Guide to Staking on Ethereum 2.0 (Ubuntu/Medalla/Lighthouse)

Somer Esat

Aug 3, 2020·27 min read

***
NOTE: This guide is now deprecated. Please use the newer version targeting the Pyrmont testnet.

*** located here.

This is a step-by-step guide to staking on the Ethereum 2.0 Medalla multi-client testnet via the Sigma Prime Lighthouse client. It is based on the following technologies:

• Ubuntu v20.04 (LTS) x64 server
• Go Ethereum Node (code branch)
• Sigma Prime’s Ethereum 2.0 client, Lighthouse (code branch)
• Official multi-client testnet public network, Medalla
• MetaMask crypto wallet browser extension
• Prometheus metrics
• Grafana dashboard

This guide includes instructions on how to:

• Configure a newly running Ubuntu server instance.
• Configure and run an Ethereum 1.0 node as a service.
• Compile and configure the Lighthouse client software for Ethereum 2.0, Phase 0 (Medalla testnet) and run as a service.
• Install and configure Prometheus metrics and set up a Grafana dashboard.

WARNING

This guide is for the Medalla testnet. DO NOT, under any circumstances, send real ETH to this testnet. You will lose it.

Acknowledgements and Disclaimer

This guide is based on information I pulled together from various on-line resources and this guide wouldn’t exist without them. Thank you, all!

And a special Thank You to the client team and the EF researchers. Your tireless efforts over the past few years have brought us to the cusp of an incredible moment in history — the launch of Ethereum 2.0.

This guide is for educational purposes only. I’m not an expert in any of the technologies used in this guide. I got it working and it’s a lot of fun, so I wanted to share it with others. Please forgive any errors or ill-informed choices. The accuracy of this guide is not guaranteed. Feedback is always welcome!

Support

This stuff can be tricky. If you need help there are two great resources you can reach out to:

• EthStaker community on Reddit or Discord. Knowledgeable and friendly community passionate about staking on Ethereum 2.0.
• Lighthouse client team Discord. The client software engineering team. Experts on Lighthouse and its usage.

Prerequisites

This guide is not intended for absolute beginners. It assumes some knowledge of Ethereum, ETH, staking, Linux, and MetaMask. Before you get started you will need to have your Ubuntu server instance up and running. It will help to have the MetaMask browser extension installed and configured somewhere. The rest we will do along the way.

Note for Raspberry Pi Users

I haven’t tested this guide on a Rpi. If you want to try, just swap out the software listed below for the ARM version, where available. No guarantee it will work!

Requirements

• Ubuntu server instance. I used v20.04 (LTS) amd64 server VM.
• MetaMask crypto wallet browser extension, installed and configured.
• I wasn’t able to find information on hardware requirements, but this client is known to run well on min spec systems (e.g. Raspberry Pi). Note that compilation of the software requires a bit of grunt and may take a fair amount of time on a low-end system.
• I used a VM with the following specs:
  - Intel(R) Xeon(R) Gold 6140 CPU @ 2.30GHz
  - 4 GB RAM
  - 80GB SSD

Overview

This is a long and detailed guide. Here’s a super simplified diagram to help you conceptualize what we are going to do. The yellow boxes are the parts this guide mostly covers.

The conceptual flow is:

• Set up a Eth1 node and sync it with the Eth1 Goerli testnet
• Generate and activate validator keys
• Configure the Beacon Node and Validator Client
• The Beacon Node makes the magic happen (blocks, attestations, etc.) with the help of the validator (signing).

***
NOTE: This guide is now deprecated. Please use the newer version targeting the Pyrmont testnet.

*** located here.

Step 0 — Connect to the Server

Using a SSH client, connect to your Ubuntu server. The root user account on Ubuntu server is normally disabled by default, however some cloud providers enable it. If you are logged in as root then let’s create a user-level account with admin privileges instead, because using the root user to log in is risky.

NOTE: If you are not logged in as root then skip this and go to Step 1.

# adduser <yourusername>

You will asked to create a password and some other information.

Grant admin rights to the new user by adding it to the sudo group.

# usermod -aG sudo <yourusername>

When you log in as <yourusername> you can type sudo before commands to perform actions with superuser privileges.

Optional: If you used SSH keys to connect to your Ubuntu instance via the root user you will need to associate the new user with the root user’s SSH key data.

# rsync --archive --chown=<yourusername>:<yourusername> ~/.ssh /home/<yourusername>

Finally, log out of root and log in as <yourusername>.

Step 1 — Update Your System

Make sure your system is up to date with the latest software and security updates.

$ sudo apt update && sudo apt upgrade
$ sudo apt dist-upgrade && sudo apt autoremove

Step 2— Secure Your System

Security is important. This is not a comprehensive security guide, rather just some basic settings.

Configure the firewall

Ubuntu 20.04 servers can use the default UFW firewall to restrict traffic to the server. We need to allow inbound traffic for SSH, Go Ethereum, Grafana, and Lighthouse.

Allow SSH
Allows connection to the server over SSH. For security reasons we are going to modify the default port of 22 because it is a common attack vector.

