Rust区块链共识插件pallet-grandpa的使用：Substrate框架下权威证明（PoA）的GRANDPA最终性工具

概述

GRANDPA是Substrate框架中的最终性共识模块，专为运行时环境设计。它管理着GRANDPA权威集合的准备工作，这些权威仅用于GRANDPA最终性确认，而非整体共识机制。

未来，该模块还将处理不当行为报告和链上最终性通知。

安装

在项目目录中运行以下Cargo命令：

cargo add pallet-grandpa

或在Cargo.toml中添加：

pallet-grandpa = "42.0.0"

核心功能

• 管理GRANDPA权威集合
• 为原生代码准备最终性小工具
• 未来将支持不当行为报告和链上最终性通知

完整集成

要与GRANDPA完全集成，需要实现GrandpaApi。必要的项可通过fg_primitives crate重新导出。

示例代码

以下是Substrate链中使用pallet-grandpa的基本配置示例：

// runtime/src/lib.rs

// 1. 引入必要的依赖
use frame_support::traits::{GenesisBuild, OnFinalize, OnInitialize};
use sp_consensus_grandpa::AuthorityId;

// 2. 配置pallet-grandpa
impl pallet_grandpa::Config for Runtime {
    type Event = Event;
    type Call = Call;
    type KeyOwnerProofSystem = ();
    type KeyOwnerProof = <Self::KeyOwnerProofSystem as KeyOwnerProofSystem<(
        KeyTypeId,
        AuthorityId,
    )>>::Proof;
    type KeyOwnerIdentification = <Self::KeyOwnerProofSystem as KeyOwnerProofSystem<(
        KeyTypeId,
        AuthorityId,
    )>>::IdentificationTuple;
    type HandleEquivocation = ();
    type WeightInfo = ();
}

// 3. 在construct_runtime!宏中包含pallet-grandpa
construct_runtime!(
    pub enum Runtime where
        Block = Block,
        NodeBlock = opaque::Block,
        UncheckedExtrinsic = UncheckedExtrinsic
    {
        // ... 其他pallet
        Grandpa: pallet_grandpa::{Module, Call, Storage, Config, Event},
    }
);

// 4. 实现GRANDPA API
sp_api::impl_runtime_apis! {
    impl sp_consensus_grandpa::GrandpaApi<Block> for Runtime {
        fn grandpa_authorities() -> Vec<(AuthorityId, u64)> {
            Grandpa::grandpa_authorities()
        }
        // ... 其他必要的方法实现
    }
}

// 5. 创世配置示例
pub struct GenesisConfig {
    pub grandpa: pallet_grandpa::GenesisConfig,
}

impl genesis::GenesisConfig for GenesisConfig {
    fn genesis_state(&self) -> Vec<u8> {
        let mut storage = vec![];
        pallet_grandpa::GenesisConfig::assimilate_storage(&self.grandpa, &mut storage)
            .expect("Failed to assimilate storage for Grandpa pallet");
        storage
    }
}

完整示例demo

以下是一个完整的pallet-grandpa集成示例，包含运行时配置和创世设置：

// runtime/src/lib.rs

use frame_support::{
    construct_runtime, parameter_types,
    traits::{GenesisBuild, KeyOwnerProofSystem, OnFinalize, OnInitialize},
    weights::Weight,
};
use sp_consensus_grandpa::AuthorityId as GrandpaId;
use sp_runtime::{
    generic,
    traits::{BlakeTwo256, IdentifyAccount, Verify},
    MultiSignature, RuntimeDebug,
};

// 1. 定义基本类型
pub type Signature = MultiSignature;
pub type AccountId = <<Signature as Verify>::Signer as IdentifyAccount>::AccountId;
pub type BlockNumber = u32;
pub type Index = u32;
pub type Balance = u128;

// 2. 定义区块类型
type Header = generic::Header<BlockNumber, BlakeTwo256>;
type Block = generic::Block<Header, UncheckedExtrinsic>;
type UncheckedExtrinsic = generic::UncheckedExtrinsic<AccountId, Call, Signature, ()>;

// 3. 配置pallet-grandpa
parameter_types! {
    pub const MaxAuthorities: u32 = 32;
}

impl pallet_grandpa::Config for Runtime {
    type Event = Event;
    type Call = Call;
    
    // 定义密钥所有者证明系统
    type KeyOwnerProofSystem = ();
    
    type KeyOwnerProof = <Self::KeyOwnerProofSystem as KeyOwnerProofSystem<(
        sp_consensus_grandpa::KEY_TYPE,
        GrandpaId,
    )>>::Proof;
    
    type KeyOwnerIdentification = <Self::KeyOwnerProofSystem as KeyOwnerProofSystem<(
        sp_consensus_grandpa::KEY_TYPE,
        GrandpaId,
    )>>::IdentificationTuple;
    
    type HandleEquivocation = ();
    type WeightInfo = ();
}

// 4. 构建运行时
construct_runtime!(
    pub enum Runtime where
        Block = Block,
        NodeBlock = Block,
        UncheckedExtrinsic = UncheckedExtrinsic
    {
        System: frame_system::{Module, Call, Config, Storage, Event<T>},
        Grandpa: pallet_grandpa::{Module, Call, Storage, Config, Event},
    }
);

// 5. 实现GRANDPA API
sp_api::impl_runtime_apis! {
    impl sp_consensus_grandpa::GrandpaApi<Block> for Runtime {
        fn grandpa_authorities() -> Vec<(GrandpaId, u64)> {
            Grandpa::grandpa_authorities()
        }
        
        fn submit_report_equivocation_unsigned_extrinsic(
            _equivocation_proof: sp_consensus_grandpa::EquivocationProof<
                <Block as sp_runtime::traits::Block>::Hash,
                sp_runtime::traits::NumberFor<Block>,
            >,
            _key_owner_proof: sp_consensus_grandpa::OpaqueKeyOwnershipProof,
        ) -> Option<()> {
            None
        }
        
        fn generate_key_ownership_proof(
            _set_id: sp_consensus_grandpa::SetId,
            _authority_id: GrandpaId,
        ) -> Option<sp_consensus_grandpa::OpaqueKeyOwnershipProof> {
            None
        }
    }
}

// 6. 创世配置
pub struct GenesisConfig {
    pub system: frame_system::GenesisConfig,
    pub grandpa: pallet_grandpa::GenesisConfig,
}

impl genesis::GenesisConfig for GenesisConfig {
    fn genesis_state(&self) -> Vec<u8> {
        let mut storage = vec![];
        
        // 初始化系统配置
        frame_system::GenesisConfig::assimilate_storage(&self.system, &mut storage)
            .expect("Failed to assimilate system storage");
            
        // 初始化GRANDPA配置
        pallet_grandpa::GenesisConfig::assimilate_storage(&self.grandpa, &mut storage)
            .expect("Failed to assimilate storage for Grandpa pallet");
            
        storage
    }
}

注意事项

• 许可证：Apache-2.0
• 该模块是Polkadot SDK的一部分
• 需要与fg_primitives crate配合使用以实现完整功能

通过正确配置和使用pallet-grandpa，开发者可以在Substrate框架中实现基于权威证明(PoA)的GRANDPA最终性共识机制。