🖥️Light node (Shwap)

In this guide, we install the Light node on a separate server and use data from Consensus Full Node!

Server preparation

apt update && apt upgrade -y

apt install curl build-essential git wget jq make gcc tmux htop nvme-cli pkg-config libssl-dev libleveldb-dev tar clang bsdmainutils ncdu unzip libleveldb-dev lz4 -y

Install GO

ver="1.23.1" && \
wget "https://golang.org/dl/go$ver.linux-amd64.tar.gz" && \
sudo rm -rf /usr/local/go && \
sudo tar -C /usr/local -xzf "go$ver.linux-amd64.tar.gz" && \
rm "go$ver.linux-amd64.tar.gz" && \
echo "export PATH=$PATH:/usr/local/go/bin:$HOME/go/bin" >> $HOME/.bash_profile && \
source $HOME/.bash_profile && \
go version

ufw allow 2121 comment light_node

Node installation

IMPORTANT - starting October 7th, a new version v0.18.1-mocha for the Celestia DA layer (Mocha) will be released, which will use Shwap and will not be compatible with previous versions. For the new release, it will be necessary to remove Environment=GODEBUG="asynctimerchan=1" from the service file

The process of setting up and starting a new node remains the same, but the new node will need to synchronize all blocks from the genesis, or use a snapshot synchronized with the new version. Due to optimizations, a significant decrease in hard disk usage is expected

Both protocols will work side by side during a month-long transition period from October 7th to November 7th for Mocha

cd $HOME
rm -rf celestia-node
git clone https://github.com/celestiaorg/celestia-node && cd celestia-node
git checkout tags/v0.21.9-mocha
make build
make install

celestia version
#Semantic version: v0.21.9-mocha
#Commit: f9698d454bb76f85d9110d0107016cb00684a9c7

#https://docs.celestia.org/developers/celestia-node-key/
make cel-key
mv $HOME/celestia-node/cel-key /usr/local/bin/

cel-key add light_wallet --keyring-backend test --node.type light --p2p.network mocha

# show wallet address
cel-key list --node.type light --keyring-backend test --p2p.network mocha

Initializing the light

--core.ip use the address of our remote RPC node

--p2p.network use the chain id of our network

--core.port use the gRPC port from our RPC node

--keyring.keyname use the name of the wallet we created

celestia light init \
  --core.ip <RPC_NODE_IP> \
  --p2p.network mocha \
  --core.port 9090 \
  --keyring.keyname light_wallet

Create a service file

tee <<EOF >/dev/null /etc/systemd/system/celestia-light.service
[Unit]
Description=celestia-light testnet daemon
After=network-online.target

[Service]
User=$USER
ExecStart=$(which celestia) light start \
  --p2p.network mocha \
  --metrics.tls=true --metrics --metrics.endpoint otel.mocha.celestia.observer \
  --keyring.keyname light_wallet
  
Restart=on-failure
RestartSec=3
LimitNOFILE=65535

[Install]
WantedBy=multi-user.target
EOF

systemctl daemon-reload
systemctl enable celestia-light
systemctl restart celestia-light && journalctl -u celestia-light -f -o cat

Don't forget to save the catalog with keys!!! .celestia-light-mocha-4/keys

Update

systemctl stop celestia-light

cd $HOME
rm -rf celestia-node
git clone https://github.com/celestiaorg/celestia-node && cd celestia-node
git checkout tags/v0.16.0
make build
make install
make cel-key

celestia version
#Semantic version: v0.16.0
#Commit: 6744f648649ebb5fee1b27faf7aca96ecf4519b2

# update config
celestia light config-update --p2p.network mocha

systemctl restart celestia-light && journalctl -u celestia-light -f -o cat

Node transfer

For Light nodes there is no concept of double signature and if suddenly there is a need to transfer node ID to a new server, then it does not matter to us whether the old server is working or not available. The main thing is that we have a copy of two files located at /root/.celestia-light-mocha-4/keys/

Please note that we do not necessarily need to change the keyring-test wallet Let's look at the most suitable option for saving the Node ID, assuming that the old server is working:

1. Start a new server and fully sync the Light

2. Stop Light on the new server and replace the two files in /root/.celestia-light-mocha-4/keys/

3. Be sure to give the necessary rights chmod 600 /root/.celestia-light-mocha-4/keys/*

4. Restart Light on the new server and wait for full synchronization

5. Stop the old server

Useful commands

Find out Light node id

# first, let's generate an authorization token
AUTH_TOKEN=$(celestia light auth admin --p2p.network mocha)
echo $AUTH_TOKEN

# we get the peerId of our node
curl -X POST \
     -H "Authorization: Bearer $AUTH_TOKEN" \
     -H 'Content-Type: application/json' \
     -d '{"jsonrpc":"2.0","id":0,"method":"p2p.Info","params":[]}' \
     http://localhost:26658

#  another way to get Node ID
celestia p2p info --node.store ~/.celestia-light-mocha-4/

Working with wallets

# show wallet address
cel-key list --node.type light --keyring-backend test --p2p.network mocha

# check balance
celestia state balance --node.store ~/.celestia-light-mocha-4/

# restore wallet
cel-key add light_wallet --keyring-backend test --node.type light  --recover --p2p.network mocha

Status

celestia header sync-state --node.store  ~/.celestia-light-mocha-4/

Delete

systemctl stop celestia-light
systemctl disable celestia-light
rm /etc/systemd/system/celestia-light.service
systemctl daemon-reload
cd $HOME && \
rm -rf .celestia-light-mocha-4 .celestia-ap celestia-node && \
rm -rf $(which celestia)