Hands-On with the Kubernetes API

Table of Contents

1. Challenge

   Navigate the Kubernetes API Structure

   • Start kubectl proxy and query the API root to confirm unauthenticated local access to the control plane.
   • Query /api and /apis to distinguish Core resources from Named API groups and identify preferred versions.
   • Retrieve the OpenAPI v3 specification for the Pod and Container schemas to identify required fields and validation constraints.
2. Challenge

   Manage Resource Lifecycle with Raw HTTP

   • Create a Pod by sending a POST request with a JSON manifest and verify its Running status with a GET request using the resource URI.
   • Apply a Strategic Merge Patch to add labels without removing existing ones, then apply a JSON Merge Patch to a Deployment to observe how it replaces entire lists and loses unspecified fields.
   • Trigger a 409 Conflict by attempting a PUT with a stale resourceVersion, then resolve it using the read-modify-write pattern with a fresh resourceVersion.
3. Challenge

   Watch Cluster State in Real Time

   • Open a persistent watch connection and create, label, and delete a Pod to capture ADDED, MODIFIED, and DELETED events in the stream.
   • Compact etcd to purge watch history, attempt to resume from an old resourceVersion to trigger a 410 Gone, and recover using the list-then-watch pattern.
   • Enable watch bookmarks to receive BOOKMARK checkpoint events, then extract the last resourceVersion to demonstrate efficient watch resumption without a full re-list.