How do I spin up a testnet with Zombienet?

Question

Say I want to spin up a local Rococo test network with:

• Four validators
• Two parachains
• One collator per parachain

How do I do this with Zombienet?

Answer 1

You'll need to download the Zombienet executable.

You can find linux and macOS executables of the Zombienet CLI here:

• https://github.com/paritytech/zombienet/releases

Download the Zombienet CLI according to your operating system.

Tip: If you want the executable to be available system-wide then you can follow these steps (otherwise just download the executable to your working directory):

wget https://github.com/paritytech/zombienet/releases/download/v1.3.30/zombienet-macos
chmod +x zombienet-macos 
cp zombienet-macos /usr/local/bin

Make sure Zombienet CLI is installed correctly:

./zombienet-macos --help

You should see some similar output:

Usage: zombienet [options] [command]

Options:
  -c, --spawn-concurrency <concurrency>  Number of concurrent spawning process to launch, default is 1
  -p, --provider <provider>              Override provider to use (choices: "podman", "kubernetes", "native")
  -m, --monitor                          Start as monitor, do not auto cleanup network
  -h, --help                             display help for command

Commands:
  spawn <networkConfig> [creds]          Spawn the network defined in the config
  test <testFile> [runningNetworkSpec]   Run tests on the network defined
  setup <binaries...>                    Setup is meant for downloading and making dev environment of Zombienet ready
  version                                Prints zombienet version
  help [command]                         display help for command

Setting up your config

Zombienet works with a config. The config is where you specify your test network's configuration. The config is also where you can specify the Polkadot/Cumulus binaries.

Create a config file:

touch config.toml

So in this example config we are specifying that we want a Rococo Relay chain with four validators and two parachains - each with one collator. Make sure you have the compiled binaries available.

Zombienet also works with other providers such as Kubernetes and Podman.

[relaychain]
default_command = "./bin/polkadot-v0.9.37"
default_args = [ "-lparachain=debug" ]

chain = "rococo-local"
  # relaychain nodes are validators by default
  [[relaychain.nodes]]
  name = "alice"

  [[relaychain.nodes]]
  name = "bob"

  [[relaychain.nodes]]
  name = "charlie"

  [[relaychain.nodes]]
  name = "dave"

[[parachains]]
id = 1000
cumulus_based = true

  [parachains.collator]
  name = "parachain-1000-collator"
  command = "./bin/parachain-template-node-v0.9.37"

[[parachains]]
id = 1001
cumulus_based = true

  [parachains.collator]
  name = "parachain-1001-collator"
  command = "../bin/parachain-template-node-v0.9.37"

Save the file and run the Zombienet CLI using this config:

./zombienet-macos -p native spawn config.toml

You should see some nicely formatted output stating that the nodes are up and ready.

You can now interact with your nodes in polkadotJS apps!