Truffle. How to link deployed library by address during migration?

Question

For now I use this code to link library during truffle migration:

deployer.deploy(SafeMathLibExt);
deployer.link(SafeMathLibExt, [CrowdsaleTokenExt]);
deployer.deploy(CrowdsaleTokenExt);

This code deploys library each time and I don't like it. I want to deploy library only once and then always use it. So I want something like that (pseudo code):

const library = deployer.getLibrary(libraryAddress);
deployer.link(library, [CrowdsaleTokenExt]);
deployer.deploy(CrowdsaleTokenExt);

is it possible to achieve in truffle?

Answer 1

Well you would have to go outside truffle and deploy the script manually. By doing that the library contract would be outside the purview of truffle, so whenever you do truffle migrate, only the token contract is deployed again.

So it would work something like this:

var web3 = require("web3");
var fs = require("fs");
var solc = require("solc");

web3 = new web3(new web3.providers.HttpProvider("http://localhost:8545"));

var compiledCode = 

solc.compile(fs.readFileSync('./contracts/SafeMathLibExt.sol', 'utf8'),1);

var source = compiledCode.contracts[":SafeMathLibExt"];

var tokencontract = new  web3.eth.Contract(JSON.parse(source.interface));

tokencontract.deploy({data: source.bytecode}).send({from: Owneraddress, 
gas:1500000}).on('confirmation', function(confirmationNumber, receipt){ 
console.log(confirmationNumber); tokencontract.options.address = 
receipt.contractAddress; }).on('receipt', function(receipt)
{console.log(receipt)})