coretime-renewal-bot

DISCLAIMER: This code is an example on how to handle a Core's coretime renewal using subxt and is not meant for use in production in any way. It uses Alice's dev account and a zombienet for testing purposes.

Tested against Rococo v1012000

What This Bot Does:

This bot has a few key jobs:

• Check Renewal: It looks at the Coretime Chain to see if the core you're interested in is renewable.
• Check Funds: If the core is renewable, it peeks at your account balance to make sure you have enough funds for the renewal.
• Call the Broker: If funds are good to go, it tells the broker to renew the core.
• Keep Track of Time: The bot also keeps an eye on the renewal period. It lets you know if the core was successfully renewed or not. If not, it tells you why – either the funds ran out or the renewal window slipped by.

How It Works:

The bot uses subxt to talk to the Coretime Chain. It queries for the core's renewal status and checks the account balance. If everything's a go, it tells the broker to renew the core.

The bot also manages the renewal period and updates its status accordingly. It gives you a clear read on the core's renewal status (renewed or not) and the reason for any failures.

Example Setup:

To get this bot up and running, you'll need to swap out Alice's dev account and the zombienet with your own KeyPair and RPC endpoint. Or, you can tweak the code to build the transaction and sign it offline.

Running the example

For running the example and seeing its behaviour, we use zombienet v1.3.105 with the polkadot, polkadot-execute-worker and polkadot-prepare-worker with --features fast-runtime, and polkadot-parachain, built from source (tested with v1.12.0).

We also use the subxt cli. For installing you can run:

cargo install subxt-cli

Then we need to run the following command to retrieve the metadata from the coretime rococo parachain:

subxt metadata --url https://rococo-coretime-rpc.polkadot.io -f bytes > metadata.scale

After this was setup, we need to start the zombienet with:

./zombienet-linux-x64 -p native spawn ./config/coretime-network.toml

Wait for it to be up and then open a new terminal and run:

yarn test

This will setup the cores and tasks. Once those txs are done, we can run the bot with:

cargo run <URL> <CORE_NUMBER>

Diagram

graph TD;
    Start --> Check_Arguments;
    Check_Arguments -->|Valid Arguments| Connect_Coretime_API;
    Check_Arguments -->|Invalid Arguments| Error;
    Connect_Coretime_API --> Fetch_Existential_Deposit;
    Fetch_Existential_Deposit -->|Existential Deposit Fetched| Fetch_Interlude_Length;
    Fetch_Interlude_Length -->|Interlude Length Fetched| Subscribe_to_Blockchain;
    Subscribe_to_Blockchain --> |Block Received| Check_Events;
    Check_Events -->|Core Renewable| Check_Account_Funds;
    Check_Events -->|Core Not Renewable| Subscribe_to_Blockchain;
    Check_Account_Funds -->|Enough Funds| Get_Sale_Info;
    Check_Account_Funds -->|Not Enough Funds| Warn_Add_Funds;
    Get_Sale_Info --> Check_Renewal_Period;
    Check_Renewal_Period -->|Within Renewal Window| Renew_Core;
    Check_Renewal_Period -->|Outside Renewal Window| Check_Renewal_Period_Start;
    Check_Renewal_Period_Start -->|Within Renewal Window| Warn_Add_Funds;
    Check_Renewal_Period_Start -->|Outside Renewal Window| Purchase_Core;
    Renew_Core --> Sign_Submit_Watch;
    Sign_Submit_Watch -->|Success| Renewed_Core_Message;
    Sign_Submit_Watch -->|Failed| Error_Message;
    Renew_Core -->|Failed| Error_Message;
    Renewed_Core_Message --> Subscribe_to_Blockchain;
    Error_Message --> Subscribe_to_Blockchain;
    Warn_Add_Funds --> Subscribe_to_Blockchain;
    Purchase_Core --> Subscribe_to_Blockchain;
    Subscribe_to_Blockchain --> |Block Received| Check_Events;
    Check_Events -->|No More Blocks| Stop;
    Stop --> End;
    Error --> Stop;
    Renewed_Core_Message --> Subscribe_to_Blockchain;

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