Truffle Migrations | Same contract deployed multiple times

Question

I'm using truffle migrations a lot, and I would like to deploy a contract twice during my migrations. Is it possible? Nowadays, I'm using migrations like

const MyContract = artifacts.require('MyContract')

module.exports = deployer => {
  deployer.deploy(MyContract)
}

Is there any way to do something like

const MyContract = artifacts.require('MyContract')

module.exports = deployer => {
  const firstDeploy = deployer.deploy(MyContract)
  const secondDeploy = deployer.deploy(MyContract)
}

And then to fetch them easily in the rest of my application?

Answer 1

I have never tried deploying two identical contracts before, alternative approach you can take, is to make a factory contract (contract that makes contracts). See EIP20 Factory

It depends how you are using the contracts, I recommend using exploring existing migration options. For example you can pass in your contract addresses into a main contract. Technically, I think you could make two contracts exactly identical under different names. Quick and Dirty.

I think you want to have main contract to track the two identical contracts.

For example your migrations file could look like

const contractMain = artifacts.require("contractMain");
const contractCopy1 = artifacts.require("contractCopy1");
const contractCopy2 = artifacts.require("contractCopy2");
module.exports = function(deployer) {

    // Don't overwrite existing contracts.
    deployer.deploy(contractCopy1, {overwrite: false})
    deployer.deploy(contractCopy2).then(function() {
        return deployer.deploy(contractMain, contractCopy1.address,contractCopy2.address);
    });

}; 

Answer 2

It is possible to deploy multiple versions of the same contract. The issue is that Truffle assumes every contract will be deployed only once.

Depending on your use case you have a couple of workarounds.

• Create different contracts that inherits from the same 'base' contract. This will work fine if you have only a few contracts to deploy.

  For example if you have a contract Token as base and you want to create a two instances one to manage games and other for assets. You can create TokenGames and TokenAssets.

• Do not use Truffle deployer, and deploy manually.

  async function initContracts(param1, param2, owner) {
    const token1 = await Token.new(param1, { from: owner });
    const token2 = await Token.new(param2, { from: owner });
    return [token1, token2];
  }
  

  A problem with this approach is that you have to manage the addresses of the contracts on your own, perhaps using a configuration file.