Note: If you would rather not change the default SSH port (not recommended), then include a rule allowing the default SSH port $ sudo ufw allow 22/tcp and move onto the “Allow Go Ethereum” section.

Choose a port number between 1024–49151 and run the following command to make sure your selection is not already in use on the server. If it is (red text), choose a different port.

$ sudo ss -tulpn | grep ':<yourSSHportnumber>'

Update the firewall to allow inbound traffic on <yourSSHportnumber>. SSH requires TCP.

$ sudo ufw allow <yourSSHportnumber>/tcp

Next change the default SSH port.

$ sudo nano /etc/ssh/sshd_config

Find the line with # Port 22 or Port 22 and change it to Port <yourSSHportnumber>. Remove the # if it was present.

Check the screen shot below for reference. Your file should look similar to that (but with the port number you chose). Exit and save.

Restart the SSH service.

$ sudo systemctl restart ssh

Next time you log in via SSH use <yourSSHportnumber> for the port.

Optional: If you were already using UFW with port 22/TCP allowed then update the firewall to deny inbound traffic on that port.

$ sudo ufw deny 22/tcp

Allow Go Ethereum
Allows incoming requests from Go Ethereum peers (port 30303/TPC and 30303/UDP). If you’d rather use a node hosted by a 3rd party (Infura, etc.) then skip this step.

Note: If you are hosting your Ubuntu instance locally your internet router and/or firewall will need to be configured to allow incoming traffic on these ports as well.

$ sudo ufw allow 30303

Allow Lighthouse
Allows P2P connections with peers for actions on the beacon node (ports 9000/TCP and 9000/UDP).

Note: If you are hosting your Ubuntu instance locally your internet router and/or firewall will need to be configured to allow incoming traffic on these ports as well.

$ sudo ufw allow 9000

Allow Grafana
Allows incoming requests to the Grafana web server (port 3000/TCP).

$ sudo ufw allow 3000/tcp

Allow Prometheus (Optional)
If you want direct access to the Prometheus data service you can open up port 9090/TCP as well. This is not necessary if you are solely using Grafana to view the data. I did not open this port.

$ sudo ufw allow 9090/tcp

Now enable the firewall and check to verify the rules have been correctly configured.

$ sudo ufw enable
$ sudo ufw status numbered

Output should look something like this.

Step 3 — Configure ntpd Timekeeping (Optional)

Ubuntu has time synchronization built in and activated by default using systemd’s timesyncd service. However, for applications that require more precise timekeeping (like a blockchain) we will use ntpd.

First, we must disable timesyncd and verify it is off. Output should show NTP service: inactive.

$ sudo timedatectl set-ntp no
$ timedatectl

Next, install the ntp package. It will be started automatically after install. Verify the package.

$ sudo apt install ntp
$ ntpq -p

Output should look like this:

We can further verify the service is running as expected.

$ ntpq -c rv

Results in:

ethstaker@ETH-STAKER-001:~$ ntpq -c rv
associd=0 status=0615 leap_none, sync_ntp, 1 event, clock_sync,
version="ntpd 4.2.8p12@1.3728-o (1)", processor="x86_64",
system="Linux/5.4.0-48-generic", leap=00, stratum=2, precision=-24,
rootdelay=1.453, rootdisp=8.653, refid=209.51.161.238,
reftime=e315548b.d020811b  Wed, Sep 23 2020  4:58:51.812,
clock=e31554cf.99ddcf68  Wed, Sep 23 2020  4:59:59.601, peer=5978, tc=6,
mintc=3, offset=3.040122, frequency=6.453, sys_jitter=2.164815,
clk_jitter=2.062, clk_wander=0.539, tai=37, leapsec=201701010000,
expire=202012280000

In the output (2nd line) we have leap_none. This is the Leap Field and the value (leap_none) is a code that indicates we have a normal synchronized state.

In the output (2nd line) we have sync_ntp. This is the Source Field and the value (sync_ntp) is a code that indicates we are using NTP.

In the output (2nd line) we have clock_sync. This is the Event Field and the value (clock_sync) is a code that indicates the clock is synchronized.

If you have different codes to these check here to see a list of possible values. Resolve any issues as necessary.

***
NOTE: This guide is now deprecated. Please use the newer version targeting the Pyrmont testnet.

*** located here.

Step 4— Install and Run Go Ethereum Node

Install and configure an Ethereum 1.0 node that the Lighthouse beacon node will connect to. If you’d rather use a node hosted by a 3rd party (Infura, etc.) then skip this step.

Install Go Ethereum

Go Ethereum recommends using PPA’s (Personal Package Archives).

$ sudo add-apt-repository -y ppa:ethereum/ethereum

Update the packages and install the latest stable version.

$ sudo apt update
$ sudo apt install geth

Run Go Ethereum as a Background Service

Create an account for the service to run under. This type of account can’t log into the server.

$ sudo useradd --no-create-home --shell /bin/false goeth

Create the data directory for the Eth1 chain. This is required for storing the Eth1 node data. Use the -p option to create the full path.

$ sudo mkdir -p /var/lib/goethereum

Set directory permissions. The goeth account needs permission to modify the data directory.

