Node emulator mode

For description of how this mode operates see a short introduction on the Variants of use page.

Getting CLB executable

The executable cardano-node-socket-emulator to run CLB is a separate cabal project located in the project repository under emulator (opens in a new tab) folder.

Currently, no binary distribution is available so you have to include it into your project using Nix or build it separately.

Spinning up CLB instance

Almost like with a real cardano-node you have to provide a lot of things to the binary to spin up an instance of emualator which is effectively a degenerated network that consists of one only node which is in change of producing blokcs.

Whereas you can prepare all things manually, the recommended way is to use cardano-testnet (opens in a new tab) from cardano-node (opens in a new tab) repository.

This tool is capable of generating network genesis and configuration based on your preferences and running any executable that can understand it by utilising CARDANO_NODE environment variable.

That way having cardano-testnet executable at hand you can do this (pay attention that currently only text logging is supported):

$ export CARDANO_NODE=/path/to/cardano-node-socket-emulator
$ cardano-testnet \
    cardano
    --conway-era
    --testnet-magic 764824073
    --nodeLoggingFormat text

Under the hood cardano-testnet generates a temporary folder which contains:

• configuration, topology and genesis files
• signing keys of genesis wallets
• IPC socket for the nodes
• logs

Then it runs the binary set in CARDANO_NODE with the following set of parameters (listed here for informational purposes):

$ cardano-node-socket-emulator run \
    --config /tmp/configuration.yaml
    --topology /tmp/pools-keys/pool2/topology.json
    --database-path /tmp/pools-keys/pool2/db
    --shelley-kes-key /tmp/pools-keys/pool2/kes.skey
    --shelley-vrf-key /tmp/pools-keys/pool2/vrf.skey
    --byron-delegation-certificate /tmp/pools-keys/pool2/byron-delegation.cert
    --byron-signing-key /tmp/pools-keys/pool2/byron-delegate.key
    --shelley-operational-certificate /tmp/pools-keys/pool2/opcert.cert
    --socket-path /tmp/socket/pool2/sock
    --host-addr 127.0. 0.1
    --port 43159

Example: CLB as backend for privnet tests in CTL

As a reference example you can use the way CLB is integrated with cardano-transaction-lib (opens in a new tab) as it's done in this PR (opens in a new tab).