Can I deploy contract with go-ethereum and sign it via MetaMask?

Question

I want to deploy contracts by using my go backend code with go-ethereum package. Since this part of the system will run as a central element (since it does a lot of other stuffs), I won't (and don't want to) access user's private keys. So, I want to deploy contracts that will be signed by users via metamask (my frontend + metamask browser extension).

According to this tutorial I could deploy my contracts, but it uses private key to sign it. Such as:

auth := bind.NewKeyedTransactor(privateKey) // Is NewClefTransactor that I should use?
auth.Nonce = big.NewInt(int64(nonce))
auth.Value = big.NewInt(0)     // in wei
auth.GasLimit = uint64(300000) // in units
auth.GasPrice = gasPrice

input := "1.0"
address, tx, instance, err := store.DeployStore(auth, client, input)
if err != nil {
    log.Fatal(err)
}

Is it possible to deploy contract by using go, but signing them via MetaMask (browser)? (As I see external signers are not supported except clef)

Clarification: Users doesn't run local nodes, the only have access to a client-side frontend that served by the go backend, but I don't want the backend to access any private keys.

Answer 1

Basically you can -

1. Pack the contract to deploy in your backend;
2. Send the payload string to the frontend;
3. MetaMask will pop to sign that data;
4. Return a packed signed transaction to backend;
5. Backend then sends this tx to geth.

Another option is that the frontend will be able to prepare the deployment payload itself, using ethers.js / web3 along with required ABI, etc. But I assume that in your case it would be easier to prepare payload on backend.