$ sudo chown -R goeth:goeth /var/lib/goethereum

Create a systemd service file to store the service config. We will use the config file to tell systemd to run the geth process.

$ sudo nano /etc/systemd/system/geth.service

Paste the following service configuration into the file.

[Unit]
Description=Ethereum go client
After=network.target 
Wants=network.target[Service]
User=goeth 
Group=goeth
Type=simple
Restart=always
RestartSec=5
ExecStart=geth --goerli --http --datadir /var/lib/goethereum[Install]
WantedBy=default.target

The --goerli flag is used to target the Göerli test network and the --http flag is to expose an endpoint (http://localhost:8545) that the beacon chain will connect to.

Check the screen shot below for reference. Your file should look like that. Exit and save.

Reload systemd to reflect the changes.

$ sudo systemctl daemon-reload

Start the service and check to make sure it’s running correctly.

$ sudo systemctl start geth
$ sudo systemctl status geth

Output should look like this.

If you did everything right, it should say active (running) in green text. If not then go back and repeat the steps to fix the problem. Press Q to quit.

Enable the geth service to automatically start on reboot.

$ sudo systemctl enable geth

The Go Ethereum node will begin to sync. You can follow the progress by running the journal command. Press Ctrl+C to quit.

$ sudo journalctl -f -u geth.service

Sometimes it can take a while to find peers to sync. If so, you can add some peers to help things along. Go here for the latest list and modify the geth service as follows:

$ sudo systemctl stop geth
$ sudo nano /etc/systemd/system/geth.service

Modify the ExecStart line and add the --bootnodes flag with a few of the latest peers (comma separated).

ExecStart=geth --goerli --http --datadir /var/lib/goethereum --bootnodes "enode://46add44b9f13965f7b9875ac6b85f016f341012d84f975377573800a863526f4da19ae2c620ec73d11591fa9510e992ecc03ad0751f53cc02f7c7ed6d55c7291@94.237.54.114:30313,enode://119f66b04772e8d2e9d352b81a15aa49d565590bfc9a80fe732706919f8ccd00a471cf8433e398c55c4862aadb4aadf3a010201483b87e8358951698aa0b6f07@13.250.50.139:30303"

Save the file and exit. Restart the service and observe.

$ sudo systemctl daemon-reload
$ sudo systemctl start geth
$ sudo journalctl -f -u geth.service

Once it gets started the output should look like this.

Note: You should wait for the node sync to complete before you run the beacon chain. You can see the latest block here.

For example, the screen shot above shows the node is processing block number=498880 and looking at the screen shot below, we can see the latest block number is 3270051. So based on that we still have a while to go before completing the sync.

Next we will clone and build the Lighthouse software. Consider opening a new terminal window here so you can continue to observe the Eth1 node sync.

Step 5— Install Dependencies

Rust is required to build Lighthouse. Follow the prompts to install.

$ curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

Since Rust modifies the PATH variable you will need to log out and log back in again or you may get a command not found error like the one below when trying to compile. Alternatively, instead of relogging you can run source $HOME/.cargo/env.

cargo install --path lighthouse --force --locked
make: cargo: Command not found
make: *** [Makefile:20: install] Error 127

A number of packages (git, gcc, g++, make, cmake, etc) are also required.

$ sudo apt install -y git gcc g++ make cmake pkg-config libssl-dev

***
NOTE: This guide is now deprecated. Please use the newer version targeting the Pyrmont testnet.

*** located here.

Step 6— Install and Build Lighthouse

Now we’re ready to build Lighthouse. The Lighthouse build produces a lighthouse binary. We execute the same binary with different subcommands to get the functionality we need. E.g.:

lighthouse beacon_node will run a beacon node instance.

lighthouse validator_client will run a validator client instance.

Clone the Lighthouse main repository.

$ cd ~
$ git clone https://github.com/sigp/lighthouse.git
$ cd lighthouse

Use Make to compile the Lighthouse binary.

$ make

Output looks like this.

Depending on your hardware it can take a while to build. Good time to get a fresh beverage and re-hydrate. Maybe check out a few of my other articles.

If the build succeeds then continue. If not get help on the Lighthouse Discord.

Step 7— Complete the Medalla On-boarding Process

In order to run a validator on the Eth2.0 Medalla testnet we will need to sign up for one or more validator accounts.

NOTE: If you have already generated your deposit data and submitted your staking deposits you can skip this step. This guide assumes the validator key files are stored on the Ubuntu server here: $HOME/eth2.0-deposit-cli/validator_keys.

The steps to sign-up are:

• Get Göerli ETH
• Generate the validator keys. Each key is a validator account
• Fund the validator account(s) with 32 Göerli ETH per account
• Wait for your validator account(s) to become active

Let’s get started.

Get Goerli ETH

1. Go to a computer with the MetaMask browser extension installed.
2. Click on MetaMask and log in.
3. Using the drop-down at the top, select the Göerli Test Network.
4. Click on the account name to copy your Göerli Test Network wallet address.
5. Using your address, get Göerli ETH from the authenticated faucet or via the #request-goerli-eth channel on the ethstaker Discord using the bot command: !goerliEth <yourwalletaddress>.

