The Little Relay that Could¶
Let's say you just set up your very first Tor relay (thank you!), and now you want to write a script that tells you how much it is being used.
First, for any script to talk with your relay it will need to have a control port available. This is a port that's usually only available on localhost and protected by either a password or authentication cookie.
Look at your torrc for the following configuration options...
# This provides a port for our script to talk with. If you set this then be # sure to also set either CookieAuthentication *or* HashedControlPassword! # # You could also use ControlSocket instead of ControlPort, which provides a # file based socket. You don't need to have authentication if you use # ControlSocket. For this example however we'll use a port. ControlPort 9051 # Setting this will make Tor write an authentication cookie. Anything with # permission to read this file can connect to Tor. If you're going to run # your script with the same user or permission group as Tor then this is the # easiest method of authentication to use. CookieAuthentication 1 # Alternatively we can authenticate with a password. To set a password first # get its hash... # # % tor --hash-password "my_password" # 16:E600ADC1B52C80BB6022A0E999A7734571A451EB6AE50FED489B72E3DF # # ... and use that for the HashedControlPassword in your torrc. HashedControlPassword 16:E600ADC1B52C80BB6022A0E999A7734571A451EB6AE50FED489B72E3DF
When you change your torrc you'll need to either restart Tor or issue a SIGHUP for the new settings to take effect. Now let's write a script that tells us how many bytes Tor has sent and received since it started. Note that there are a few ways to connect to Tor. If you're unfamiliar with the 'with' keyword then see here...
from stem.control import Controller with Controller.from_port(port = 9051) as controller: controller.authenticate() # provide the password here if you set one bytes_read = controller.get_info("traffic/read") bytes_written = controller.get_info("traffic/written") print("My Tor relay has read %s bytes and written %s." % (bytes_read, bytes_written))
% python example.py My Tor relay has read 33406 bytes and written 29649.
Congratulations! You've just written your first controller script.