Getting Started
Dependencies
This guide is mainly geared towards Unix users. For Windows users I recommend using Windows Subsystem for Linux to run everything.
Getting started
The Simulation Modules use Poetry to manage dependencies. To get set up with all the required dependencies, run:
pip install poetry
poetry install
To run the program you can run the command:
poetry run python -m simulations --run-id local --yaml-file ./config/configuration.yaml
This command will initially throw an error because we don't have a State Machine
ready to connect to. It is expected that the state machine is available over a
RPC-JSON connection on address 0.0.0.0 and port 8545. On a UNIX native
machine it's fairly easy to run Anvil (EVM) as follows:
anvil -f https://rpc-mainnet-ethereum.forbole.com?apikey=H4y9w5SrqhcbhpfspD4Om/vdSUsWr42XDlju8UfIZP4= --fork-block-number 16600000 --balance 99999999999 --no-storage-caching --no-mining --order fifo
Once you have this system running you can try to run the program again using the
command above. You'll see that it will now connect to the State Machine and
starts to send transactions for the Bancor project. The Bancor project is
currently the testcase that has been defined in config/configuration.yaml.
Troubleshooting
A hard part of EVMs is the troubleshooting. EVMs by default don't give much info on why a call to a contract failed, expecially when custom error objects are used to throw exceptions.
So as you can imagine it's sometimes hard to figure out what is causing an
error. There are limited options when it comes to getting more insight into the
error. One big part is to use Hardhat instead of Anvil temporarily to run as the
EVM. One caviat is that the project needs to have configuration available for
Hardhat, you can easily verify this by seeing if there's a file called
hardhat.config.ts in the main directory. Most projects use this for testing
though so there's a big chance that it's there.
The way to do this is pretty precise, you need to run Hardhat in the directory
where the contracts are stored for the project that you're running into issues
for. So for example for Bancor you would need to download the
contracts-v3 repo and run
Hardhat in the Terminal from the contracts-v3 directory.
The command to run Hardhat is
hardhat node --fork https://rpc-mainnet-ethereum.forbole.com?apikey=H4y9w5SrqhcbhpfspD4Om/vdSUsWr42XDlju8UfIZP4= --fork-block-number 16100000 --no-deploy
When you then run the simulation stack against it with the above mentioned command you should get more precise error messages. (Please note that the simulation will be significantly slower due to the Hardhat being used).
Common Errors
- Gas
Gas will be a common issue when it comes to EVM. Due to this being a simulation
we have to take gas into account, so when you run into an error related to gas
and not having enough ETH to pay for it the easiest solution is to send some ETH
from one of the 10 main accounts that automatically get generated to the address
you want to send a transaction from. There currently is a function that you can
call that will automatically give someone some ETH to pay for gas fees you can
find that function at simulations/statemachine/evm/anvil.py:61.
- Impersonate account
Impersonation is necessary to skip the authentication layer of the EVM. It is
necessary to ask the EVM to impersonate an account before you can send a
transaction from it, otherwise you will get an error. There is also the option
of automatically impersonating all accounts using the
anvil_autoImpersonateAccount RPC command. This is already included in the
project so you shouldn't have this issue, but if for some reason you run into
this issue you can see if it's still set correctly at
simulations/statemachine/evm/anvil.py:33.