NOTE: Each validator requires a 32 ETH deposit. You should have sufficient Göerli ETH in your MetaMask wallet to fund each validator. For example, if you want 10 validators you need to have 320 Göerli ETH plus some extra (e.g. 1 Göerli ETH) to pay for the gas fees.

Generate Validator Keys

Next we will generate the validator keys. The validator client supports multiple validator keys. Each validator key is basically a “validator account” on the Medalla testnet.

Clone the deposit generator client.

$ cd ~
$ git clone https://github.com/ethereum/eth2.0-deposit-cli.git
$ cd eth2.0-deposit-cli

Check the Python version (Python 3.7 and above is required).

$ python3 -V

If you don’t have Python (or have a version below 3.7), follow these steps.

$ sudo apt install software-properties-common
$ sudo add-apt-repository ppa:deadsnakes/ppa
$ sudo apt update
$ sudo apt install python3.7

Install the prerequisites.

$ sudo apt install python3-pip

Install the application to generate the validator keys.

Change <numberofvalidators> to the number of validator keys you want to create. E.g. --num_validators 5.

$ sudo ./deposit.sh install
$ ./deposit.sh new-mnemonic --num_validators <numberofvalidators> --mnemonic_language=english --chain medalla

After running this step you should have a deposit JSON file, some validator key JSON files, a password, and a mnemonic seed phrase. You should back up all of these somewhere safe.

Success!
Your keys can be found at: /home/<yourusername>/eth2.0-deposit-cli/validator_keys

Copy Deposit Data File

In the validator_keys directory there will be a deposit_data-[timestamp].json file. You will need to upload this via a website in the next step. Since we are on a server we don’t have a web browser so secure FTP (SFTP) the file to a desktop computer that does.

Fund the Validator Keys

This step involves depositing the required amount of Göerli ETH to the Medalla testnet staking contract. This is done on the Eth2.0 Lauchpad website.

WARNING: DO NOT send real ETH to the Medalla testnet. You will lose your ETH.

Go here: https://medalla.launchpad.ethereum.org/

Click through the warning steps then select the number of validators you are going to run. Scroll down and click continue.

You will be asked to upload the deposit_data-[timestamp].json file. Browse or drag the file and click continue.

Connect your wallet. Choose MetaMask, log in, select the Göerli Test Network and click Continue.

WARNING: Be absolutely 100% sure you have selected the Göerli Test Network in MetaMask. DO NOT sent real ETH to the Medalla testnet.

Your MetaMask balance will be displayed. The site will allow you to continue if you have sufficient Göerli ETH balance.

A summary shows the number of validators and total amount of Göerli ETH required. Tick the boxes if you agree and click continue.

Click on initiate all transactions. This will pop open multiple instances of MetaMask, each with a 32 Göerli ETH transaction request to the Medalla testnet deposit contract. Confirm each transaction.

Once all the transactions have successfully completed you are done!

Check the Status of Your Validators

Newly added validators can take a while (hours/days/weeks) to activate. You can check the status of your keys with these steps:

1. Copy your Göerli Test Network wallet address
2. Go here: https://medalla.beaconcha.in/
3. Search your wallet address. Your keys will be shown.

Click on a key to see the Estimated Activation information.

That’s it! Now let’s create the validator wallet.

***
NOTE: This guide is now deprecated. Please use the newer version targeting the Pyrmont testnet.

*** located here.

Step 8 — Create the Validator Wallet

The validator wallet is created by importing the keystore-m JSON files from the previous step.

First create a directory to store the validator wallet and give the current user permissions to access it. Change <yourusername> to your logged in username.

$ sudo mkdir -p /var/lib/lighthouse
$ sudo chown -R <yourusername>:<yourusername> /var/lib/lighthouse

Next, run the wallet creation process. The account validator import expects the keystore-m JSON keys to be in the directory HOME/eth2.0-deposit-cli/validator_keys.

$ cd ~
$ cd lighthouse
$ lighthouse --testnet medalla account validator import --directory $HOME/eth2.0-deposit-cli/validator_keys --datadir /var/lib/lighthouse

The --datadir flag specifies the location to output the wallet data. The process will create a validators directory under the --datadir path.

You will be asked to provide the password for each key, one-by-one. Be sure to provide the password each time because the validator will be running as a service, and it needs to persist the password in a file to access the key.

Output should look like:

Running account manager for medalla testnet
validator-dir path: "/var/lib/lighthouse/validators"
WARNING: DO NOT USE THE ORIGINAL KEYSTORES TO VALIDATE WITH ANOTHER CLIENT, OR YOU WILL GET SLASHED.Keystore found at "/home/<yourusername>/eth2.0-deposit-cli/validator_keys/keystore-m_12381_3600_11_0_0-1596123063.json":- Public key: 0xa824a80e630a93b7132c58d9626d2b6d67c277196b655bc5665f4f0f0a6abed5d64c7cb5a2de4e19e7b70d5a2b85db4a
 - UUID: 74f797e7-3946-45cf-9c76-6630a75ca2f5If you enter the password it will be stored as plain-text in validator_definitions.yml so that it is not required each time the validator client starts.Enter the keystore password, or press enter to omit it:Password is correct.Successfully imported keystore.
Successfully updated validator_definitions.yml.

