Book Image

Hands-On Enterprise Automation with Python

By : Bassem Aly
Book Image

Hands-On Enterprise Automation with Python

By: Bassem Aly

Overview of this book

Hands-On Enterprise Automation with Python starts by covering the set up of a Python environment to perform automation tasks, as well as the modules, libraries, and tools you will be using. We’ll explore examples of network automation tasks using simple Python programs and Ansible. Next, we will walk you through automating administration tasks with Python Fabric, where you will learn to perform server configuration and administration, along with system administration tasks such as user management, database management, and process management. As you progress through this book, you’ll automate several testing services with Python scripts and perform automation tasks on virtual machines and cloud infrastructure with Python. In the concluding chapters, you will cover Python-based offensive security tools and learn how to automate your security tasks. By the end of this book, you will have mastered the skills of automating several system administration tasks with Python.
Table of Contents (20 chapters)

Reading stdin, stdout, and stderr

The spawned processes can communicate with the operating system in three channels:

  1. Standard input (stdin)
  2. Standard output (stdout)
  3. Standard error (stderr)

In subprocess, Popen() can interact with the three channels and redirect each stream to an external file, or to a special value called PIPE. An additional method, called communicate(), is used to read from the stdout and write on the stdin. The communicate() method can take input from the user and return both the standard output and the standard error, as shown in the following code snippet:

import subprocess
p = subprocess.Popen(["ping", "", "-c", "3"], stdin=subprocess.PIPE, stdout=subprocess.PIPE)
stdout, stderr = p.communicate()
print("""==========The Standard Output is==========