# Polkadot

Implementation of a https://polkadot.io node in Rust.

## To play

If you'd like to play with Polkadot, you'll need to install a client like this
one. First, get Rust (1.26.1 or later) and the support software if you don't already have it, and ensure you change the active toolchain to the stable version instead of the nightly version:

```
curl https://sh.rustup.rs -sSf | sh
sudo apt install make clang
rustup default stable
```

Then, install Polkadot PoC-1:

```
cargo install --git https://github.com/paritytech/polkadot.git --branch v0.1
```

You'll now have a `polkadot` binary installed to your `PATH`. You can drop the
`--branch v0.1` or run `cargo install --git https://github.com/paritytech/polkadot.git polkadot subkey` to get the very latest version of Polkadot, but these
instructions might not work in that case.

### Development

You can run a simple single-node development "network" on your machine by
running in a terminal:

```
polkadot --chain=dev --validator --key Alice
```

You can muck around by cloning and building the http://github.com/paritytech/polka-ui and http://github.com/paritytech/polkadot-ui or just heading to https://polkadot.js.org/apps.

### PoC-1 Testnet

You can also connect to the global PoC-1 testnet. To do this, just use:

```
polkadot --chain=poc-1
```

If you want to do anything on it (not that there's much to do), then you'll need
to get some PoC-1 testnet DOTs. Ask in the Polkadot watercooler.

## Local Two-node Testnet

If you want to see the multi-node consensus algorithm in action locally, then
you can create a local testnet. You'll need two terminals open. In one, run:

```
polkadot --chain=local --validator --key Alice -d /tmp/alice
```

and in the other, run:

```
polkadot --chain=local --validator --key Bob -d /tmp/bob --port 30334 --bootnodes 'enode://ALICE_BOOTNODE_ID_HERE@127.0.0.1:30333'
```

Ensure you replace `ALICE_BOOTNODE_ID_HERE` with the node ID from the output of
the first terminal.

## Hacking on Polkadot

If you'd actually like hack on Polkadot, you can just grab the source code and
build it. Ensure you have Rust and the support software installed:

```
curl https://sh.rustup.rs -sSf | sh
rustup update nightly
rustup target add wasm32-unknown-unknown --toolchain nightly
rustup update stable
cargo install --git https://github.com/alexcrichton/wasm-gc
cargo install --git https://github.com/pepyakin/wasm-export-table.git
sudo apt install make clang
```

Then, grab the Polkadot source code:

```
git clone https://github.com/paritytech/polkadot.git
cd polkadot
```

Then build the code:

```
./build.sh  # Builds the WebAssembly binaries
cargo build # Builds all native code
```

You can run the tests if you like:

```
cargo test --all
```

You can start a development chain with:

```
cargo run -- --chain=dev --validator --key Alice
```