'
home:
public_ip: '192.168.99.1'
Vagrantfile
require 'yaml'
current_dir = File.dirname(File.expand_path(__FILE__))
configs = YAML.load_file("#{current_dir}/config.yaml")
vagrant_config = configs['configs'][configs['configs']['use']]
system('echo "
rdr pass on lo0 inet proto tcp from any to '+vagrant_config['public_ip']+' port 80 -> '+vagrant_config['public_ip']+' port 8080
rdr pass on lo0 inet proto tcp from any to '+vagrant_config['public_ip']+' port 443 -> '+vagrant_config['public_ip']+' port 4443
" | sudo pfctl -ef - > /dev/null 2>&1; echo "==> Fowarding Ports: 80 -> 8080, 443 -> 4443 & Enabling pf"'
)
The second method does not work, nor it shows any error, can someone point me to the right direction, what i want is to read public_ip dynamically from config file or variable
Thanks
UPDATE 1
I get the following output
pfctl: Use of -f option, could result in flushing of rules
present in the main ruleset added by the system at startup.
See /etc/pf.conf for further details.
No ALTQ support in kernel
ALTQ related functions disabled
pfctl: pf already enabled
What can be possibly wrong?

Answer 1

For troubleshooting purposes, it would be wise to output the command you're going to run prior to sending it out to system.
cmd = 'echo "
rdr pass on lo0 inet proto tcp from any to '+vagrant_config['public_ip']+' port 80 -> '+vagrant_config['public_ip']+' port 8080
rdr pass on lo0 inet proto tcp from any to '+vagrant_config['public_ip']+' port 443 -> '+vagrant_config['public_ip']+' port 4443
" | sudo pfctl -ef - > /dev/null 2>&1; echo "==> Fowarding Ports: 80 -> 8080, 443 -> 4443 & Enabling pf"'
puts "Command to run:\n\n#{cmd}"
system( cmd )
Then, it would be wise to make the output from the system command visible. To make sure you get this feedback, I suggest you replace
sudo pfctl -ef - > /dev/null 2>&1
with (adding '-v' for more verbose output - pfctl man page)
sudo pfctl -efv -
and then look for the output and/or error messages.
Then, once the bugs are sorted out, you can put it back into stealthy, quiet mode :D
Also, since you are running with sudo you'll need to make sure the shell you're running within has sudo privileges and also make sure you're not being prompted for a password unknowingly.