nordisk/Skidbladnir

examples/render-knut-flight-k8s.rs

//! N5 — render the knut Arrow Flight server's **Kubernetes manifests** through the
//! ONE Skidbladnir renderer (`Runtime=Kube`), so the k8s deploy is Skidbladnir-driven
//! from the SAME [`crate::product::ComponentSpec`] that drives the systemd install —
//! not a hand-written YAML that can drift.
//!
//! ```sh
//! cargo run --example render-knut-flight-k8s -- dist/k8s/knut
//! # → dist/k8s/knut/knut/knut-flight-deployment.yaml + knut-flight-service.yaml
//! kubectl apply -f dist/k8s/knut/knut
//! ```
//!
//! Writes the rendered files (paths as the renderer emits them, `<ns>/<name>-*.yaml`)
//! under the given out dir (default `dist/k8s/knut`) and prints the lifecycle verbs
//! the async applier maps onto the k8s API.

use std::path::{Path, PathBuf};

use skidbladnir::layout::Layout;
use skidbladnir::product::ComponentSpec;
use skidbladnir::service::{Backend, renderer_for};

fn main() -> anyhow::Result<()> {
    let out = PathBuf::from(
        std::env::args()
            .nth(1)
            .unwrap_or_else(|| "dist/k8s/knut".to_string()),
    );

    // The Layout only matters to the systemd projection (paths); for the k8s render
    // the shape comes entirely from the ComponentSpec's k8s fields.
    let layout = Layout::dated("/var/lib/lake", "/var/log/lake", "/opt/lake");
    let spec = ComponentSpec::knut_flight().to_service_spec(&layout, Backend::Kubernetes);
    let rendered = renderer_for(Backend::Kubernetes)
        .ok_or_else(|| anyhow::anyhow!("no Kubernetes renderer"))?
        .render(&spec)?;

    for f in &rendered.files {
        let dest = out.join(&f.path);
        if let Some(parent) = dest.parent() {
            std::fs::create_dir_all(parent)?;
        }
        std::fs::write(&dest, &f.contents)?;
        set_mode(&dest, f.mode);
        println!("wrote {} (mode {:o})", dest.display(), f.mode);
    }

    println!(
        "\nlifecycle verbs (applied over the k8s API by the async driver, NOT literal kubectl):"
    );
    println!("  enable: {}", rendered.enable.join(" "));
    println!("  start : {}", rendered.start.join(" "));
    println!("  status: {}", rendered.status.join(" "));
    println!("  stop  : {}", rendered.stop.join(" "));
    Ok(())
}

#[cfg(unix)]
fn set_mode(path: &Path, mode: u32) {
    use std::os::unix::fs::PermissionsExt;
    let _ = std::fs::set_permissions(path, std::fs::Permissions::from_mode(mode));
}

#[cfg(not(unix))]
fn set_mode(_path: &Path, _mode: u32) {}