lighthouse/scripts/local_testnet

Simple Local Testnet

These scripts allow for running a small local testnet with a default of 4 beacon nodes, 4 validator clients and 4 Geth execution clients using Kurtosis. This setup can be useful for testing and development.

Installation

1. Install Docker. Verify that Docker has been successfully installed by running sudo docker run hello-world.

2. Install Kurtosis. Verify that Kurtosis has been successfully installed by running kurtosis version which should display the version.

3. Install yq. If you are on Ubuntu, you can install yq by running snap install yq.

Starting the testnet

To start a testnet, from the Lighthouse root repository:

cd ./scripts/local_testnet
./start_local_testnet.sh

It will build a Lighthouse docker image from the root of the directory and will take an approximately 12 minutes to complete. Once built, the testing will be started automatically. You will see a list of services running and "Started!" at the end. You can also select your own Lighthouse docker image to use by specifying it in network_params.yml under the cl_image key. Full configuration reference for Kurtosis is specified here.

To view all running services:

kurtosis enclave inspect local-testnet

To view the logs:

kurtosis service logs local-testnet $SERVICE_NAME

where $SERVICE_NAME is obtained by inspecting the running services above. For example, to view the logs of the first beacon node, validator client and Geth:

kurtosis service logs local-testnet -f cl-1-lighthouse-geth 
kurtosis service logs local-testnet -f vc-1-geth-lighthouse
kurtosis service logs local-testnet -f el-1-geth-lighthouse

If you would like to save the logs, use the command:

kurtosis dump $OUTPUT_DIRECTORY

This will create a folder named $OUTPUT_DIRECTORY in the present working directory that contains all logs and other information. If you want the logs for a particular service and saved to a file named logs.txt:

kurtosis service logs local-testnet $SERVICE_NAME -a > logs.txt

where $SERVICE_NAME can be viewed by running kurtosis enclave inspect local-testnet.

Kurtosis comes with a Dora explorer which can be opened with:

open $(kurtosis port print local-testnet dora http)

Some testnet parameters can be varied by modifying the network_params.yaml file. Kurtosis also comes with a web UI which can be open with kurtosis web.

Stopping the testnet

To stop the testnet, from the Lighthouse root repository:

cd ./scripts/local_testnet
./stop_local_testnet.sh

You will see "Local testnet stopped." at the end.

CLI options

The script comes with some CLI options, which can be viewed with ./start_local_testnet.sh --help. One of the CLI options is to avoid rebuilding Lighthouse each time the testnet starts, which can be configured with the command:

./start_local_testnet.sh -b false

Further reading about Kurtosis

You may refer to this article for information about Kurtosis.