Once you do this for each keystore-m JSON file you should get a successful message.

Successfully imported 40 validators (0 skipped).WARNING: DO NOT USE THE ORIGINAL KEYSTORES TO VALIDATE WITH ANOTHER CLIENT, OR YOU WILL GET SLASHED.

For security reasons, update permissions to remove access to var/lib/lighthouse for <youruseraccount>. This is intentionally not using -R as we will reassign permissions to the sub-directories later.

sudo chown root:root /var/lib/lighthouse

That’s it! Now that the validator wallet is configured we will set up the beacon node and validator.

Step 9— Configure the Beacon Node

We will run the beacon node as a service so if the system restarts the process will automatically start back up again.

Setup Accounts and Directories

Create an account for the beacon node to run under. This type of account can’t log into the server.

$ sudo useradd --no-create-home --shell /bin/false lighthousebeacon

Create the data directory for the Lighthouse beacon node database.

$ sudo mkdir -p /var/lib/lighthouse/beacon

Set directory permissions. The lighthousebeacon account needs permission to modify the database directory.

$ sudo chown -R lighthousebeacon:lighthousebeacon /var/lib/lighthouse/beacon

Next, copy the compiled lighthouse binary (from Step 6) to the /usr/local/bin directory. We will run it from there.

Note: You will need to do this step each time you pull/build a new version of the lighthouse binary. See Appendix — Updating Lighthouse at the end of this guide

$ sudo cp /$HOME/.cargo/bin/lighthouse /usr/local/bin

Create and Configure the Service

Create a systemd service file to store the service config.

$ sudo nano /etc/systemd/system/lighthousebeacon.service

Paste the following into the file.

[Unit]
Description=Lighthouse Beacon Node
Wants=network-online.target
After=network-online.target[Service]
Type=simple
User=lighthousebeacon
Group=lighthousebeacon
Restart=always
RestartSec=5
ExecStart=/usr/local/bin/lighthouse beacon_node --datadir /var/lib/lighthouse --testnet medalla --staking --eth1-endpoint http://127.0.0.1:8545 --metrics[Install]
WantedBy=multi-user.target

The beacon_node subcommand tells the lighthouse binary that we want to run the beacon node.

The --datadir flag is the path to store the beacon node database.

The --staking flag indicates that we are also going to be running a validator, therefore enabling the HTTP server. The validator and beacon node use that to communicate with each other.

The --eth1-endpoint flag defines the endpoint of the Eth1 node. If you installed one locally the value is http://127.0.0.1:8545. If you’re using a third party change the value to point to the external endpoint address.

The --metrics flag enables a metrics server on port 5054. The output will be captured by Prometheus.

Check the screen shot below for reference. Your file should look like that. Exit and save.

Reload systemd to reflect the changes.

$ sudo systemctl daemon-reload

Note: If you are running a local Eth1 node (see Step 4) you should wait until it fully syncs before starting the beacon chain service. Check progress here: sudo journalctl -f -u geth.service

Start the service and check to make sure it’s running correctly.

$ sudo systemctl start lighthousebeacon
$ sudo systemctl status lighthousebeacon

Output should look like this.

If you did everything right, it should say active (running) in green text. If not then go back and repeat the steps to fix the problem. Press Q to quit.

Enable the beacon-chain service to automatically start on reboot.

$ sudo systemctl enable lighthousebeacon

The beacon-chain will begin to sync. It may take several hours for the node to fully sync. You can check the progress by running the journal command. Press Ctrl+C to quit.

$ sudo journalctl -f -u lighthousebeacon.service

The output will give an indication of time to fully sync.

Aug 30 00:12:50 ETH-STAKER-001 lighthouse[29743]: Aug 30 00:12:50.001 INFO Syncing                                 est_time: 4 hrs 38 mins, speed: 10.67 slots/sec, distance: 178499 slots (3 weeks 3 days), peers: 49, service: slot_notifier

Now your beacon chain is running as a service. Congratulations! While the beacon node is syncing, let’s move onto the next step.

***
NOTE: This guide is now deprecated. Please use the newer version targeting the Pyrmont testnet.

*** located here.

Step 10 — Configure the Validator

Setup Accounts and Directories

We will run the validator as a service so if the system restarts the process will automatically start back up again.

Create an account for the validator service to run under. This type of account can’t log into the server.

$ sudo useradd --no-create-home --shell /bin/false lighthousevalidator

We created the data directory for the validator in the wallet creation step: /var/lib/lighthouse/validators. Now set directory permissions so the lighthousevalidator account can modify the validator account data directory.

$ sudo chown -R lighthousevalidator:lighthousevalidator /var/lib/lighthouse/validators

Create and Configure the Service

Create a systemd service file to store the service config.

$ sudo nano /etc/systemd/system/lighthousevalidator.service

Paste the following into the file.

