/learn-solochain

Primary LanguageRustThe UnlicenseUnlicense

EVM compatible Solochain

Base on Frontier

Getting Started

Supported OS:

  • Linux
  • MacOS
  • WSL2 on Windows

Install Rust:

Install Nix:

curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | sh -s -- install

Then enter to development environment from the root of the project folder (where flake.nix exist):

nix develop

Build

Use the following command to build the node without launching it:

cargo build --release

Embedded Docs

After you build the project, you can use the following command to explore its parameters and subcommands:

./target/release/solochain-template-node -h

You can generate and view the Rust Docs for this template with this command:

cargo doc --open

Single-Node Development Chain

The following command starts a single-node development chain that doesn't persist state:

./target/release/solochain-template-node --dev

To start the development chain with detailed logging, run the following command:

RUST_BACKTRACE=1 ./target/release/solochain-template-node -ldebug --dev

Development chains:

  • Maintain state in a tmp folder while the node is running.
  • Use the Alice and Bob (Bob is just in test-net, not dev-net) accounts as default validator authorities.
  • Use the Alice account as the default sudo account.
  • Are preconfigured with a genesis state (/node/src/chain_spec.rs) that includes several pre-funded development accounts.

To persist chain state between runs, specify a base path by running a command similar to the following:

// Create a folder to use as the db base path
$ mkdir my-chain-state

// Use of that folder to store the chain state
$ ./target/release/solochain-template-node --dev --base-path ./my-chain-state/

// Check the folder structure created inside the base path after running the chain
$ ls ./my-chain-state
chains
$ ls ./my-chain-state/chains/
dev
$ ls ./my-chain-state/chains/dev
db keystore network

Pre-defined accounts

Pre-founded with native token

Alice:
    pubkey:     0x1f31d7740f9b822edd0ea965f4cfcf1034c450a2
Bob:
    pubkey:     0x8347187707fea1e2418c8534998d9b8d26cd6430
AliceStash:
    pubkey:     0x81593023a7f69346a047421099a8085ed0f44f7e
BobStash:
    pubkey:     0xe1cb409bc4e2002e12875a1b0c528994fe3ef23e
unnamed1:
    pubkey:     0xAE4F6dFcdB369A6C43565b1658Ac759960a60aCb
    privkey:    0x1650222a42e77da936f8c183458814cd144e7648d683b0ab7321bd2032030c08
unnamed2:
    pubkey:     0x4dE6268744b93Ed85b4e2CF683686f4A6086293a
    privkey:    0x096e09370e3b22537c854ffc517514ad7f31639b377488a252868b4276d35826

POA authority accounts

Dev & Test net accounts:

Aura Id Grandpa Id
Alice 5GrwvaEF5zXb26Fz9rcQpDWS57CtERHpNehXCPcNoHGKutQY 5FA9nQDVg267DEd8m1ZypXLBnvN7SFxYwV7ndqSYGiN9TTpu
Bob 5FHneW46xGXgs5mUiveU4sbTyGBzmstUspZC92UhjJM694ty 5GoNkf6WdbxCFnPdAnYYQyCjAKPJgLNxXwPjwTh6DGg6gN3E

They are integrated with --alice and --bob switches for testing purpose.

Custom spec accounts: are in the auth_accounts_example.yml

Connect with Polkadot-JS Apps Front-End

After you start the node template locally, you can interact with it using the hosted version of the Polkadot/Substrate Portal front-end by connecting to the local node endpoint. A hosted version is also available on IPFS. You can also find the source code and instructions for hosting your own instance in the polkadot-js/apps repository.

Run multi-node local testnet

  • run alice node: . ./scripts/local_testnet/run_alice_node.sh
  • run bob node in another teminal: . ./scripts/local_testnet/run_bob_node.sh

Reference: Simulate a network.

Run multi-node with custom spec

  • generate keys
    • generate sr25519: . ./scripts/utils/generate_sr25519_key.sh <a password>
    • generate ed25519: . ./scripts/utils/derive_ed25519_key.sh <previous ss58 address> <previous password>
    • alternatively you can use auth_accounts_example.yml for testing purpose
  • customize customeSpec.json file
  • run . ./scripts/utils/spec_to_raw.sh to generate customSpecRaw.json
  • change ./scripts/custom_chain/node.sh according to generated keys
  • add keys to keystore by running ./scripts/custom_chain/add_keys_to_keystore.sh
  • run node
    • if it is first running node of the blockchain, run ./scripts/custom_chain/run_first_node.sh
    • otherwise run ./scripts/custom_chain/run_participant_node.sh

Reference: Multi-node with custom spec

Definitions

Node

A blockchain node is an application that allows users to participate in a blockchain network. Substrate-based blockchain nodes expose a number of capabilities:

  • Networking: Substrate nodes use the libp2p networking stack to allow the nodes in the network to communicate with one another.
  • Consensus: Blockchains must have a way to come to consensus on the state of the network. Substrate makes it possible to supply custom consensus engines and also ships with several consensus mechanisms that have been built on top of Web3 Foundation research.
  • RPC Server: A remote procedure call (RPC) server is used to interact with Substrate nodes.

There are several files in the node directory. Take special note of the following:

  • chain_spec.rs: A chain specification is a source code file that defines a Substrate chain's initial (genesis) state. Chain specifications are useful for development and testing, and critical when architecting the launch of a production chain. Take note of the development_config and testnet_genesis functions. These functions are used to define the genesis state for the local development chain configuration. These functions identify some well-known accounts and use them to configure the blockchain's initial state.
  • service.rs: This file defines the node implementation. Take note of the libraries that this file imports and the names of the functions it invokes. In particular, there are references to consensus-related topics, such as the block finalization and forks and other consensus mechanisms such as Aura for block authoring and GRANDPA for finality.

Runtime

In Substrate, the terms "runtime" and "state transition function" are analogous. Both terms refer to the core logic of the blockchain that is responsible for validating blocks and executing the state changes they define. The Substrate project in this repository uses FRAME to construct a blockchain runtime. FRAME allows runtime developers to declare domain-specific logic in modules called "pallets". At the heart of FRAME is a helpful macro language that makes it easy to create pallets and flexibly compose them to create blockchains that can address a variety of needs.

Review the FRAME runtime implementation included in this template and note the following:

  • This file configures several pallets to include in the runtime. Each pallet configuration is defined by a code block that begins with impl $PALLET_NAME::Config for Runtime.
  • The pallets are composed into a single runtime by way of the construct_runtime! macro, which is part of the core FRAME pallet library.

Pallets

The runtime in this project is constructed using many FRAME pallets that ship with the Substrate repository and a template pallet that is defined in the pallets directory.

A FRAME pallet is comprised of a number of blockchain primitives, including:

  • Storage: FRAME defines a rich set of powerful storage abstractions that makes it easy to use Substrate's efficient key-value database to manage the evolving state of a blockchain.
  • Dispatchables: FRAME pallets define special types of functions that can be invoked (dispatched) from outside of the runtime in order to update its state.
  • Events: Substrate uses events to notify users of significant state changes.
  • Errors: When a dispatchable fails, it returns an error.

Each pallet has its own Config trait which serves as a configuration interface to generically define the types and parameters it depends on.