Optimism Local Devnet in VM

This is a quick guide on how to setup your own local Optimism devnet. In order to run the Optimism ecosystem several tools are required like:

docker
geth
foundry
nodejs
pnpm

If you follow this guide, you end up with a virtual machine that contains the whole devnet and exposes the RPC ports of the chains to your host machine. This allows you to interact with the devnet from your host machine.

Prerequisites

1. QEMU and KVM

Assuming you have a virtualizable system (most are nowadays) you can install QEMU with the following commands:

sudo apt update
sudo apt install qemu-kvm virt-manager virtinst libvirt-clients bridge-utils libvirt-daemon-system -y

Next we start the libvirt virtualization daemon:

sudo systemctl enable --now libvirtd
sudo systemctl start libvirtd

Lastly, add the user to the kvm and libvirt groups:

sudo usermod -aG kvm $USER
sudo usermod -aG libvirt $USER

For a more complete installation guide, see here.

2. Start the devnet

Now you have two options: you can either use a prebuilt VM that contains all the necessary components or you can build the VM yourself. The prebuilt VM is the easiest option, but it is also the least flexible and might not have the most up-to-date version of the devnet. If you want to customize the devnet, you should build the VM yourself.

Option 1: Use a prebuilt VM (Easy)

Download the prebuit VM here. The password for the download is sandbox. Once downloaded you have a file called devnet.qcow2. This is the VM image that contains a light weight Ubuntu server and all the necessary components of the Optimism ecosystem.

To start the VM run the bash script start_devnet that is provided in this repository:

start_devnet devnet

The VM runs with 16GB of RAM and 4 CPUs but depending on your host machine you can change these values in the bash script.

And that's it! You now have a running devnet. You can ssh into the VM using the following command: ssh sandbox@127.0.0.1 -p 10022. Password is sandbox.

Further you can connect to the Ethereum chain and Optimism chain through the following RPC ports:

Chain	RPC Port
L1	8545
L2	9545

Option 2: Build the VM yourself (More flexible)

First, let's create a base disk image that we will base our devnet VM on. This can be done with the following command:

qemu-img create -f qcow2 base_vm.qcow2 80G

Next, we will download the Ubuntu server image. You can also choose a different distribution however this guide is tailored for Ubuntu. Once we have the iso file downloaded, we can start the installation process with the following command:

qemu-system-x86_64 -hda base_vm.qcow2 -cdrom ~/Downloads/ubuntu-22.04.2-live-server-amd64.iso -m 8192

I recommend setting up a user with the username sandbox and password sandbox so that the scripts in this repositiory remain compatible.

Now we have Ubuntu installed on the disk image. Let's now create a new fesh VM that contains the Optimism devnet.

Run the script create_devnet that is provided in this repository which will install all the required dependencies. The first argument is our base disk image and the second argument is the name of the new VM:

create_devnet base_vm devnet