Merge pull request #8 from PatrickAlphaC/master

Updated for developer experience and config for chain customization

.env

@@ -0,0 +1,3 @@
+export WEB3_INFURA_PROJECT_ID=YourProjectID
+export ETHERSCAN_TOKEN=YourApiToken
+export PRIVATE_KEY="0xasdfasdfasdfasd..."

.gitignore

@@ -3,3 +3,4 @@ __pycache__
 .hypothesis/
 build/
 reports/
+.env

README.md

@@ -14,7 +14,7 @@ This mix is configured for use with [Ganache](https://github.com/trufflesuite/ga
 
 1. [Install Brownie](https://eth-brownie.readthedocs.io/en/stable/install.html) & [Ganache-CLI](https://github.com/trufflesuite/ganache-cli), if you haven't already.
 
-2. Sign up for [Infura](https://infura.io/) and generate an API key. Store it in the `WEB3_INFURA_PROJECT_ID` environment variable.
+2. Sign up for [Infura](https://infura.io/) and generate an API key. Store it in the `WEB3_INFURA_PROJECT_ID` environment variable. You can [learn more about environment variables here](https://www.twilio.com/blog/2017/01/how-to-set-environment-variables.html). If you're unfamiliar with environment variables you can just add all these commands to your `.env` file and run `source .env` when you're done. 
 
 ```bash
 export WEB3_INFURA_PROJECT_ID=YourProjectID
@@ -32,7 +32,33 @@ export ETHERSCAN_TOKEN=YourApiToken
 brownie bake aave-flashloan
 ```
 
-## Basic Use
+5. Add your `PRIVATE_KEY` environment variable, with [a private key from you wallet.](https://metamask.zendesk.com/hc/en-us/articles/360015289632-How-to-Export-an-Account-Private-Key). *Note: If using metamask, you'll have to add a `0x` to the start of your private key) 
+
+## Quickstart (Kovan)
+
+We can see our flash loans on Etherscan via the Kovan testnet. If you're rather *run everything locally, check out the [Basic Console Use](#basic-console-use).
+
+1. Get some WETH. We need this to pay the preimum that flash loans cost. 
+
+```bash
+$ brownie run scripts/get_weth.py --network kovan
+```
+
+2. Deploy the flash loan contract. This will also fund the contract with WETH to pay the flash loan fee if it's not funded. 
+
+```bash
+$ brownie run scripts/deployment_v2.py --network kovan
+```
+
+3. Execute the flash loan 
+
+```bash
+$ brownie run scripts/run_flash_loan_v2.py --network kovan
+```
+
+This will print out an etherscan URL to see the flash loan transaction. [Like this one.](https://kovan.etherscan.io/tx/0x161d423dd1a56e7c440dabed95bea314b63668fc462567348ba4dd188e894de3)
+
+## Basic Console Use
 
 To perform a simple flash loan in a development environment:
 
@@ -85,8 +111,8 @@ Transaction sent: 0x335530e6d2b7588ee4727b35ae1ed8634a264aca04b325640101ec1c2b89
 
 [`contracts/v2/FlashloanV2.sol`](contracts/v2/FlashloanV2.sol) is where you implement your own logic for flash loans. In particular:
 
-* The size of the loan is set in line 39 in `flashloan`.
-* Custom flash loan logic is added after line 23 in `executeOperation`.
+* The size of the loan is set in line 89 in `flashloan`.
+* Custom flash loan logic is added after line 31 in `executeOperation`.
 
 See the Aave documentation on [Performing a Flash Loan](https://docs.aave.com/developers/guides/flash-loans) for more detailed information.
 
@@ -253,16 +279,13 @@ See the [Brownie documentation](https://eth-brownie.readthedocs.io/en/stable/cor
 
 When you are finished testing and ready to deploy to the mainnet:
 
-1. [Import a keystore](https://eth-brownie.readthedocs.io/en/stable/account-management.html#importing-from-a-private-key) into Brownie for the account you wish to deploy from.
-2. Edit [`scripts/deployment.py`](scripts/deployment.py) and add your keystore ID according to the comments.
-3. Run the deployment script on the mainnet using the following command:
+1. [Import a keystore](https://eth-brownie.readthedocs.io/en/stable/account-management.html#importing-from-a-private-key) into Brownie for the account you wish to deploy from. Add this as a `PRIVATE_KEY` environment variable.
+2. Run the deployment script on the mainnet using the following command:
 
 ```bash
-$ brownie run deployment --network mainnet
+$ brownie run scripts/deployment_v2.py --network mainnet
 ```
 
-You will be prompted to enter your keystore password, and then the contract will be deployed.
-
 ## Known issues
 
