Polycube Developers Guide

This guide represents an initial starting point for developers that want to implement new services (e.g., custom NAT, router, etc) using the Polycube software infrastructure.

Contents:

• Writing the eBPF datapath
  • Processing packets in the slowpath
  • Checksum calculation
  • VLAN Support
  • Timestamping
  • Known limitations
  • Debugging the data plane
• Writing the control plane
  • Handling eBPF programs
  • Adding and removing ports
  • eBPF maps API
  • Implementing the control path
  • Debugging the control plane
• Writing a YANG data model
• Polycube Automatic Code Generation Tools
  • Generating a service stub
• Debugging Polycube services
  • Configuring logging levels
  • Logging the eBPF data plane
  • Logging the control plane
• Debugging using Integrated Development Environment (IDE)
  • VS Code
  • CLion
• Debugging network traffic using tcpdump/Wireshark
• Profiler Framework
  • Introduction
  • How it works
  • Usage
  • Example
  • Performance analysis
• Hints for programmers
  • Compiling a Polycube service
  • Loading/unloading Polycube services at runtime
  • Install the provided git-hooks
  • How to write a test
  • Optimizing the compilation time of dataplane eBPF programs
  • Additional hints
  • Continuous Integration
  • Valgrind
• Hateoas
  • What can Hateoas be used for?
  • How to use Hateoas
  • Example
  • How to know endpoints without hateoas?
• Polycube CI/CD
  • Introduction
  • Implementation with polycube
  • Workflow in “dev” state
  • Workflow in “master” state
  • Workflow in “release” state

How to create a new service / update an existing one

The process to create or update service could be summarized in these steps:

1. Write or update a datamodel for the service

2. Use the datamodel for generating a service stub or updating an existing service stub

3. Implement or update the eBPF datapath

4. Implement or update the control plane

Please note that steps (1) and (2) are needed only when there is a change to the the YANG data model. In case we have to slightly modify an existing service (e.g., fixing a bug in the code), only steps (3) and (4) are required.