Boring Shepherd

The shepherd's (pasteur) power manifests itself, therefore, in a duty, a task to be undertaken, so that - and I think this is also an important characteristic of pastoral power - the form it takes is not first of all the striking display of strength and superiority. Pastoral power initially manifests itself in its zeal, devotion, and endless application. What is the shepherd (berger)? Is (s)he someone whose strength strikes people's eyes, like the sovereigns or gods, like the Greek gods, who essentially appear in their splendor? Not at all. The shepherd is someone who keeps watch. (S)he "keeps watch" in the sense, of course, of keeping an eye out for possible evils, but above all in the sense of vigilance with regard to any possible misfortune.

• Michel Foucault, Security, Territory, Population: Lectures at the Collége de France (1977-1978)

The mind machine shepherd.

The Shepherd class spins up the flock of Sheep and lets them roam free.

The BoringShepherd class leaves the details of creating Sheep to the user, but still defines some useful methods.

The constructor calls a method to setup the flock. The method to setup the flock loops over each key.

For each key, it:

• validates the key
• creates a Sheep from the key

There are also two methods to perform actions with the flock: one for serial and one for parallel.

Constructor

This defines a generic Shepherd constructor that takes the following parameters:

• json_keys_dir: Directory where Sheep API keys are located
• flock_name: The name of the bot flock (used to format log messages)
• sheep_class: Type of Sheep
• **kwargs: Logging parameters passed directly to Lumberjack logger

Example:

Suppose we have the following directory structure:

$ ls keys/
bot_key1.json
bot_key2.json
bot_key3.json

Constructor Call Order

The call order for the constructor is as follows:

• Shepherd contructor calls create_flock() method
• create_flock() method loads each key in a directory and calls two methods:
  • Private method _validate_key() is called to check the bot key
  • Private method _create_sheep() is called to create the Sheep

To extend the BoringShepherd class, you must extend both the _create_sheep() and _validate_key() classes (they are undefined/virtual methods in the base class).

Example:

Suppose we have the following directory structure:

$ ls keys/
bot_key1.json
bot_key2.json
bot_key3.json

Now we create a custom Shepherd class that extends the _create_sheep() and _validate_key() methods, and use the custom Shepherd class to

(We illustrate performing basic key validation by checking for keys with a particular name.)

import boringmindmachine as bmm

class BlueShepherd(bmm.BoringShepherd):

    def _validate_key(self, bot_key, **kwargs):
        """
        Validate a bot key, passed in as a dictionary.
        Sole purpose of this function: raise an exception if there is a problem.
        """
        required_keys = ['key1','key2','key3']
        for key in required_keys:
            if key not in bot_key.keys():
                err = "ERROR: the bot key is missing a required key '%s'."%(key)
                raise Exception(err)

    def _create_sheep(self):
        sheep = self.sheep_class(bot_key)
        self.flock.append(sheep)

Performing Actions

The Shepherd and Sheep use the dispatcher pattern to call methods. The dispatcher pattern is used to turn a string (like "tweet") into a function call (like tweet()).

import boringmindmachine as bmm
import time

class FlatulentSheep(bmm.BoringSheep):
    def pass_gas(self):
        print("pfffft")
        time.sleep(30)

if __name__=="__name__":
    s = bmm.BoringShepherd(
                keys_dir = "keys/",
                flock_name = "flatulent_flock",
                sheep_class = FlatulentSheep
    )
    s.perform_parallel_action('pass_gas')

Adding Parameters to Actions

If we wanted to add a parameter with a default value (for example, the string being printed by pass_gas()), we can use **kwargs as follows;

import boringmindmachine as bmm
import time

class FlatulentSheep(bmm.BoringSheep):
    def pass_gas(self,, **kwargs):
        if 'message' in kwargs:
            msg = kwargs['message']
        else:
            msg = 'pfffffft'
        print(msg)
        time.sleep(30)

if __name__=="__name__":
    s = bmm.BoringShepherd(
                keys_dir = "keys/",
                flock_name = "flatulent_flock",
                sheep_class = FlatulentSheep
    )
    s.perform_parallel_action(
            'pass_gas',
            message = 'FFFRRRRRRRRRAAAAAAAPPPPPPP'
    )