Compile Smart Contracts to Go

(instructions valid for Ubuntu)

In order to interact with a Smart Contract in a Go application, the ABI (application binary interface) of the contract must first be generated, and then compiled so that it can be imported in said application.

1. Prerequisites

1.1 Solidity compiler

Also known as solc, follow the instructions here to install it.

1.2 abigen

This is the tool used to generate the .go files with the contract ABI as input.

1.2.1 protoc tool (dependency)

Check latest stable version and replace PROTOC_ZIP accordingly.

PROTOC_ZIP=protoc-x.x.x-linux-x86_64.zip
curl -OL https://github.com/google/protobuf/releases/download/vx.x.x/$PROTOC_ZIP
sudo unzip -o $PROTOC_ZIP -d /usr/local bin/protoc
sudo unzip -o $PROTOC_ZIP -d /usr/local include/*
rm -f $PROTOC_ZIP

1.2.2 abigen tool

Install abigen by doing:

go get -u github.com/ethereum/go-ethereum
cd $GOPATH/src/github.com/ethereum/go-ethereum/
make
make devtools

1.3 ABI file

Save the Smart Contract ABI to your local drive and keep the location at hand.

If you do not have an ABI, you can generate one from the contract replacing the .sol file with your own smart contract filename:

solc --abi Contract.sol -o build

For this example, the resulting file will be ./build/Contract.abi.

2. Compilation

To convert the ABI into a Go file, execute the following command:

abigen --abi=./build/Contract.abi --pkg=mypackage --out=Contract.go

Replace the contract and package names with your own.

Example

In this fashion, the RNS Resolver was compiled by doing:

abigen --abi=MultiChainResolverABI.json --pkg=multichainresolver --out=multi_chain_resolver.go

and then imported to and used in the rns-go-lib project.

Guide based on Smart Contract Compilation & ABI by Miguel Mota.