gont

Gont - A Go network testing toolkit

Gont is a package to create realistic virtual network, running real kernel, switch and application code, on a single machine (VM, cloud or native).

Gont is heavily inspired by Mininet. It allows the user to build virtual network topologies using Go code. Under the hood the network is then constructed using Linux virtual bridges and network namespaces.

Getting started

Have a look at our slide set to get you started.

Features

• Various common network nodes:

  • Standard host
  • Layer-3 Routers
  • Layer-2 Switches
  • Layer-3 NAT Routers
  • Layer-3 NAT to host networks

• Hostname resolution for test nodes (/etc/hosts overlay)

• Execution of sub-processes, Go code & functions in the network namespace of test nodes

• Simultaneous setup of multiple isolated networks

• Ideal for Golang unit tests

• Can run in workflows powered by GitHub's runners

• Lean code thanks to functional options

• Full IPv6 support

• Per link network emulation and bandwidth limiting via for Netem and TBF queuing disciplines

• Use of existing network namespaces as nodes

• Configuration of per-host nftables firewall rules

• Built-in Ping & Traceroute diagnostic tools

• Built-in packet tracing with PCAPng output

  • Automatic decryption of captured trafic using Wireshark/thark by including session secrets in PCAPng file
  • Automatic instrumentation of sub-processes using SSLKEYLOGFILE environment variable

Examples

Have a look at the unit tests for usage examples:

• Ping
• Run
• NAT
• Switch
• Links
• Firewall Rules
• Packet tracing
  • With TLS decryption

Prerequisites

• Go version 1.19 or later
• traceroute (for testing)
• libpcap (for compiling BPF filter expressions of packet tracing feature)

Architecture

Credits

• Steffen Vogel 📧

Funding acknowledment

The development of Gont has been supported by the ERIGrid 2.0 project
of the H2020 Programme under Grant Agreement No. 870620