Adding a Network to Core-Geth¶

CoreGeth currently supports a handful of networks out of the box, and can readily be configured to support others.

This guide will show you how to add a network to CoreGeth.

For the context of this tutorial, I’m going to use AlphaBeta Coin as the name of my new network. - AlphaBeta Coin (ABC) will use Proof-of-Work for block issuance, namely ETHash. (Just like Ethereum.) - AlphaBeta Coin will have some arbitrary pre-mine funds allocated to a single address. - AlphaBeta Coin will have the “Istanbul” (aka “ETC’s Phoenix”) protocol upgrades and EVM features activated from genesis (the very first block (number 0)).

Define the configuration.¶

A branch docs/_tutorial-add-network is provided to illustrate the code necessary to define implement basic core-geth support for a new network.

A full diff comparing this branch against its base v1.11.22 can be seen on the Github web UI here.

Overall, the files touched include:

> git --no-pager diff --name-only v1.11.22
params/bootnodes_abc.go
params/config_abc.go
params/config_abc_test.go
params/example_abc_test.go
params/genesis_abc.go

Once the skeleton provided by docs/_tutorial-add-network is done it’s time to put the configuration into action.

We can now pursue two paths:

Use the JSON configuration to initialize a chaindata database and start our node(s), and/or
Expose the configuration as a core-geth default through geth‘s CLI flags via --abc.

This tutorial won’t cover (2) (yet).

Initialize geth’s database from the JSON configuration.¶

Build geth.

1	`> make geth`

Create a file containing the JSON encoding of ABC network’s configuration (JSON data taken from the example test above).

> cat <<EOF > abc_genesis.json
{
  "config": {
    "networkId": 4269, 
    "chainId": 4269, 
    "eip2FBlock": 0, 
    "eip7FBlock": 0, 
    "eip150Block": 0, 
    "eip155Block": 0, 
    "eip160Block": 0, 
    "eip161FBlock": 0, 
    "eip170FBlock": 0, 
    "eip100FBlock": 0, 
    "eip140FBlock": 0, 
    "eip198FBlock": 0, 
    "eip211FBlock": 0, 
    "eip212FBlock": 0, 
    "eip213FBlock": 0, 
    "eip214FBlock": 0, 
    "eip658FBlock": 0, 
    "eip145FBlock": 0, 
    "eip1014FBlock": 0, 
    "eip1052FBlock": 0, 
    "eip152FBlock": 0, 
    "eip1108FBlock": 0, 
    "eip1344FBlock": 0, 
    "eip1884FBlock": 0, 
    "eip2028FBlock": 0, 
    "eip2200FBlock": 0, 
    "disposalBlock": 0, 
    "ethash": {}, 
    "requireBlockHashes": {}
  }, 
  "nonce": "0x0", 
  "timestamp": "0x6048d57c", 
  "extraData": "0x42", 
  "gasLimit": "0x2fefd8", 
  "difficulty": "0x20000", 
  "mixHash": "0x0000000000000000000000000000000000000000000000000000000000000000", 
  "coinbase": "0x0000000000000000000000000000000000000000", 
  "alloc": {
    "366ae7da62294427c764870bd2a460d7ded29d30": {
      "balance": "0x2a"
    }
  }, 
  "number": "0x0", 
  "gasUsed": "0x0", 
  "parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000"
}
EOF

Initialize geth with this configuration (using a custom data directory).

./build/bin/geth --datadir=./abc-datadir init abc_genesis.json 
INFO [03-10|09:00:25.710] Maximum peer count                       ETH=50 LES=0 total=50
INFO [03-10|09:00:25.710] Smartcard socket not found, disabling    err="stat /run/pcscd/pcscd.comm: no such file or directory"
INFO [03-10|09:00:25.711] Set global gas cap                       cap=25000000
INFO [03-10|09:00:25.711] Allocated cache and file handles         database=/home/ia/go/src/github.com/ethereum/go-ethereum/abc-datadir/geth/chaindata cache=16.00MiB handles=16
INFO [03-10|09:00:25.728] Writing custom genesis block 
INFO [03-10|09:00:25.729] Persisted trie from memory database      nodes=1 size=139.00B time="178.942µs" gcnodes=0 gcsize=0.00B gctime=0s livenodes=1 livesize=0.00B
INFO [03-10|09:00:25.729] Wrote custom genesis block OK            config="NetworkID: 4269, ChainID: 4269 Engine: ethash EIP1014: 0 EIP1052: 0 EIP1108: 0 EIP1344: 0 EIP140: 0 EIP145: 0 EIP150: 0 EIP152: 0 EIP155: 0 EIP160: 0 EIP161abc: 0 EIP161d: 0 EIP170: 0 EIP1884: 0 EIP198: 0 EIP2028: 0 EIP211: 0 EIP212: 0 EIP213: 0 EIP214: 0 EIP2200: 0 EIP2: 0 EIP658: 0 EIP7: 0 EthashECIP1041: 0 EthashEIP100B: 0 EthashHomestead: 0 "
INFO [03-10|09:00:25.730] Successfully wrote genesis state         database=chaindata hash="5f32ce…1fe582"
INFO [03-10|09:00:25.730] Allocated cache and file handles         database=/home/ia/go/src/github.com/ethereum/go-ethereum/abc-datadir/geth/lightchaindata cache=16.00MiB handles=16
INFO [03-10|09:00:25.746] Writing custom genesis block 
INFO [03-10|09:00:25.747] Persisted trie from memory database      nodes=1 size=139.00B time="91.084µs"  gcnodes=0 gcsize=0.00B gctime=0s livenodes=1 livesize=0.00B
INFO [03-10|09:00:25.748] Wrote custom genesis block OK            config="NetworkID: 4269, ChainID: 4269 Engine: ethash EIP1014: 0 EIP1052: 0 EIP1108: 0 EIP1344: 0 EIP140: 0 EIP145: 0 EIP150: 0 EIP152: 0 EIP155: 0 EIP160: 0 EIP161abc: 0 EIP161d: 0 EIP170: 0 EIP1884: 0 EIP198: 0 EIP2028: 0 EIP211: 0 EIP212: 0 EIP213: 0 EIP214: 0 EIP2200: 0 EIP2: 0 EIP658: 0 EIP7: 0 EthashECIP1041: 0 EthashEIP100B: 0 EthashHomestead: 0 "
INFO [03-10|09:00:25.749] Successfully wrote genesis state         database=lightchaindata hash="5f32ce…1fe582"

Start geth, reusing our initialized database. 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

Adding a Network to Core-Geth¶

Define the configuration.¶

Initialize geth’s database from the JSON configuration.¶

Establish a network.¶

Set up a bootnode.¶

Start up a few nodes.¶