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/v1.3.100/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")
  -l, --logType <logType>                  Type of logging - defaults to 'table' (choices: "table", "text", "silent")
  -d, --dir <path>                         Directory path for placing the network files instead of random temp one (e.g. -d /home/user/my-zombienet)
  -f, --force                              Force override all prompt commands
  -h, --help                               display help for command

Commands:
  spawn [options] <networkConfig> [creds]  Spawn the network defined in the config
  test <testFile> [runningNetworkSpec]     Run tests on the network defined
  setup [options] <binaries...>            Setup is meant for downloading and making dev environment of ZombieNet ready
  convert <filePath>                       Convert is meant for transforming a (now deprecated) polkadot-launch configuration to zombienet configuration
  version                                  Prints zombienet version
  help [command]                           display help for command

Setting up your network config

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

Create a network config file:

touch network.toml

So in this example network 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]
chain = "rococo-local"
default_command = "/Users/bruno/Library/Caches/pop/polkadot-v1.10.0"

[[relaychain.nodes]]
name = "alice"
validator = true

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

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

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

[[parachains]]
id = 9090
default_command = "awesome-parachain"

[[parachains.collators]]
name = "pop"
command = "/Users/bruno/src/awesome-parachain/target/debug/awesome-parachain"

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

./zombienet-macos -p native spawn network.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!