Abigen

Compile a solidity contract into golang to deploy and call contracts programmatically.

How to Build

Download the solidity compiler from solc-bin.

Copy the appropriate compiler into your current path. ~/bin/ is a common path in most linux distributions.

# cp linux-amd64/solc-linux-amd64-v0.8.9+commit.e5eed63a ~/bin

Ensure solc can run.

# solc --version
solc, the solidity compiler commandline interface
Version: 0.8.9+commit.e5eed63a.Linux.g++

Build abigen.

# cd ~/go/src/github.com/MetalBlockchain/metalgo
# go build -o abigen cmd/abigen/main.go
# cp abigen ~/bin

Compile a contract.

# abigen --sol counter.sol --pkg main --out counter.go

This will produce counter.go suitable to interact with contract.

Example Code

Setup the connection to metalgo, then deploy, call, and fetch values from the contract.

Abigen offers more features for complicated contracts, the following is provided as an example to get started using the basic contract

package main

import (
    "context"
    "log"
    "math/big"
    "strings"
    "time"

    "github.com/MetalBlockchain/metalgo/utils/constants"
    "github.com/MetalBlockchain/metalgo/utils/formatting"
    "github.com/MetalBlockchain/coreth/accounts/abi/bind"
    "github.com/MetalBlockchain/coreth/core/types"
    "github.com/MetalBlockchain/coreth/ethclient"
    "github.com/MetalBlockchain/coreth/params"
    "github.com/MetalBlockchain/coreth/rpc"
    "github.com/decred/dcrd/dcrec/secp256k1/v3"
    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/crypto"
)

func main() {
    // setup client
    rc, err := rpc.Dial("http://localhost:9650/ext/bc/C/rpc")
    if err != nil {
        log.Fatal(err)
    }
    ec := ethclient.NewClient(rc)

    ctx := context.Background()

    // fetch networkid
    networkId, err := ec.ChainID(ctx)
    if err != nil {
        log.Fatal(err)
    }

    // parse key
    privateKeyString := "PrivateKey-ewoqjP7PxY4yr3iLTpLisriqt94hdyDFNgchSxGGztUrTXtNN"
    privateKeyBytes, err := formatting.Decode(formatting.CB58, strings.TrimPrefix(privateKeyString, constants.SecretKeyPrefix))
    if err != nil {
        log.Fatal(err)
    }
    privateKey := secp256k1.PrivKeyFromBytes(privateKeyBytes)
    privateKeyECDSA := privateKey.ToECDSA()

    // derive 'c' address
    cAddress := crypto.PubkeyToAddress(privateKeyECDSA.PublicKey)

    // setup signer and transaction options.
    signer := types.LatestSignerForChainID(networkId)
    to := &bind.TransactOpts{
        Signer: func(address common.Address, transaction *types.Transaction) (*types.Transaction, error) {
            return types.SignTx(transaction, signer, privateKeyECDSA)
        },
        From:     cAddress,
        Context:  ctx,
        GasLimit: params.ApricotPhase1GasLimit,
    }

    // deploy the contract
    storageAddress, storageTransaction, storageContract, err := DeployStorage(to, ec)
    if err != nil {
        log.Fatal(err)
    }

    // wait for the transaction to be accepted
    for {
        r, err := ec.TransactionReceipt(ctx, storageTransaction.Hash())
        if err != nil {
            if err.Error() != "not found" {
                log.Fatal(err)
            }
            time.Sleep(1 * time.Second)
            continue
        }
        if r.Status != 0 {
            break
        }
        time.Sleep(1 * time.Second)
    }

    log.Println("storageAddress", storageAddress)
    log.Println("storageTransaction", storageTransaction)

    // Call store on the contract
    storeTransaction, err := storageContract.Store(to, big.NewInt(1), common.BytesToAddress([]byte("addr1")))
    if err != nil {
        log.Fatal(err)
    }

    // wait for the transaction
    for {
        r, err := ec.TransactionReceipt(ctx, storeTransaction.Hash())
        if err != nil {
            if err.Error() != "not found" {
                log.Fatal(err)
            }
            time.Sleep(1 * time.Second)
            continue
        }
        if r.Status != 0 {
            break
        }
        time.Sleep(1 * time.Second)
    }

    log.Println("storeTransaction", storeTransaction)

    // setup call options for storage
    co := &bind.CallOpts{
        Accepted: true,
        Context:  ctx,
        From:     storageAddress,
    }

    // retrieve the value of the contract
    storageValue, err := storageContract.Retrieve(co)
    if err != nil {
        log.Fatal(err)
    }

    log.Println("storageValue", storageValue)
}