[Unit]
Description=Lighthouse Validator
Wants=network-online.target
After=network-online.target[Service]
Type=simple
User=lighthousevalidator
Group=lighthousevalidator
Restart=always
RestartSec=5
ExecStart=/usr/local/bin/lighthouse validator_client --datadir /var/lib/lighthouse --graffiti "<yourPOAPstring>"[Install]
WantedBy=multi-user.target

Replace <yourPOAPstring> with your Lighthouse POAP participation medal value for a special NFT prize! E.g. --graffiti "abcdefg12345saf"

We use the same lighthouse binary located in /usr/local/bin but this time we apply the validator_client subcommand, instructing it to run the validator.

The --datadir flag is where we are going to save our validator database.

Check the screen shot below for reference. Exit and save.

Reload systemd to reflect the changes.

$ sudo systemctl daemon-reload

Start the service and check to make sure it’s running correctly.

$ sudo systemctl start lighthousevalidator
$ sudo systemctl status lighthousevalidator

You should see output that looks something like this.

If you did everything right, it should say active (running) in green text. If not then go back and repeat the steps to fix the problem. Press Q to quit.

Enable the validator service to automatically start on reboot.

$ sudo systemctl enable lighthousevalidator

You can check the progress by running the journal command. Press Ctrl+C to quit.

$ sudo journalctl -f -u lighthousevalidator.service

The validator will enable the validator keys in the validator wallet and confirm the connection to the beacon node. If the testnet genesis hasn’t begun yet it will tell us how much time is remaining.

Aug 30 00:42:00 ETH-STAKER-001 lighthouse[30051]: Aug 30 00:42:00.547 INFO Enabled validator                       voting_pubkey: 0xb5345654d5203c0dbaaf5eb0403617de9cf8db092d6966c0cb4b79c7b7fb05efe90f6a7b6aa02137b1c1729cff593751
Aug 30 00:42:02 ETH-STAKER-001 lighthouse[30051]: Aug 30 00:42:02.093 INFO Enabled validator                       voting_pubkey: 0xa812a70e730a93b7132c58d9626d2b6d67c277196b655bc5665f4f0f0a6abed5d64c7cb5a2de4e19e7b70d5a2b55db3a

It may take hours or even days to activate the validator account(s) on the testnet once the beacon chain has actually started processing.

If your beacon node is still syncing to the Eth1 chain head you will see this message:

Aug 30 00:42:38 ETH-STAKER-001 lighthouse[30051]: Aug 30 00:42:38.002 ERRO Beacon node is syncing                  current_slot: 20864, target_slot: 183424, msg: not receiving new duties, service: notifier

You can check the status of your validator(s) via beaconcha.in. Simply do a search for your validator public key(s) or search using your MetaMask wallet address. It may be a while before they appear on the site.

That’s it. We have a functioning beacon chain and validator. Congratulations: you are awesome!

Step 11 — Install Prometheus

Prometheus is an open-source systems monitoring and alerting toolkit. It runs as a service on your Ubuntu server and its job is to capture metrics. More information here.

We are going to use Prometheus to expose runtime data from the beacon-chain and validator as well as instance specific metrics.

Create User Accounts

Accounts for the services to run under. These accounts can’t log into the server.

$ sudo useradd --no-create-home --shell /bin/false prometheus
$ sudo useradd --no-create-home --shell /bin/false node_exporter

Create Directories

Program and data directories.

$ sudo mkdir /etc/prometheus
$ sudo mkdir /var/lib/prometheus

Set directory ownership. The prometheus account will manage these.

$ sudo chown -R prometheus:prometheus /etc/prometheus
$ sudo chown -R prometheus:prometheus /var/lib/prometheus

Download Prometheus software

Adjust the version number to the latest version from the Prometheus download page. Rpi users be sure to get the ARM binary.

$ cd ~
$ curl -LO https://github.com/prometheus/prometheus/releases/download/v2.20.0/prometheus-2.20.0.linux-amd64.tar.gz

Unpack the archive. It contains two binaries and some content files.

$ tar xvf prometheus-2.20.0.linux-amd64.tar.gz

Copy the binaries to the following locations.

$ sudo cp prometheus-2.20.0.linux-amd64/prometheus /usr/local/bin/
$ sudo cp prometheus-2.20.0.linux-amd64/promtool /usr/local/bin/

Set directory ownership. The prometheus account will manage these.

$ sudo chown -R prometheus:prometheus /usr/local/bin/prometheus
$ sudo chown -R prometheus:prometheus /usr/local/bin/promtool

Copy the content files to the following locations.

$ sudo cp -r prometheus-2.20.0.linux-amd64/consoles /etc/prometheus
$ sudo cp -r prometheus-2.20.0.linux-amd64/console_libraries /etc/prometheus

Set directory and file (-R) ownership. The prometheus account will manage these.

$ sudo chown -R prometheus:prometheus /etc/prometheus/consoles
$ sudo chown -R prometheus:prometheus /etc/prometheus/console_libraries

Remove the downloaded archive.

$ rm -rf prometheus-2.20.0.linux-amd64.tar.gz prometheus-2.20.0.linux-amd64

Edit the Configuration File

Prometheus uses a configuration file so it knows where to scrape the data from. We will set this up here.

