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CLI

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it is not possible to run an execution client on its own anymore. After The Merge, both execution and consensus clients must be run together in order for a user to gain access to the Ethereum network.

Table of content​

You can either run your own ethereum layers (node) or use free providers.

Online Providers​

getblock.io​

geth attach https://eth.getblock.io/token/mainnet/

Infura​

curl -X POST \
-H "Content-Type: application/json" \
--data '{"jsonrpc": "2.0", "id": 1, "method": "eth_blockNumber", "params": []}' \
"https://sepolia.infura.io/v3/api-key"

Testnet Node​

Geth, Clef, Consensus client​

Geth is Official implementation of the Ethereum execution layer in Go

Geth is a command-line interface for the Ethereum blockchain. Geth is an Ethereum client written in Go. This means running Geth turns a computer into an Ethereum node. Ethereum is a peer-to-peer network where information is shared directly between nodes rather than being managed by a central server. Every 12 seconds one node is randomly selected to generate a new block containing a list of transactions that nodes receiving the block should execute. This block proposer node sends the new block to its peers. On receiving a new block, each node checks that it is valid and adds it to their database. The sequence of discrete blocks is called a blockchain. The information provided in each block is used by Geth to update its state.
Clef is an account management tool external to Geth itself that allows users to sign transactions.
Geth also needs to be connected to a Consensus client in order to function as an Ethereum node.

Clef

Sync modes​

  • Snap (default): Snap sync starts from a relatively recent block and syncs from there to the head of the chain,.
  • Full: An archive node is a node that retains all historical data right back to genesis
  • Light: A light node syncs very quickly and stores the bare minimum of blockchain data

Light nodes are not currently working on proof-of-stake Ethereum

Installation & Requirements​

These commands will intall geth, clef, devp2p, abigen, bootnode, evm, rlpdump and puppeth

# Ubuntu
sudo apt-get install -y software-properties-common
sudo add-apt-repository -y ppa:ethereum/ethereum
sudo apt-get update
sudo apt-get install ethereum

# Arch
sudo pacman -Syyuu geth nodejs
pamac install lighthouse-ethereum-bin

An accurate clock is required to participate in the Ethereum network

sudo ntpdate -s time.nist.gov

Make sure you have the following ports open

sudo iptables -I INPUT -p tcp --dport 30311 -j ACCEPT
sudo iptables -I INPUT -p udp --dport 30311 -j ACCEPT
sudo iptables -I INPUT -p tcp --dport 30303 -j ACCEPT
sudo iptables -I INPUT -p udp --dport 30303 -j ACCEPT
sudo iptables -I INPUT -p tcp --dport 30304 -j ACCEPT
sudo iptables -I INPUT -p udp --dport 30304 -j ACCEPT
sudo iptables -I INPUT -p tcp --dport 37608 -j ACCEPT
sudo iptables -I INPUT -p udp --dport 37608 -j ACCEPT
sudo iptables -I INPUT -p tcp --dport 8546 -j ACCEPT
sudo iptables -I INPUT -p udp --dport 8546 -j ACCEPT
sudo iptables -I INPUT -p tcp --dport 8551 -j ACCEPT
sudo iptables -I INPUT -p udp --dport 8551 -j ACCEPT
sudo iptables -I INPUT -p tcp --dport 8545 -j ACCEPT
sudo iptables -I INPUT -p udp --dport 8545 -j ACCEPT
sudo iptables -I INPUT -p tcp --dport 3334 -j ACCEPT
sudo iptables -I INPUT -p udp --dport 3334 -j ACCEPT
sudo iptables -I INPUT -p tcp --dport 9000 -j ACCEPT
sudo iptables -I INPUT -p udp --dport 9000 -j ACCEPT
sudo iptables -I INPUT -p tcp --dport 9001 -j ACCEPT
sudo iptables -I INPUT -p udp --dport 9001 -j ACCEPT
sudo iptables -I INPUT -p tcp --dport 5052 -j ACCEPT
sudo iptables -I INPUT -p udp --dport 5052 -j ACCEPT
sudo iptables -I INPUT 1 -i lo -j ACCEPT
sudo iptables -A INPUT -i ens3 -p udp -m multiport --dports 1900,5351,5353 -j ACCEPT
sudo iptables -A INPUT -i ens3 -p tcp -m multiport --dports 49152 -j ACCEPT

Clef​

Clef is the Accounts Management and has the responsibility of generating and storing keys, and signing transactions.

