[Docs] Advanced networking documentation

[riccardotornesello]

Description

This PR aims to add documentation concerning advanced concepts of the liqo's network fabric.

Contributors

• @cheina97
• @MircoBarone
• @riccardotornesello
• @Gabbe64

Updates

Documentation

The main contribution concerns the addition of a section on Liqo's architecture, specifically its network architecture.

The following pages have been added to Architecture / Liqo's network:

• Basic Concepts
• Pod-to-Pod Example
• Leaf-to-Leaf Communication
• NodePort
• Firewall Configuration
• Route Configuration
• IP
• InternalNode

Sphinx

The Sphinx installation system has been changed: currently, the packages needed to compile the documentation are installed without a Python virtual environment, but this is no longer supported by default in new versions of PIP, so it has been necessary to use virtual environments in the Makefile.

Furthermore, to make local execution lighter and simpler, Nginx (via Docker) has been replaced with the native Python “http” module, which allows a static http server to be exposed.

Finally, the README has been modified to suggest that users use the autoserve command, which is more useful during development than serve thanks to its autoreload feature.

[adamjensenbot]

Hi @riccardotornesello. Thanks for your PR!

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Make sure this PR appears in the liqo changelog, adding one of the following labels:

• feat: 🚀 New Feature
• fix: 🐛 Bug Fix
• refactor: 🧹 Code Refactoring
• docs: 📝 Documentation
• style: 💄 Code Style
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• test: ✅ Tests
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[frisso]

Suggested change

	The role of the gateway, either _client_ or _server_, can be dynamically configured before starting the peering.
	In other words, this role does not depend whether the cluster is a Liqo resource _provider_ or _consumer_, although the default choice is to have the cluster provider acting as a gateway server, and the consumer acting as gateway client.