Private Zero-fee POA Geth Network

This guide to start a private POA Geth network with 2 nodes: 1 signer (to seal new blocks) and 1 rpc node (for dapp integration).

To avoid re-org issues we should use 1 signer instead of multiple signers.

The network also accepts zero-fee transactions to be mined.

Prerequisites

• Understand the basis of Geth private network, refer this docs
• Install docker engine (latest version)
• Install docker compose (latest version)
• Install nginx instance (latest version)
• Geth image: ethereum/client-go:v1.10.23

Deploy

Step 1: Prepare environment variables

Duplicate .env.rpc.example and .env.signer.example into .env.rpc and .env.signer.

Prepare .env.rpc and .env.signer with appropriate values.

For .env.signer leave the SIGNER_BOOT_NODES empty for now.

Step 2: Initialize genesis.json

Prepare genesis.json by duplicating genesis.example.json. Replace signer address in extradata section.

Make sure you initialize for both rpc node and signer node.

Then run the commands below:

bash scripts/init_node.sh .env.rpc "--gcmode=archive"
bash scripts/init_node.sh .env.signer

Step 3: Import signer account to signer node

Prepare a private_key.txt with plain-text private key of SIGNER_ADDRESS.

Also prepare a password.txt with plain-text password when you intend to secure the address once it's imported to the signer node, also fill SIGNER_PASSWORD_PATH with the absolute password.txt file path.

Then run the command:

bash scripts/import_account.sh .env.signer /<absolute-directory-path>/private_key.txt

Step 4: Start a signer node

Run the command below to start the signer node.

docker compose --env-file .env.signer -f compose/signer.docker-compose.yml up -d --force-recreate

Step 5: Set gasprice = 0 and get the node id

For some reasons, the option --miner.gasprice=0 seems not to be working with ethereum/client-go:v1.10.23. So we have to manually adjust gas price = 0 within the ipc console.

Run the command below to access signer ipc console.

bash scripts/console.sh env.signer

Then type in the console to set gas price to zero

miner.setGasPrice(0)

Then use the command below to get the node id

admin.nodeInfo

Below is the sample output

> private-poa-geth git:(master) bash scripts/console.sh .env.signer

Welcome to the Geth JavaScript console!

instance: Geth/v1.10.23-stable-67109427/linux-amd64/go1.18.4
coinbase: 0xac118f16238b5aba99f3c9dddb74d3e635136fec
at block: 935 (Wed Aug 10 2022 16:20:08 GMT+0000 (UTC))
 datadir: /root/.ethereum
 modules: admin:1.0 clique:1.0 debug:1.0 engine:1.0 eth:1.0 miner:1.0 net:1.0 personal:1.0 rpc:1.0 txpool:1.0 web3:1.0

To exit, press ctrl-d or type exit
> miner.setGasPrice(0)
true
> admin.nodeInfo
{
  enode: "enode://289688c271bbf9326d5bc1ac977ac4303bd22ef0e19de00fb7122f73b03aec71f26009029deed3e2d6653f92cb1bf197a37027834775313828e27ea217bc8a6d@10.116.0.2:30303",
  <truncated-output>
}
>

Step 6: Start the RPC node

Now you grabbed the signer node id, place it in .env.rpc at RPC_BOOT_NODES

Run the command be low to start the rpc node.

docker compose --env-file .env.rpc -f compose/rpc.docker-compose.yml up -d --force-recreate

The rpc endpoint will be live at:

• http://localhost:8545/ (http)
• http://localhost:8546/ (websocket)

Optionally you can serve those endpoints behind an nginx reverse proxy, please refer /nginx to see the configs.

Note: The RPC node is compatible with Blockscout explorer. You can host your own explorer with ease by using Blockscout.

Step 7: Start the onchain-data aggregator node (optional)

Please see ./graphql/Readme.md.

LICENSE

This repo is MIT Licensed.

Contacts

Please feel free to contact [email protected] or [email protected] if you have any inquiries.