Aave V2 Migration

[micahalcorn]

It's getting time to migrate to AAVE v2. Interest rates are higher, liquidity is bigger and gas cost is supposed to be cheaper.

The API has changed in AAVE v2, so we will need to deploy a new strategy contract.

API changes

Our current AAVE strategy code. New v2 AAVE lending pool code.

Deposit method has changed from

deposit(address _reserve, uint256 _amount, uint16 _referralCode)

to:

deposit(
    address asset,
    uint256 amount,
    address onBehalfOf,
    uint16 referralCode
  )

Withdraw method has changed be on the pool contract instead of on the aToken:

I think the method signature remains the same, but we should check that we match the new:

withdraw(
    address asset,
    uint256 amount,
    address to
  )

Balance checking remains the same, just using the new atoken.

We'll need to add the ability to set the platformAddress storage slot in the AaveStrategy. Unless I'm missing something obvious, I don't see a setter. Alternately, we could just hardcode it in the new contract.

Governance Proposal

We'll need a governance proposal to:

1. Pull funds out from strategy - VaultAdmin.withdrawAllFromStrategy(0x9f2b18751376cF6a3432eb158Ba5F9b1AbD2F7ce)
2. Upgrade strategy
3. Set atoken AAVEStrategy.setPTokenAddress(0x6b175474e89094c44da98b954eedeac495271d0f, 0x028171bca77440897b824ca71d1c56cac55b68a3 )
4. Set platform
   AAVEStrategy.setPlatformToken(0x7d2768de32b0b80b7a3454c06bdac94a69ddc7a9)
5. Reallocate Funds - VaultCore.allocate()

Token cheatsheet

V	Name	Address
v1	aDAI	0xfC1E690f61EFd961294b3e1Ce3313fBD8aa4f85d
v2	aDAI	0x028171bca77440897b824ca71d1c56cac55b68a3
v1	LendingPool	0x398ec7346dcd622edc5ae82352f02be94c62d119
v2	LendingPool	0xd97fE382b923F75Ab8951915eCF07CBf12c102D4
v1	LendingPoolProvider	0x24a42fd28c976a61df5d00d0599c34c4f90748c8
v2	LendingPoolProvider	0x7d2768de32b0b80b7a3454c06bdac94a69ddc7a9

To Do

• Update contract
• Update mocks
• Write deploy script
• Test on fork
• Deploy contract
• Test on fork
• Governance Actions

[DanielVF]

AAVE v1 to Compound, intermediate migration

We've decided we want to go ahead and move the funds out of AAVE v1 until we code support for AAVE v2. We'll need a governance action to set the cToken for DAI for the Compound Strategy, followed by three strategist actions.

@tomlinton Do you want to have a look over these? If they look good, do you want connect with @franckc, and decide who will create the governance proposal?

Here's my internal test script for checking the procedure.

0. Setup additional contracts for this sim

from world import *
from addresses import *
AAVE_STRAT = "0x9f2b18751376cF6a3432eb158Ba5F9b1AbD2F7ce"
COMP_STRAT = "0xD5433168Ed0B1F7714819646606DB509D9d8EC1f"
CDAI = "0x5d3a536e4d6dbd6114cc1ead35777bab948e3643"
GOV = "0x8e7bDFeCd1164C46ad51b58e49A611F954D23377"
aave_strat = Contract.from_explorer(AAVE_STRAT)
comp_strat = Contract.from_explorer(COMP_STRAT)

1. Governance action

comp_strat.setPTokenAddress(DAI, CDAI, {'from':GOV})  # Gas used: 48624

2. Strategist actions

vault_admin.setAssetDefaultStrategy(DAI, COMP_STRAT ,{'from':STRATEGIST}) # Gas 40,557
vault_admin.withdrawAllFromStrategy(AAVE_STRAT, {'from':STRATEGIST}) # Gas used: 596,289
vault_core.allocate({'from':STRATEGIST}) # Gas used: 1,519,170

3. Testing that it worked

# Vault totals correct
>>> int(vault_core.checkBalance(DAI) / 1e18)
1,743,564
>>> int(vault_core.checkBalance(USDC) / 1e6)
5,125,727
>>> int(vault_core.checkBalance(USDT) / 1e6)
11,315,454

# No DAI in AAVE
>>> int(aave_strat.checkBalance(DAI) / 1e18)
0
# DAI moved to compound
>>> int(comp_strat.checkBalance(DAI) / 1e18)
1,564,762

# Mints and Redeems stil work
dai.approve(vault_core, 1e18 * 1e18, {'from': COLDWALLET}) # Gas: 29,106
vault_core.mint(DAI, 1e6 * 1e18, 0, {'from': COLDWALLET}) #Gas: 2,176,467
vault_core.redeem(int(0.95 * 1e6 * 1e18), 0, {'from': COLDWALLET}) # Gas: 2,094,212


>>> int(aave_strat.checkBalance(DAI) / 1e18)
0
# DAI went into and out of Compound Strat
>>> int(comp_strat.checkBalance(DAI) / 1e18)
2420394

[DanielVF]

@mikeshultz Will we need to update analytics to look for DAI in the compound strat, or does it already do that?

[mikeshultz]

Looks like it'll need to get updated. Added an issue to track. Should be a simple update. What's the timeline on this?

OriginProtocol/ousd-analytics#136

[DanielVF]

@mikeshultz Next couple days?

[mikeshultz]

Will try and work this change in today or tomorrow.

[DanielVF]

Much awesome! Thanks!

[mikeshultz]

btw, analytics has been updated to track DAI in the Compound strategy.