Create a new account with Clef:

mkdir enode
clef newaccount --keystore enode/keystore

To start Clef, run the Clef executable passing as arguments the keystore file location, config directory location and a chain ID. The config directory was automatically created inside the geth-tutorial directory during the previous step. The chain ID is an integer that defines which Ethereum network to connect to. Ethereum mainnet has chain ID 1. In this tutorial Chain ID 11155111 is used which is that of the Sepolia testnet

clef --keystore enode/keystore --configdir enode/clef --chainid 11155111

Geth​

Geth is responsible for running the Ethereum node. Communicating with the network, sending and validating transactions, and interacting with Smart Contracts. Geth also keep the state of the blockchain.

By default, Geth uses snap-sync which download blocks sequentially from a relatively recent block, not the genesis block.
Your ISP must also allow UDP and TCP traffics to pass through.

geth --sepolia --datadir enode --authrpc.addr 0.0.0.0 --authrpc.port 8551 --authrpc.vhosts "*" --authrpc.jwtsecret enode/jwtsecret --http --http.api eth,net,admin --signer enode/clef/clef.ipc --verbosity 5 --maxpeers 100 --allow-insecure-unlock --discv5 --bootnodes "enode://ec66ddcf1a974950bd4c782789a7e04f8aa7110a72569b6e65fcd51e937e74eed303b1ea734e4d19cfaec9fbff9b6ee65bf31dcb50ba79acce9dd63a6aca61c7@52.14.151.177:30303","enode://9246d00bc8fd1742e5ad2428b80fc4dc45d786283e05ef6edbd9002cbc335d40998444732fbe921cb88e1d2c73d1b1de53bae6a2237996e9bfe14f871baf7066@18.168.182.86:30303"
# --nat=none --maxpendpeers 10 --nodiscover

Get some Sepolia ETH from https://www.infura.io/faucet/sepolia.
Connet to your geth node

geth attach http://127.0.0.1:8545

Check if geth has connected to the network

admin.peers

To manullay add static peers to the netwrok, first find the enode address of the peer you want to connect to. for example, for sepolia you can find some here, and for mainnet you can find here

admin.addPeer("enode://ec66ddcf1a974950bd4c782789a7e04f8aa7110a72569b6e65fcd51e937e74eed303b1ea734e4d19cfaec9fbff9b6ee65bf31dcb50ba79acce9dd63a6aca61c7@52.14.151.177:30303")
admin.addPeer("enode://9246d00bc8fd1742e5ad2428b80fc4dc45d786283e05ef6edbd9002cbc335d40998444732fbe921cb88e1d2c73d1b1de53bae6a2237996e9bfe14f871baf7066@18.168.182.86:30303")

Get connected accounts

eth.accounts;

The console will hang, because Clef is waiting for approval. approve it.

Consensus clients​

Consensus client is responsible for Block Proposals, Agreement Process and Final Decision.
A Consensus client alongside geth is required to function as an Ethereum node and start syncing the blockchain.
One of the famous Consensus clients is Lighthouse. To use checkpoint syncing you need to have a Beacon Node running. There is list here.
Lighthouse needs to be publicly accessible to the network, otherwise it will not be able to sync the blockchain.
You can check it you are connected to the network by running curl http://localhost:5052/lighthouse/nat

rm -r enode/lighthouse
mkdir -p enode/lighthouse

lighthouse bn \
    --network sepolia \
    --datadir enode/lighthouse \
    --http \
    --execution-endpoint http://127.0.0.1:8551 \
    --metrics \
    --validator-monitor-auto \
    --checkpoint-sync-url https://sepolia.beaconstate.info \
    --execution-jwt enode/jwtsecret --disable-deposit-contract-sync

Testing the network​

Get latest block number:

eth.blockNumber

Useful commands​

geth account import ~/Data/myself/cryptocurrency-info-recovery/metamask/mforgood/D8_private_key

geth attach http://127.0.0.1:3334
web3.fromWei(eth.getBalance('0x7e932ab056a3dce4bcdd73092430c3f967e1bea3'), 'ether');

web3.personal.importRawKey("111111111PRIVATEKEY1111111111", "password")
personal.unlockAccount("0xD8f24D419153E5D03d614C5155f900f4B5C8A65C")
personal.listAccounts
eth.getBalance("0xD8f24D419153E5D03d614C5155f900f4B5C8A65C")
eth.getBalance(eth.accounts[1])
net.peerCount
eth.getCode("0xE683007C5BfB5BEBA5481C3e938dD4DC47cddbFC")
var voter = eth.contract([{"inputs":[{"internalType":"string","name":"option","type":"string"}],"name":"addOption","outputs":[],"name":"votes","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"}]).at("0xE683007C5BfB5BEBA5481C3e938dD4DC47cddbFC");
voter
voter.addOption("mlibre" , {from: "0xD8f24D419153E5D03d614C5155f900f4B5C8A65C"})

References​