Phase 1: Linux Bash and Networking

Author: GPS

How does this phase apply to Cloud?

The cloud is essentially a collection of networked Linux servers. Understanding networking fundamentals and how to interact with these servers via commands and automate those commands with scripts is crucial. If you're already a Linux admin or network engineer, you can apply your skills to the cloud directly.

Prerequisites

• Create a GitHub account: Along side learning to script and later on to to code (though scripting is code), you'll need leverage Git, the most popular version control tool and a core DevOps practice. Git is used to manage and share your code, and GitHub is a leading repository hosting service.

How to break down this phase

Order	Topic
1	Introduction to Bash
2	Introduction to Networking

Resources

Topic	Title	Notes	Tips
Bash	Linux Basics for Hackers	This book made learning Linux FUN! It's pretty easy to follow and take a chapter day by day.	You don't need to read the whole thing, the first 9 chapters cover most of what you need to know.
Bash for Beginners	YouTube Video Series	An introduction to Bash!	A 20 part YouTube series covering the fundamentals of Bash.
Networking	Computer Networking Course - Network Engineering	You'll learn the fundamental principles of computer networking to prepare you for cloud.

Capstone Project: CloudUploader CLI

Create a bash-based CLI tool that allows users to quickly upload files to a specified cloud storage solution, providing a seamless upload experience similar to popular storage services.

Your tool should be able to upload a file:

clouduploader /path/to/file.txt

Steps:

1. Create a GitHub Repo:

   • Set up a repository for your project.
   • Use branches and commit your code often.
   • Utilize git commands (git init, git add, git commit, git branch, git push, etc.).

2. Setup & Authentication:

   • Choose a cloud provider (e.g., AWS S3, Google Cloud Storage, Azure Blob Storage).
   • Set up authentication (e.g., az login for Azure).
   • Use secure methods for handling credentials.
     • Avoid hardcoding credentials directly into the script.
     • Store credentials in environment variables or configuration files with restricted access.
     • Utilize cloud provider's secure authentication methods (e.g., IAM roles for AWS, service principals for Azure).

3. CLI Argument Parsing:

   • Use bash's built-in $1, $2, etc., to parse command-line arguments.
   • $1 could be the filename or path.
   • Optionally, allow additional arguments like target cloud directory, storage class, or any other cloud-specific attributes.
   • Validate and handle different types of input.\
     • Check if the provided file path is valid and accessible.
     • Ensure that additional arguments meet expected formats and values.
     • Provide meaningful error messages for incorrect or missing inputs

4. File Check:

   • Before uploading, check if the file exists using [ -f $FILENAME ].
   • Provide feedback if the file is not found.

5. File Upload:

   • Use the cloud provider's CLI to upload the file.
   • Implement error handling to manage potential issues during upload.

6. Upload Feedback:

   • On successful upload, provide a success message.
   • If there's an error, capture the error message and display it to the user.

7. Advanced Features (Optional but recommended):

   • Add a progress bar or percentage upload completion using tools like pv.
   • Provide an option to generate and display a shareable link post-upload.
   • Enable file synchronization -- if the file already exists in the cloud, prompt the user to overwrite, skip, or rename.
   • Integrate encryption for added security before the upload.

8. Documentation:

   • Write a README.md file explaining how to set up, use, and troubleshoot the tool.
   • Include a brief overview, prerequisites, usage examples, and common issues.

9. Distribution:

   • Package the script for easy distribution and installation. You can even provide a simple installation script or instructions to add it to the user's $PATH.

Things you should be able familiar with at the end of this phase

Commands

• Navigate with the cd command.
• How to list the contents of a directory and using the ls command.
• Create, copy, move, rename, directories and files with mkdir, cp, rm, and touch commands.
• Find things with locate, whereis, which, and find commands.
• Understand how to learn more about commands with the which, man, and --help commands.
• Familiar with finding logs details in /var/log
• How to display the contents of a file with cat, less, more, tail, head.
• Filtering with grep and sed.
• Redirection of standard input, output and error with > operator and tee command.
• How to use pipelines with the | operator.
• Manipulate files with nano or vim.
• Install and uninstall packages. Depends on distro, debian based use apt.
• Control permissions with chown, chgrp, chmod commands.
• Creating users and the sudo command.
• Process management with ps, top, nice, kill
• Manage environment aud user defined variables with env, set, export commands.
• Add directories to your PATH.
• Compression and archiving with tar, gzip, gunzip.
• How to access a Linux server with ssh.

Networking

Concepts you should be familiar with.

• OSI Model
• IP Addresses
• MAC Addresses
• Routing and Switching
• TCP/IP
• TCP and UDP
• DNS
• VPN tunneling
• TLS and SSL

Bash Scripting

• What is a shell?
• What is Bash?
• Why does a script have to start with #!?
• What is a variable and how to use them
• How to accept user input
• How to execute a script

Certifications you might want to look into

These certifications provide a comprehensive foundation but are not mandatory for entry-level cloud roles.

Linux

• LPI
• RedHat
• Linux Foundation
• Comptia Linux+

Networking

• Cisco certifications
• Comptia Network+