Kubesploit

Adevinta's SRE team replaced OPA's Gatekeeper with Kyverno to mitigate memory spikes caused by data.inventory syncing in high-churn clusters.

Kyverno’s API-based dynamic context handling slashed Gatekeeper usage from 8GB to 2.7GB.

More: https://ku.bz/gNrNqqbM1

This article investigates container drift in cloud environments by examining forensic methods for detecting unauthorized changes in container images and running instances.

Learn practical approaches for drift detection, response, and incident analysis.

More: https://ku.bz/X-YSMs1DW

Security research exposes critical OPA Gatekeeper vulnerabilities: Attackers can bypass misconfigured repository policies through subdomain manipulation, enabling unauthorized container image deployments across cloud environments.

More: https://ku.bz/8hr1BhMf3

Namespace Hound is a tool that identifies and assesses potential security vulnerabilities and risks in Kubernetes clusters used by multiple tenants

More: https://ku.bz/pt-TskhHX

This week on Learn Kubernetes Weekly 133:

🧙‍♀️ A journey of writing my own Kubernetes
📊 Scaling Virtual Machines in Kubernetes Clusters: Insights for Kubernetes Applications
🕵️ Exploring the Kubernetes API Server Proxy
🥋 CVE-2024–10220: Attack and Defense
👧 Exploit me, baby, one more time: command injection in Kubernetes Log Query

Read it now: https://learnk8s.io/issues/133

⭐️ This newsletter is sponsored by Fairwinds — expert-led, fully managed Kubernetes that frees your engineers from infrastructure headaches and puts you on the fast track to production-grade success https://ku.bz/sSRQp8xDH

This article breaks down a critical RCE flaw in Kubernetes Log Query.

Attackers could inject PowerShell commands through unvalidated pattern input, leading to SYSTEM-level access on Windows nodes.

More: https://ku.bz/nN2VkHfFM

Stephan Schwarz walks through his systematic approach to performance testing Kubernetes applications.

You will learn:

- Why shared Kubernetes components skew results and how ingress controllers, service meshes, etc. create testing challenges that require careful consideration of the entire request chain
- Practical approaches to HPA configuration, including how to account for scaling latency and planning for spare capacity based on your SLA requirements
- The role of observability tools like OpenTelemetry in production environments where load testing isn't feasible, and how distributed tracing helps isolate performance bottlenecks across interdependent services

Watch (or listen to) it here: https://ku.bz/yY-FnmGfH

🌟 This episode is brought to you by Learnk8s — get started on your Kubernetes journey through comprehensive online, in-person or remote training https://learnk8s.io/training

With @Birthmarkb "Not Open Source" Farrell

Billy Thompson, Head of Global DevOps & Platform Engineering at Akamai Technologies, shares his least favourite Kubernetes feature: a recurring challenge in Cert Manager's HTTP validation when using proxy mode with load balancers.

He explains how this widespread issue impacts observability and security features in Kubernetes clusters, particularly when monitoring web traffic logs.

Watch the full interview: https://ku.bz/bh07VCK23

kapi is a lightweight proxy that sits in front of the Kubernetes API server.

It logs, inspects, and can mutate API requests and responses, supporting auditing, debugging, and workflow automation without altering the cluster control plane.

More: https://ku.bz/sjrM4Q1ch

Learn how to use Istio, a service mesh, to manage microservices in Kubernetes.

This article covers traffic control, mTLS security, and observability with Kiali, Prometheus, and Jaeger, using a Garage Management System as a practical example.

More: https://ku.bz/x4c-Bw2K1

This analysis details how Kubernetes' deprecated gitRepo volume enables root-level container escape via Git hook injection using a fake bare repo to exploit default behavior in kubelet.

More: https://ku.bz/X8KN1PdB2

Kleidi is a Kubernetes KMSv2 plugin that enables envelope encryption by offloading data key encryption to external providers like HashiCorp Vault or SoftHSM.

More: https://ku.bz/M8Xx40XfG

Master Kubernetes with Learnk8s' Advanced Kubernetes workshop!

What should you expect?

- Learn how to architect and design clusters from the ground up (in the cloud or on-prem).
- Explore the Kubernetes internal component and how the system is designed with resiliency in mind.
- Deep-dive into the networking components and observe the packets flowing into the cluster.
- Hands-on labs to test the theory with real-world scenarios!
- And more.

The next online course starts in June: https://ku.bz/bRfWBNxJc

We also run in-person courses and corporate training: https://learnk8s.io/corporate-training

The Kubernetes API server includes an HTTP proxy that allows authorized users to access pods, nodes, and external hosts from the cluster network.

With proxy and node rights, attackers can SSRF into the API server or override pod IPs to exfiltrate data.

More: https://ku.bz/r70-_Vww0

This week on Learn Kubernetes Weekly 132:

🕵️‍♂️ An In-Depth Analysis of the OpenAI's Incident and Mitigation Strategies
👩‍🔬 Taming the wild west of research computing: how policies saved us a thousand headaches
👋 We're leaving Kubernetes
📊 Resource management in Kubernetes
📉 Reducing Pod Startup Time for Java Application on EKS

Read it now: https://learnk8s.io/issues/132

⭐️ This newsletter is sponsored by Dagger — build software engineering workflows and environments https://ku.bz/GPL98fg84

push-to-K8s is as a Kubernetes controller that monitors a specified source namespace for secret changes and replicates them across all other namespaces in the cluster.

More: https://ku.bz/bxvYHJTfg

This tutorial explains how Istio Gateways control ingress and egress traffic in Kubernetes, using Gateway, VirtualService, and ServiceEntry CRDs.

More: https://ku.bz/vBV2znXq7

This tutorial builds a hardened 3-node ETCD cluster using OpenSSL with full TLS encryption (peer/client), CA management, and systemd setup.

You'll learn how to generate certs, configure secure endpoints, and verify cluster health.

More: https://ku.bz/Rh8DkWYCz

Zain Malik shares his experience managing multi-tenant Kubernetes clusters with up to 30,000 pods across clusters capped at 950 nodes.

You will learn:

- How to address challenges in large-scale Kubernetes operations, including node pool management inconsistencies and lengthy provisioning times
- Why Cluster API provides a powerful foundation for multi-cloud cluster management, and how to extend it with custom operators for production-specific needs
- How implementing GitOps principles eliminates manual intervention in critical operations like cluster upgrades

Watch (or listen to) it here: https://ku.bz/5PLksqVlk

🌟 This episode is brought to you by Learnk8s — get started on your Kubernetes journey through comprehensive online, in-person or remote training https://learnk8s.io/training

With @Birthmarkb "Big Boy" Farrell

This article shows how Kubernetes ValidatingAdmissionPolicy lets you directly enforce custom rules like immutability or uniqueness in the API server using Common Expression Language (CEL).

It eliminates the need for external webhooks or custom code.

More: https://ku.bz/F5gkJs4KC