Open the YAML config file for editing.

$ sudo nano /etc/prometheus/prometheus.yml

Paste the following into the file taking care not to make any additional edits and exit and save the file.

global:
  scrape_interval:     15s # Set the scrape interval to every 15 seconds. Default is every 1 minute.
  evaluation_interval: 15s # Evaluate rules every 15 seconds. The default is every 1 minute.
  # scrape_timeout is set to the global default (10s).
# Alertmanager configuration
alerting:
  alertmanagers:
  - static_configs:
    - targets:
      # - alertmanager:9093
# Load rules once and periodically evaluate them according to the global 'evaluation_interval'.
rule_files:
  # - "first_rules.yml"
  # - "second_rules.yml"
# A scrape configuration containing exactly one endpoint to scrape:
# Here it's Prometheus itself.
scrape_configs:
  - job_name: 'nodes'
    metrics_path: /metrics    
    static_configs:
      - targets: ['localhost:5054']
  - job_name: 'node_exporter'
    static_configs:
      - targets: ['localhost:9100']

The scrape_configs define the output target for the different job names. We have 2 job names: beacon node and node_exporter. The first is obvious, the second is for metrics related to the server instance itself (memory, CPU, disk, network etc.). We will install and configure node_exporter in the next step.

Set ownership for the config file. The prometheus account will own this.

$ sudo chown -R prometheus:prometheus /etc/prometheus/prometheus.yml

Finally, let’s test the service is running correctly.

$ sudo -u prometheus /usr/local/bin/prometheus \
    --config.file /etc/prometheus/prometheus.yml \
    --storage.tsdb.path /var/lib/prometheus/ \
    --web.console.templates=/etc/prometheus/consoles \
    --web.console.libraries=/etc/prometheus/console_libraries

Output should look something like this. Press Ctrl + C to exit.

level=info ts=2020-08-02T04:56:51.414Z caller=main.go:805 msg="Loading configuration file" filename=/etc/prometheus/prometheus.yml
level=info ts=2020-08-02T04:56:51.415Z caller=main.go:833 msg="Completed loading of configuration file" filename=/etc/prometheus/prometheus.yml
level=info ts=2020-08-02T04:56:51.415Z caller=main.go:652 msg="Server is ready to receive web requests."

Set Prometheus to Auto-Start as a Service

Create a systemd service file to store the service config which tells systemd to run Prometheus as the prometheus user, with the configuration file located in the /etc/prometheus/prometheus.yml directory, and to store its data in the /var/lib/prometheus directory.

$ sudo nano /etc/systemd/system/prometheus.service

Paste the following into the file. Exit and save.

[Unit]
Description=Prometheus
Wants=network-online.target
After=network-online.target[Service]
Type=simple
User=prometheus
Group=prometheus
Restart=always
RestartSec=5
ExecStart=/usr/local/bin/prometheus \
    --config.file /etc/prometheus/prometheus.yml \
    --storage.tsdb.path /var/lib/prometheus/ \
    --web.console.templates=/etc/prometheus/consoles \
    --web.console.libraries=/etc/prometheus/console_libraries[Install]
WantedBy=multi-user.target

Reload systemd to reflect the changes.

$ sudo systemctl daemon-reload

And then start the service with the following command and check the status to make sure it’s running correctly.

$ sudo systemctl start prometheus
$ sudo systemctl status prometheus

Output should look something like this.

If you did everything right, it should say active (running) in green. If not then go back and repeat the steps to fix the problem. Press Q to quit.

Lastly, enable Prometheus to start on boot.

$ sudo systemctl enable prometheus

Step 12 — Install Node Exporter

Prometheus will provide metrics about the beacon chain and validators. If we want metrics about our Ubuntu instance, we’ll need an extension called Node_Exporter. You can find the latest stable version here if you want to specify a different version below. Rpi users remember to get the ARM binary.

$ cd ~
$ curl -LO https://github.com/prometheus/node_exporter/releases/download/v1.0.1/node_exporter-1.0.1.linux-amd64.tar.gz

Unpack the downloaded software.

$ tar xvf node_exporter-1.0.1.linux-amd64.tar.gz

Copy the binary to the /usr/local/bin directory and set the user and group ownership to the node_exporter user we created above.

$ sudo cp node_exporter-1.0.1.linux-amd64/node_exporter /usr/local/bin
$ sudo chown -R node_exporter:node_exporter /usr/local/bin/node_exporter

Remove the downloaded archive.

$ rm -rf node_exporter-1.0.1.linux-amd64.tar.gz node_exporter-1.0.1.linux-amd64

Set Node Exporter to Auto-Start as a Service

Create a systemd service file to store the service config which tells systemd to run Node_Exporter as the node_exporter user.

$ sudo nano /etc/systemd/system/node_exporter.service

Paste the following into the file. Exit and save.

[Unit]
Description=Node Exporter
Wants=network-online.target
After=network-online.target[Service]
User=node_exporter
Group=node_exporter
Type=simple
ExecStart=/usr/local/bin/node_exporter[Install]
WantedBy=multi-user.target

Reload systemd to reflect the changes.

