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A fresh FRAME-based [Substrate](https://www.substrate.io/) node, ready for hacking :rocket:
Follow the steps below to get started with the Node Template, or get it up and running right from
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your browser in just a few clicks using
the [Substrate Playground](https://docs.substrate.io/playground/) :hammer_and_wrench:
### Using Nix
Install [nix](https://nixos.org/) and optionally [direnv](https://github.com/direnv/direnv) and
[lorri](https://github.com/nix-community/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
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First, complete the [basic Rust setup instructions](./docs/rust-setup.md).
Use Rust's native `cargo` command to build and launch the template node:
The `cargo run` command will perform an initial build. Use the following command to build the node
without launching it:
Once the project has been built, the following command can be used to explore all parameters and
subcommands:
```sh
./target/release/node-template -h
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 non-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_BACKTRACE=1 ./target/release/node-template -ldebug --dev
> Development chain means that the state of our chain will be in a tmp folder while the nodes are
> running. Also, **alice** account will be authority and sudo account as declared in the
> [genesis state](https://github.com/substrate-developer-hub/substrate-node-template/blob/main/node/src/chain_spec.rs#L49).
> At the same time the following accounts will be pre-funded:
> - Alice//stash
> - Bob//stash
In case of being interested in maintaining the chain' state between runs a base path must be added
so the db can be stored in the provided folder instead of a temporal one. We could use this folder
to store different chain databases, as a different folder will be created per different chain that
is ran. The following commands shows how to use a newly created folder as our db base path.
```bash
// 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/node-template --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
```
### 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.
### Multi-Node Local Testnet
If you want to see the multi-node consensus algorithm in action, refer to our
[Simulate a network tutorial](https://docs.substrate.io/tutorials/get-started/simulate-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://docs.substrate.io/main-docs/fundamentals/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://docs.substrate.io/main-docs/build/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://docs.substrate.io/reference/command-line-tools/subkey/)
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
[block finalization and forks](https://docs.substrate.io/main-docs/fundamentals/consensus/#finalization-and-forks)
and other [consensus mechanisms](https://docs.substrate.io/main-docs/fundamentals/consensus/#default-consensus-models)
such as Aura for block authoring and GRANDPA for finality.
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
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
[FRAME](https://docs.substrate.io/main-docs/fundamentals/runtime-intro/#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](https://docs.substrate.io/reference/frame-macros/) that makes it easy to
create pallets and flexibly compose them to create blockchains that can address
[a variety of needs](https://substrate.io/ecosystem/projects/).
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 [system](https://docs.substrate.io/reference/frame-pallets/#system-pallets) 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://docs.substrate.io/main-docs/build/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 and errors](https://docs.substrate.io/main-docs/build/events-errors/)
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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.
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.
./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
```