MUL-620 - Change GSNMultisigFactory to replace the Factory pattern by a Clone Factory pattern (proxy)

[gjeanmart]

Overview

The purpose of this PR is to upgrade our GSNMultisigFactory smart-contract to use a Clone Factory pattern rather than a simple Factory pattern. Instead of deploying a new GSNMultisig contract for each creation, the Clone Factory will deploy a minimal contract only called Proxy connected to a unique contract called Master Copy (composed of the logic).

Impact

This doesn't have any impact on existing accounts.

Upgrade procedure

1. Deploy the master copy

$ npx oz create GSNMultiSigWalletWithDailyLimit --network rinkeby
Nothing to compile, all contracts are up to date.
All contracts are up to date
? Call a function to initialize the instance after creating it? Yes
? Select which function * initialize(_owners: address[], _required: uint256)
? _owners (address[]): 0x<DEPLOYER_ADDRESS>
? _required (uint256): 1
✓ Instance created at 0x77CCA5B37d17e7D94a28FC220F92A5504eefE9F4
0x77CCA5B37d17e7D94a28FC220F92A5504eefE9F4

Note the Master Copy address: 0x77CCA5B37d17e7D94a28FC220F92A5504eefE9F4

Change the owner to 0x0000000000000000000000000000000000000000 to make sure nobody can use this multisig.

$ npx oz send-tx --network rinkeby
? Pick an instance GSNMultiSigWalletWithDailyLimit at 0x77CCA5B37d17e7D94a28FC220F92A5504eefE9F4
? Select which function submitTransaction(destination: address, value: uint256, data: bytes)
? destination (address): 0x77CCA5B37d17e7D94a28FC220F92A5504eefE9F4
? value (uint256): 0
? data (bytes): 0xe20056e6000000000000000000000000<DEPLOYER_ADDRESS>0000000000000000000000000000000000000000000000000000000000000000
✓ Transaction successful. Transaction hash: 0x5d7828e38c1b24a637e02b8d0958e95faf9e60affff2116df6d6fbd2acd7b97f
Events emitted:
 - Submission(0)
 - Confirmation(0xF0f15Cedc719B5A55470877B0710d5c7816916b1, 0)
 - OwnerRemoval(0xF0f15Cedc719B5A55470877B0710d5c7816916b1)
 - OwnerAddition(0x0000000000000000000000000000000000000000)
 - Execution(0)

2. Change the code of the factory using CloneFactory

See GSNMultisigFactory.sol

3. Upgrade the Factory

$ npx oz upgrade --network rinkeby
(...)
? Which instances would you like to upgrade? Choose by name
? Pick an instance to upgrade GSNMultisigFactory
? Call a function on the instance after upgrading it? No
✓ Instance upgraded at 0xbBE9DD161ebfE7D792f4844a0C10aD7c1C3994e9. Transaction receipt: 0xbdb1f46a51b66d17036b92a8a0913fc46bd595b52dc8aefd0b0ed5de5a7b99c2
✓ Instance at 0xbBE9DD161ebfE7D792f4844a0C10aD7c1C3994e9 upgraded

4. Set the master copy

$ npx oz send-tx --network rinkeby
? Pick an instance GSNMultisigFactory at 0xbBE9DD161ebfE7D792f4844a0C10aD7c1C3994e9
? Select which function setMasterCopy(_masterCopy: address)
? _masterCopy (address): 0x77CCA5B37d17e7D94a28FC220F92A5504eefE9F4
✓ Transaction successful. Transaction hash: 0x72d12fb440fa462dfe4298c7f551dd17d59f29e9107a794c73db44d20b93de29

Testing strategy

TBD

Opened questions

• Shall we take the opportunity to upgrade the code to soliidity > 0.6.0

[teawaterwire]

not sure if create has to be payable