If you completed the checklist in Prepare a working environment, you have successfully compiled a Substrate node. This particular node—the substrate-node-template—is preconfigured with a few common modules to provide a simple working environment to get you started.
The node template includes some default blockchain essentials, like peer-to-peer networking, block authoring, consensus, and block import for finalized blocks. The node template also includes some basic functionality for working with accounts and transactions and performing administrative actions. This core set of functionality is provided through several predefined modules—called pallets—that implement specific features.
The following core modules are predefined in the node template:
pallet_balancesfor managing account assets and transfers between accounts.
pallet_transaction_paymentfor managing transaction fees for the transactions performed.
pallet_sudofor performing operations that require administrative permissions.
The node template also provides a starter
pallet_template that illustrates how to implement features in custom pallets.
A lot of what you'll be doing in this workshop is similar to what you see in the
pallet_template except that you'll implement logic that's specific to the application you're building.
To differentiate between the default Substrate node template and the workspace you'll be using to customize the node, you can rename the working directory and create a separate branch for your changes.
To prepare a custom workspace:
- Open a terminal on your local computer and navigate to the directory that contains the
substrate-node-templateroot directory by running the following command:
mv substrate-node-template workshop-node-template
In subsequent steps, the
workshop-node-templatedirectory is used to refer to the root directory for the node.
Change to the root directory for the node by running the following command:
Create a custom branch for your workspace by running a command similar to the following:
git switch -c build-substrate-workshop
Because you're only changing the name of your workspace folder and repository branch, you don't have to recompile the node. If you want to verify the build by recompiling, run the following command:
cargo build --release
After you've renamed your workspace, you can start your node in development mode and let it run in the background. In development mode, the node uses some default settings that are predefined for a development environment. A few of the default settings for the development environment include:
- Several predefined accounts, including Alice, Bob, Charlie, and Dave.
- Initial account balances for the Alice and Bob accounts.
- Root-level permissions for the Alice account.
- Predefined authority to produce and validate blocks using the Alice account.
By default, development mode also stores chain data in a temporary database and deletes that data when you stop the node.
To start the local Substrate node:
- Open a terminal shell, if needed.
- Change to the
Start the node in development mode by running the following command:
In development mode, the chain doesn't require any peer computers to finalize blocks. After some initialization messages, you should see that blocks are being proposed, sealed, and finalized. For example:
2022-10-12 13:07:18 Substrate Node 2022-10-12 13:07:18 ✌️ version 4.0.0-dev-6c701fa6109 2022-10-12 13:07:18 ❤️ by Substrate DevHub <https://github.com/substrate-developer-hub>, 2017-2022 2022-10-12 13:07:18 📋 Chain specification: Development 2022-10-12 13:07:18 🏷 Node name: cooperative-clocks-6375 2022-10-12 13:07:18 👤 Role: AUTHORITY ... 2022-10-12 13:07:24 🙌 Starting consensus session on top of parent 0x72d1778c51e4c624e39d20bd3fac5d2c800a424fbd3bde08f4863bdf90966bf9 2022-10-12 13:07:24 🎁 Prepared block for proposing at 1 (1 ms) [hash: 0xdc23986196af67f6b07a78c50cd7b42c24b2e8da2d9f8ebf81c2540c358ada06; parent_hash: 0x72d1…6bf9; extrinsics (1): [0xd047…45da]] 2022-10-12 13:07:24 🔖 Pre-sealed block for proposal at 1. Hash now 0x0e2c8238d12d4babc83881384f6f178aa2996df5083387070c3d726bb7b10aec, previously 0xdc23986196af67f6b07a78c50cd7b42c24b2e8da2d9f8ebf81c2540c358ada06. 2022-10-12 13:07:24 ✨ Imported #1 (0x0e2c…0aec)
You now have a running blockchain that's producing blocks. You can leave it running in the background or stop and restart it whenever you like.
- To stop the node, press Control-c.
- To restart the node, run
The next step is to start customizing what this blockchain does.
As you learned in Prepare a working environment, Substrate is built using the Rust programming language. So, customizing what the blockchain does means working in Rust.
If you're familiar with Rust, you can go right to Create a new pallet and start building. If you're new to Rust, you might want to review the brief introduction in Detour: Learn Rust for Substrate before you start writing code.