$ sudo systemctl daemon-reload

And then start the service with the following command and check the status to make sure it’s running correctly.

$ sudo systemctl start node_exporter
$ sudo systemctl status node_exporter

Output should look something like this.

If you did everything right, it should say active (running) in green. If not then go back and repeat the steps to fix the problem. Press Q to quit.

Finally, enable Node Exporter to start on boot.

$ sudo systemctl enable node_exporter

Test Prometheus and Node Exporter (Optional)

Everything should be ready to go. You may optionally test the functionality by opening a port in the firewall (see Step 1) and browsing to http://<yourserverip>:9090. From there you can run queries to view different metrics. For example try this query to see how much memory is free in bytes:

http://<yourserverip>:9090/new/graph?g0.expr=node_memory_MemFree_bytes&g0.tab=1&g0.stacked=0&g0.range_input=1h

Step 13 — Install Grafana

While Prometheus is our data source, Grafana is going provide our reporting dashboard capability. Let’s install it and configure a dashboard.

We will install using an APT repository because it is easier to install and update. Grafana is available in the official Ubuntu packages repository, however the version of Grafana there may not be the latest, so we will use Grafana’s official repository.

Download the Grafana GPG key with wget, then pipe the output to apt-key. This will add the key to your APT installation’s list of trusted keys.

$ wget -q -O - https://packages.grafana.com/gpg.key | sudo apt-key add -

Add the Grafana repository to the APT sources.

$ sudo add-apt-repository "deb https://packages.grafana.com/oss/deb stable main"

Refresh the apt cache.

$ sudo apt update

Make sure Grafana is installed from the repository.

$ apt-cache policy grafana

Output should look like this.

grafana:
  Installed: (none)
  Candidate: 7.1.1
  Version table:
     7.1.1 500
        500 https://packages.grafana.com/oss/deb stable/main amd64 Packages
     7.1.0 500
        500 https://packages.grafana.com/oss/deb stable/main amd64 Packages
     7.0.6 500
        500 https://packages.grafana.com/oss/deb stable/main amd6
     ...

Verify the version at the top matches the latest version shown here. Then proceed with the installation.

$ sudo apt install grafana

Start the Grafana server and heck the status to make sure it’s running correctly.

$ sudo systemctl start grafana-server
$ sudo systemctl status grafana-server

Output should look something like this.

If you did everything right, it should say active (running) in green. If not then go back and repeat the steps to fix the problem. Press Q to quit.

Enable Grafana to start on boot.

$ sudo systemctl enable grafana-server

Configure Grafana Login

Great job on getting this far! Now that you have everything up and running you can go to http://<yourserverip>:3000/ in a browser and the Grafana login screen should come up.

Enter admin for the username and password. It will prompt you to change your password and you should definitely do that.

Configure the Grafana Data Source

Let’s configure a datasource. Move your mouse over the gear icon on the left menu bar. A menu will pop-up — choose Data Sources.

Click on Add data source and then choose Prometheus. Enter http://localhost:9090 for the URL then click on Save and Test.

Import a Grafana Dashboard

Now let’s import a dashboard. Move your mouse over the + icon on the left menu bar. A menu will pop-up - choose Import.

Copy/paste the JSON from here and click Load then Import. You may need to select the data source.

You should be able to view the dashboard. At first you may not have sufficient data, but after the testnet starts and validators are activated for a while you will see some metrics and alerts.

Final Remarks

Okay… That’s it! We are done! I hope you enjoyed this guide.

• A future update includes a more comprehensive dashboard (hardware metrics and metrics on the eth1 node) and information on alerting.
• If you have feedback you can reach me on Twitter or Reddit.
• If you liked this guide and think others would benefit from it then please share it using the friends link!
• Tips: somer.eth

***
NOTE: This guide is now deprecated. Please use the newer version targeting the Pyrmont testnet.

*** located here.

Appendix — Updating Lighthouse

If you need to update the code due to changes in the Git repository follow these steps to get the latest files and build your binaries:

Check for any Rust updates.

$ rustup update

Pull latest Lighthouse code and build.

$ cd ~
$ cd lighthouse
$ git pull origin master
$ make

OR if you require a specific branch, e.g. vXYZ, use this approach. Note that rm -r lighthouse will delete the lighthouse directory.

$ cd ~ 
$ rm -r lighthouse
$ git clone -b vXYZ https://github.com/sigp/lighthouse.git
$ cd lighthouse
$ make

Next we stop the beacon chain and validator services and copy the binaries over to the /usr/local/bin directory and then start the services again.

$ cd ~
$ cd lighthouse
$ sudo systemctl stop lighthousevalidator
$ sudo systemctl stop lighthousebeacon
$ sudo cp /$HOME/.cargo/bin/lighthouse /usr/local/bin

$ sudo systemctl start lighthousebeacon
$ sudo systemctl status lighthousebeacon # <-- Check errors.
$ sudo systemctl start lighthousevalidator
$ sudo systemctl status lighthousevalidator # <-- Check errors.

That’s it, the services have been updated.