Template Rendering

What problem this solves

Template rendering turns a loaded chart and merged values into Kubernetes manifests. HelmSharp uses Helm CLI output as a compatibility oracle in tests, while application code calls the managed renderer directly.

Packages to install

dotnet add package HelmSharp.Chart --version 1.1.0
dotnet add package HelmSharp.Engine --version 1.1.0

Minimal complete code

public static async Task<string> RenderForTargetClusterAsync(
    string chartPath,
    CancellationToken cancellationToken)
{
    var chart = await HelmChartLoader.LoadAsync(chartPath, cancellationToken);
    var values = await HelmValues.BuildAsync(
        chart,
        valuesFiles: null,
        valuesContent: null,
        setValues: null,
        setFileValues: null,
        setStringValues: null,
        setJsonValues: null,
        cancellationToken: cancellationToken);

    var renderer = new HelmTemplateRenderer(
        chart,
        releaseName: "preview",
        releaseNamespace: "platform",
        values: values,
        kubeVersion: "1.30.0",
        apiVersions:
        [
            "monitoring.coreos.com/v1",
            "policy/v1"
        ],
        isUpgrade: false);

    return renderer.Render();
}

Why these APIs

HelmTemplateRenderer exposes .Release, .Chart, .Values, .Capabilities, .Files, .Template, named templates, include, tpl, and common Helm/Sprig functions to templates. kubeVersion and apiVersions let you preview output for a target cluster instead of the machine running the renderer.

Production notes

• Use explicit kubeVersion and apiVersions when previewing manifests for a known cluster.
• Render NOTES separately with RenderNotes() when the output is user-facing.
• Include CRDs through HelmClient.TemplateAsync with IncludeCRDs = true when you want command-like output.

Next step

Move to Release Workflows if you need install, upgrade, history, or rollback behavior.