Start Lighthouse programmatically

Cargo.toml

[package]
name = "hookable"
version = "0.1.0"
edition = "2021"

[dependencies]
eyre = "0.6.12"
tokio = { version = "1.38.0", features = ["full"] }
slog = "2.7.0"

lighthouse = { git = "https://github.com/sigp/lighthouse" }
beacon_node = { git = "https://github.com/sigp/lighthouse" }
task_executor = { git = "https://github.com/sigp/lighthouse" }
eth2 = { git = "https://github.com/sigp/lighthouse" }
environment = { git = "https://github.com/sigp/lighthouse" }
eth2_network_config = { git = "https://github.com/sigp/lighthouse" }

lighthouse.rs

use beacon_node::{ClientConfig, ProductionBeaconNode};
use environment::{
    Environment, EnvironmentBuilder, LoggerConfig, RuntimeContext,
};
use eth2::types::eth_spec::MainnetEthSpec;
use eth2_network_config::{Eth2NetworkConfig, DEFAULT_HARDCODED_NETWORK};
use eyre::eyre;
use slog::info;
use task_executor::ShutdownReason;

fn main() -> eyre::Result<()> {
    let mut environment: Environment<MainnetEthSpec> = EnvironmentBuilder::mainnet(
    )
    .initialize_logger(LoggerConfig::default())
    .map_err(|e| eyre!("{e}"))?
    .multi_threaded_tokio_runtime()
    .map_err(|e| eyre!("{e}"))?
    .eth2_network_config(
        Eth2NetworkConfig::constant(DEFAULT_HARDCODED_NETWORK)
            .map_err(|e| eyre!("{e}"))?
            .expect("failed to construct hardcoded Eth2 network configuration"),
    )
    .map_err(|e| eyre!("{e}"))?
    .build()
    .map_err(|e| eyre!("{e}"))?;
    let ctx: RuntimeContext<MainnetEthSpec> = environment.core_context();
    let log = ctx.log().clone();
    let cfg = ClientConfig::default();
    ctx.executor.clone().spawn(
        async move {
            ProductionBeaconNode::new(ctx, cfg)
                .await
                .map_err(|e| eyre!("{e}"))
                .expect("failed to start production-ready Beacon Node");
        },
        "beacon_node",
    );
    let shutdown_reason = environment
        .block_until_shutdown_requested()
        .map_err(|e| eyre!("{e}"))?;
    info!(log, "Shutting down.."; "reason" => ?shutdown_reason);

    environment.fire_signal();

    // Shutdown the environment once all tasks have completed.
    environment.shutdown_on_idle();

    match shutdown_reason {
        ShutdownReason::Success(_) => Ok(()),
        ShutdownReason::Failure(msg) => Err(msg.to_string()),
    }
    .map_err(|e| eyre!("{e}"))?;

    Ok(())
}