rhyzome

Rhyzome

This is the Entanglement Garden component for provisioning VMs using libvirt.

there are two binaries: rhyzome-server, which runs in the cloud, and rhyzome, which runs on the Linux hypervisor next to libvirt.

It facilates the creation of virtual machines and unikernels.

Build

requires

• Go >=1.19
• libvirt-headers >=5.0.0

Build with make

Architecture

A REST server (rhyzome-server) accepts JWT-authenticated requests, stores the expected state in a sqlite database. It also creates a gRPC listener. On or more nodes, the client (rhyzome-agent) runs and connects to the gRPC listener, registering the node with the server. The client then listens for events from the server. The server initially sends all expected state (ie. all volumes and VMs that are supposed to be on the host) to the client, then sends new updates as they come in.

Installing

rhyzome-agent needs a libvirt hook installed. This requires several things:

• the rhyzome-agent binary should be available in the $PATH. I put it in /usr/local/bin/rhyzome-agent
• the actual hook, at /etc/libvirt/hooks/qemu.d/rhyzome must be a shell script (per libvirt docs). Here's mine:

#!/bin/bash
rhyzome-agent hook $@

• apparmor should allow libvirt to update it. I added this line to /etc/apparmor.d/local/usr.sbin.libvirtd:

/usr/local/bin/rhyzome-agent ix,

• /var/run/rhyzome-agent must exist and be accessible by the user rhyzome-agent is running as

Bootstrapping

TODO: rewrite this, everything's changed. See ../rhyzome-installer.git for the start (first stage) of the bootstrapping process. Second and third stage are handled in bootstrapping/ in this repo.

Dev setup

The server component can be tested locally with containers just like most of the other parts of rhyzome.

The client component must run on a system with libvirt and openvswitch, both of which I installed on my dev machine. To develop on the client, bring up the server with the rest of the services like normal (use start-services.sh in the local dev repo), copy rhyzome.localdev.json to rhyzome.json and run the client with go run ./cmd/rhyzome-agent.