Google Cloud Deployment Manager can be extended to manage resources from third-party APIs by adding them as "Type Providers". The Kubernetes API is a RESTful API with an OpenAPI specification, making it a perfect candidate for a Type Provider. By creating the GKE cluster first, you can extract its API endpoint and credentials within the same deployment. You then use these outputs to dynamically configure a new Type Provider for that specific cluster's API. Finally, you use this new type to declaratively create the DaemonSet, all within a single Deployment Manager execution without needing extra services like Compute Engine.

B: Runtime Configurator is a service for storing and managing dynamic configuration data. It does not have the capability to apply configurations or create resources within a GKE cluster.

C: This approach requires an additional Compute Engine instance solely to run a kubectl command. This is inefficient and violates the principle of using the fewest possible services.

D: The Google Kubernetes Engine resource definition in Deployment Manager does not have a feature to interpret metadata entries as Kubernetes manifests to be applied to the cluster.

1. Google Cloud Documentation - Adding a Type Provider: This document explains how to extend Deployment Manager to work with third-party APIs. It states

"You can expand the types of Google Cloud resources that Deployment Manager can create by adding API-specific type providers... A type provider exposes all of the resources of a third-party API to Deployment Manager as base types that you can use in your configurations." The Kubernetes API is such a third-party API in this context.

Source: Google Cloud Documentation

"Adding a Type Provider"

Section: "Before you begin".

2. Google Cloud Documentation - Calling a Third-Party API: This guide provides a conceptual overview and explicitly mentions that the API must have an OpenAPI (formerly Swagger) specification

which the Kubernetes API does.

Source: Google Cloud Documentation

"Calling a Third-Party API"

Section: "About integrating with third-party APIs".

3. Google Cloud Community Tutorials - Automating GKE cluster and application deployment with Deployment Manager: This tutorial provides a step-by-step example of the exact process described in the correct answer. It shows creating a GKE cluster

then using its endpoint to create a Type Provider

and finally using that provider to deploy a Kubernetes application.

Source: Google Cloud Community Tutorials

"Automating GKE cluster and application deployment with Deployment Manager"

Sections: "Creating the Deployment Manager configuration" and "Creating the Kubernetes type provider".