A new FRAME-based Substrate node, ready for hacking.
A fresh FRAME-based Substrate node, ready for hacking :rocket:
This project contains some configuration files to help get started :hammerandwrench:
Follow the Rust setup instructions before using the included Makefile to build the Node Template.
This project uses a Makefile to document helpful commands and make it easier to execute them. Get started by running these
maketargets:
make init- Run the init script to configure the Rust toolchain for WebAssembly compilation.
make run- Build and launch this project in development mode.
The init script and Makefile both specify the version of the Rust nightly compiler that this project depends on.
The
make runcommand will perform an initial build. Use the following command to build the node without launching it:
make build
Once the project has been built, the following command can be used to explore all parameters and subcommands:
./target/release/node-template -h
The
make runcommand will launch a temporary node and its state will be discarded after you terminate the process. After the project has been built, there are other ways to launch the node.
This command will start the single-node development chain with persistent state:
./target/release/node-template --dev
Purge the development chain's state:
./target/release/node-template purge-chain --dev
Start the development chain with detailed logging:
RUST_LOG=debug RUST_BACKTRACE=1 ./target/release/node-template -lruntime=debug --dev
If you want to see the multi-node consensus algorithm in action, refer to our Start a Private Network tutorial.
A Substrate project such as this consists of a number of components that are spread across a few directories.
A blockchain node is an application that allows users to participate in a blockchain network. Substrate-based blockchain nodes expose a number of capabilities:
libp2pnetworking stack to allow the nodes in the network to communicate with one another.
There are several files in the
nodedirectory - 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_configand
testnet_genesisfunctions, which 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 longest chain rule, the Aura block authoring mechanism and the GRANDPA finality gadget.
After the node has been built, refer to the embedded documentation to learn more about the capabilities and configuration parameters that it exposes:
./target/release/node-template --help
In Substrate, the terms "runtime" and "state transition function" are analogous - they 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 the FRAME framework 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:
impl $PALLET_NAME::Trait for Runtime.
construct_runtime!macro, which is part of the core FRAME Support library.
The runtime in this project is constructed using many FRAME pallets that ship with the core Substrate repository and a template pallet that is defined in the
palletsdirectory.
A FRAME pallet is compromised of a number of blockchain primitives:
Traitconfiguration interface is used to define the types and parameters upon which a FRAME pallet depends.
First, install Docker and Docker Compose.
Then run the following command to start a single node development chain.
./scripts/docker_run.sh
This command will firstly compile your code, and then start a local development network. You can also replace the default command (
cargo build --release && ./target/release/node-template --dev --ws-external) by appending your own. A few useful ones are as follow.
# Run Substrate node without re-compiling ./scripts/docker_run.sh ./target/release/node-template --dev --ws-externalPurge the local dev chain
./scripts/docker_run.sh ./target/release/node-template purge-chain --dev
Check whether the code is compilable
./scripts/docker_run.sh cargo check