 ### No access to archive state errors

brownie-config.yaml

@@ -14,3 +14,17 @@ compiler:
   solc:
     remappings:
       - "@openzeppelin=OpenZeppelin/[email protected]"
+networks:
+  default: mainnet-fork
+  mainnet-fork:
+    aave_lending_pool_v2: "0xB53C1a33016B2DC2fF3653530bfF1848a515c8c5"
+    weth: "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2"
+  kovan:
+    aave_lending_pool_v2: "0x88757f2f99175387ab4c6a4b3067c77a695b0349"
+    weth: "0xd0a1e359811322d97991e03f863a0c30c2cf029c"
+  mainnet:
+    aave_lending_pool_v2: "0xB53C1a33016B2DC2fF3653530bfF1848a515c8c5"
+    weth: "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2"
+wallets:
+  from_key: ${PRIVATE_KEY}
+  from_mnemonic: ${MNEMONIC}

contracts/v2/FlashloanV2.sol

@@ -29,7 +29,7 @@ contract FlashloanV2 is FlashLoanReceiverBaseV2, Withdrawable {
         override
         returns (bool)
     {
-
+        
         //
         // This contract now has the funds requested.
         // Your logic goes here.
@@ -96,4 +96,4 @@ contract FlashloanV2 is FlashLoanReceiverBaseV2, Withdrawable {
 
         _flashloan(assets, amounts);
     }
-}
+}

interfaces/WethInterface.sol

@@ -0,0 +1,15 @@
+
+pragma solidity ^0.4.19;
+
+interface WethInterface {
+  function allowance(address owner, address spender) external view returns (uint256 remaining);
+  function approve(address spender, uint256 value) external returns (bool success);
+  function balanceOf(address owner) external view returns (uint256 balance);
+  function decimals() external view returns (uint8 decimalPlaces);
+  function name() external view returns (string memory tokenName);
+  function symbol() external view returns (string memory tokenSymbol);
+  function totalSupply() external view returns (uint256 totalTokensIssued);
+  function transfer(address to, uint256 value) external returns (bool success);
+  function transferFrom(address from, address to, uint256 value) external returns (bool success);
+  function deposit() external;
+}

scripts/deployment_v2.py

@@ -1,14 +1,19 @@
-from brownie import FlashloanV2, accounts
+from brownie import FlashloanV2, accounts, config, network
 
-AAVE_LENDING_POOL_ADDRESS_PROVIDER = "0xB53C1a33016B2DC2fF3653530bfF1848a515c8c5"
+# AAVE_LENDING_POOL_ADDRESS_PROVIDER = "0xB53C1a33016B2DC2fF3653530bfF1848a515c8c5"
 
 
 def main():
     """
     Deploy a `FlashloanV2` contract from `accounts[0]`.
     """
 
-    acct = accounts.load()  # add your keystore ID as an argument to this call
+    acct = accounts.add(
+        config["wallets"]["from_key"]
+    )  # add your keystore ID as an argument to this call
 
-    flashloan = FlashloanV2.deploy(AAVE_LENDING_POOL_ADDRESS_PROVIDER, {"from": acct})
+    flashloan = FlashloanV2.deploy(
+        config["networks"][network.show_active()]["aave_lending_pool_v2"],
+        {"from": acct},
+    )
     return flashloan

scripts/get_weth.py

@@ -0,0 +1,21 @@
+from brownie import accounts, config, network, interface
+
+
+def main():
+    """
+    Runs the get_weth function to get WETH
+    """
+    get_weth()
+
+
+def get_weth():
+    """
+    Mints WETH by depositing ETH.
+    """
+    acct = accounts.add(
+        config["wallets"]["from_key"]
+    )  # add your keystore ID as an argument to this call
+    weth = interface.WethInterface(config["networks"][network.show_active()]["weth"])
+    tx = weth.deposit({"from": acct, "value": 1000000000000000000})
+    print("Received 1 WETH")
+    return tx

scripts/run_flash_loan_v2.py

@@ -0,0 +1,22 @@
+from brownie import FlashloanV2, accounts, config, network, interface
+
+MINIMUM_FLASHLOAN_WETH_BALANCE = 500000000000000000
+ETHERSCAN_TX_URL = "https://kovan.etherscan.io/tx/{}"
+
+
+def main():
+    """
+    Executes the funcitonality of the flash loan.
+    """
+    acct = accounts.add(config["wallets"]["from_key"])
+    print("Getting Flashloan contract...")
+    flashloan = FlashloanV2[len(FlashloanV2) - 1]
+    weth = interface.WethInterface(config["networks"][network.show_active()]["weth"])
+    # We need to fund it if it doesn't have any token to fund!
+    if weth.balanceOf(flashloan) < MINIMUM_FLASHLOAN_WETH_BALANCE:
+        print("Funding Flashloan contract with WETH...")
+        weth.transfer(flashloan, "1 ether", {"from": acct})
+    print("Executing Flashloan...")
+    tx = flashloan.flashloan(weth, {"from": acct})
+    print("You did it! View your tx here: " + ETHERSCAN_TX_URL.format(tx.txid))
+    return flashloan