Teku

WARNING: Do not import your validator keys into multiple validator clients and run them at the same time, or you might get slashed. If moving validators to a new setup or different validator client, ensure deletion of the previous validator keys before continuing.

Storing your keystore password in a text file is required so that Teku can decrypt and load your validators automatically.

Create a temporary file to store your keystore password. Type your password in this file.

sudo nano $HOME/validators-password.txt

To exit and save, press Ctrl + X, then Y, then Enter.

Confirm that your keystore password is correct.

sudo cat $HOME/validators-password.txt

When specifying directories for your validator-keys, Teku expects to find identically named keystore and password files.

For example keystore-m_12221_3600_1_0_0-11222333.json and keystore-m_12221_3600_1_0_0-11222333.txt

Run the following command to create a corresponding password file for every one of your validators.

for f in $HOME/staking-deposit-cli/validator_keys/keystore*.json; do sudo cp $HOME/validators-password.txt $HOME/staking-deposit-cli/validator_keys/$(basename $f .json).txt; done

Select a tab for your Teku configuration, either Standalone Validator (Recommended) or Combined Beacon Node with Validator. Running a standalone validator configuration is recommended for best modularity and redundancy.

Standalone Validator (Recommended)

Copy your validator_keys to the data directory.

sudo mkdir -p /var/lib/teku_validator/validator_keys
sudo cp $HOME/staking-deposit-cli/validator_keys/keystore* /var/lib/teku_validator/validator_keys

Create a service user for the validator service, then create data directories and setup ownership permissions, including hardening the access to this directory.

sudo adduser --system --no-create-home --group validator
sudo chown -R validator:validator /var/lib/teku_validator
sudo chmod -R 700 /var/lib/teku_validator

Verify that your validator's keystore .json files and validator's passwords .txt files are present by checking the following directory.

sudo ls -l /var/lib/teku_validator/validator_keys

Example output of two validator's keystore.json files with matching password.txt files.

-rwx------ 1 validator validator 710 Sep 19 23:39 keystore-m_12381_3600_1_0_0-1695165818.json
-rwx------ 1 validator validator  43 Sep 19 23:39 keystore-m_12381_3600_1_0_0-1695165818.txt
-rwx------ 1 validator validator 710 Sep 19 23:39 keystore-m_12381_3600_2_0_0-1695165819.json
-rwx------ 1 validator validator  43 Sep 19 23:39 keystore-m_12381_3600_2_0_0-1695165819.txt

Create a systemd unit file to define your validator.service configuration.

sudo nano /etc/systemd/system/validator.service

Paste the following configuration into the file.

[Unit]
Description=Teku Validator Client service for Holesky
Wants=network-online.target
After=network-online.target
Documentation=https://www.coincashew.com

[Service]
Type=simple
User=validator
Group=validator
Restart=on-failure
RestartSec=3
KillSignal=SIGINT
TimeoutStopSec=900
ExecStart=/usr/local/bin/teku/bin/teku validator-client \
  --network=holesky \
  --data-path=/var/lib/teku_validator \
  --validator-keys=/var/lib/teku_validator/validator_keys:/var/lib/teku_validator/validator_keys \
  --beacon-node-api-endpoint=http://localhost:5052 \
  --validators-proposer-default-fee-recipient=<0x_CHANGE_THIS_TO_MY_ETH_FEE_RECIPIENT_ADDRESS> \
  --validators-graffiti="🏠🥩🪙🛡️" \
  --metrics-enabled=true \
  --metrics-port=8009

[Install]
WantedBy=multi-user.target

• Replace<0x_CHANGE_THIS_TO_MY_ETH_FEE_RECIPIENT_ADDRESS> with your own Ethereum address that you control. Tips are sent to this address and are immediately spendable.

• If you wish to customize a short message that is included when you produce a block, add your message to the --graffiti. Maximum length is 16 characters.

To exit and save, press Ctrl + X, then Y, then Enter.

Run the following to enable auto-start at boot time.

sudo systemctl daemon-reload
sudo systemctl enable validator

Finally, start your validator client and check it's status.

sudo systemctl start validator
sudo systemctl status validator

Check your logs to confirm that the validator clients are up and functioning.

sudo journalctl -fu validator | ccze

Combined BN+VC

Note: Teku is configured to run both validator client and beacon chain client in one process.

Setup ownership permissions, including hardening the access to this directory.

sudo chown -R consensus:consensus /var/lib/teku/
sudo chmod -R 700 /var/lib/teku/validator_keys

Copy your validator_keys to the data directory.

sudo mkdir -p /var/lib/teku/validator_keys
sudo cp $HOME/staking-deposit-cli/validator_keys/keystore* /var/lib/teku/validator_keys

Verify that your validator's keystore .json files and validator's passwords .txt files are present by checking the following directory.

sudo ls -l /var/lib/teku/validator_keys

Example output of two validator's keystore.json files with matching password.txt files.

-rwx------ 1 consensus consensus 710 Sep 19 23:39 keystore-m_12381_3600_1_0_0-1695165818.json
-rwx------ 1 consensus consensus  43 Sep 19 23:39 keystore-m_12381_3600_1_0_0-1695165818.txt
-rwx------ 1 consensus consensus 710 Sep 19 23:39 keystore-m_12381_3600_2_0_0-1695165819.json
-rwx------ 1 consensus consensus  43 Sep 19 23:39 keystore-m_12381_3600_2_0_0-1695165819.txt

Finally, restart Teku to use the new validators.

sudo systemctl restart consensus

Check your logs to confirm that the validators are up and functioning.

sudo journalctl -fu consensus | ccze

For example when using 2 validators, logs will show the following:

INFO  - Loading 2 validator keys...
INFO  - Loaded 2 Validators: 95d3986, 82b225f

Press Ctrl + C to exit the logs.

Example of Synced Teku Validator Client Logs

• Once the validator is active and proceeded through the validator activation queue, attestation messages will appear indicating successful attestations.

• Notice the key words "Validator *** Published attestation".

teku[65367]: 03:50:51.761 INFO  - Validator cc1f3ade status is active_ongoing.
teku[65367]: 03:50:52.203 INFO  - Validator   *** Published attestation        Count: 1, Slot: 31362, Root: 90FC0DF4D5958E469134A015203B53B3FB94A0FC1038FB2462882906D4A729A2

Delete the temporary keystore password file.

sudo rm $HOME/validators-password.txt

Cleanup leftover validator_keys

Verify that you have backups of validator_keys directory. The contents are the keystore files.

Having backup copies of your validator_keys directory on USB media can make recovery from node problems quicker. Validator keys can always be regenerated from secret recovery mnemonic phrase.

You may safely delete the directory.

# Remove default validator_key directory
sudo rm -r $HOME/staking-deposit-cli/validator_keys