207 lines
8.6 KiB
Markdown
207 lines
8.6 KiB
Markdown
# Substrate Node Template
|
|
|
|
[](https://playground.substrate.dev/?deploy=node-template)
|
|
|
|
A fresh FRAME-based [Substrate](https://www.substrate.io/) node, ready for hacking :rocket:
|
|
|
|
## Getting Started
|
|
|
|
Follow the steps below to get started with the Node Template, or get it up and running right from your browser
|
|
in just a few clicks using [Playground](https://playground.substrate.dev/) :hammer_and_wrench:
|
|
|
|
### Using Nix
|
|
|
|
Install [nix](https://nixos.org/) and optionally [direnv](https://github.com/direnv/direnv) and [lorri](https://github.com/target/lorri) for a fully plug
|
|
and play experience for setting up the development environment. To get all the correct dependencies activate direnv `direnv allow` and lorri `lorri shell`.
|
|
|
|
### Rust Setup
|
|
|
|
First, complete the [basic Rust setup instructions](./docs/rust-setup.md).
|
|
|
|
### Run
|
|
|
|
Use Rust's native `cargo` command to build and launch the template node:
|
|
|
|
```sh
|
|
cargo run --release -- --dev --tmp
|
|
```
|
|
|
|
### Build
|
|
|
|
The `cargo run` command will perform an initial build. Use the following command to build the node
|
|
without launching it:
|
|
|
|
```sh
|
|
cargo build --release
|
|
```
|
|
|
|
### Embedded Docs
|
|
|
|
Once the project has been built, the following command can be used to explore all parameters and
|
|
subcommands:
|
|
|
|
```sh
|
|
./target/release/node-template -h
|
|
```
|
|
|
|
## Run
|
|
|
|
The provided `cargo run` command 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.
|
|
|
|
### Single-Node Development Chain
|
|
|
|
This command will start the single-node development chain with persistent state:
|
|
|
|
```bash
|
|
./target/release/node-template --dev
|
|
```
|
|
|
|
Purge the development chain's state:
|
|
|
|
```bash
|
|
./target/release/node-template purge-chain --dev
|
|
```
|
|
|
|
Start the development chain with detailed logging:
|
|
|
|
```bash
|
|
RUST_LOG=debug RUST_BACKTRACE=1 ./target/release/node-template -lruntime=debug --dev
|
|
```
|
|
|
|
### Connect with Polkadot-JS Apps Front-end
|
|
|
|
Once the node template is running locally, you can connect it with **Polkadot-JS Apps** front-end
|
|
to interact with your chain. [Click here](https://polkadot.js.org/apps/#/explorer?rpc=ws://localhost:9944) connecting the Apps to your local node template.
|
|
|
|
Due to recent Substrate upgrade, paste the following custom types JSON in **Setting** > **Developer**
|
|
|
|
```json
|
|
{
|
|
"AccountInfo": "AccountInfoWithDualRefCount"
|
|
}
|
|
```
|
|
|
|
### Multi-Node Local Testnet
|
|
|
|
If you want to see the multi-node consensus algorithm in action, refer to
|
|
[our Start a Private Network tutorial](https://substrate.dev/docs/en/tutorials/start-a-private-network/).
|
|
|
|
## Template Structure
|
|
|
|
A Substrate project such as this consists of a number of components that are spread across a few
|
|
directories.
|
|
|
|
### 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`](https://libp2p.io/) networking stack to allow the
|
|
nodes in the network to communicate with one another.
|
|
- Consensus: Blockchains must have a way to come to
|
|
[consensus](https://substrate.dev/docs/en/knowledgebase/advanced/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](https://research.web3.foundation/en/latest/polkadot/NPoS/index.html).
|
|
- 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`](./node/src/chain_spec.rs): A
|
|
[chain specification](https://substrate.dev/docs/en/knowledgebase/integrate/chain-spec) 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, which
|
|
are used to define the genesis state for the local development chain configuration. These
|
|
functions identify some
|
|
[well-known accounts](https://substrate.dev/docs/en/knowledgebase/integrate/subkey#well-known-keys)
|
|
and use them to configure the blockchain's initial state.
|
|
- [`service.rs`](./node/src/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](https://substrate.dev/docs/en/knowledgebase/advanced/consensus#longest-chain-rule),
|
|
the [Aura](https://substrate.dev/docs/en/knowledgebase/advanced/consensus#aura) block authoring
|
|
mechanism and the
|
|
[GRANDPA](https://substrate.dev/docs/en/knowledgebase/advanced/consensus#grandpa) finality
|
|
gadget.
|
|
|
|
After the node has been [built](#build), refer to the embedded documentation to learn more about the
|
|
capabilities and configuration parameters that it exposes:
|
|
|
|
```shell
|
|
./target/release/node-template --help
|
|
```
|
|
|
|
### Runtime
|
|
|
|
In Substrate, the terms
|
|
"[runtime](https://substrate.dev/docs/en/knowledgebase/getting-started/glossary#runtime)" and
|
|
"[state transition function](https://substrate.dev/docs/en/knowledgebase/getting-started/glossary#stf-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](https://substrate.dev/docs/en/knowledgebase/runtime/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](https://substrate.dev/docs/en/knowledgebase/runtime/macros) that makes it easy to
|
|
create pallets and flexibly compose them to create blockchains that can address
|
|
[a variety of needs](https://www.substrate.io/substrate-users/).
|
|
|
|
Review the [FRAME runtime implementation](./runtime/src/lib.rs) 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!`](https://crates.parity.io/frame_support/macro.construct_runtime.html)
|
|
macro, which is part of the core
|
|
[FRAME Support](https://substrate.dev/docs/en/knowledgebase/runtime/frame#support-library)
|
|
library.
|
|
|
|
### Pallets
|
|
|
|
The runtime in this project is constructed using many FRAME pallets that ship with the
|
|
[core Substrate repository](https://github.com/paritytech/substrate/tree/master/frame) and a
|
|
template pallet that is [defined in the `pallets`](./pallets/template/src/lib.rs) directory.
|
|
|
|
A FRAME pallet is compromised of a number of blockchain primitives:
|
|
|
|
- Storage: FRAME defines a rich set of powerful
|
|
[storage abstractions](https://substrate.dev/docs/en/knowledgebase/runtime/storage) 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](https://substrate.dev/docs/en/knowledgebase/runtime/events) to
|
|
notify users of important changes in the runtime.
|
|
- Errors: When a dispatchable fails, it returns an error.
|
|
- Config: The `Config` configuration interface is used to define the types and parameters upon
|
|
which a FRAME pallet depends.
|
|
|
|
### Run in Docker
|
|
|
|
First, install [Docker](https://docs.docker.com/get-docker/) and
|
|
[Docker Compose](https://docs.docker.com/compose/install/).
|
|
|
|
Then run the following command to start a single node development chain.
|
|
|
|
```bash
|
|
./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.
|
|
|
|
```bash
|
|
# Run Substrate node without re-compiling
|
|
./scripts/docker_run.sh ./target/release/node-template --dev --ws-external
|
|
|
|
# Purge 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
|
|
```
|