Learn Kubernetes Weekly issue 50

It's not always DNS, Chaos-driven observability, pod as an internet egress network appliance, Kubernetes API & flow control, understanding the kubelet

25 Oct 2023

Articles

1. It's not always DNS  —  unless it is

   Tanat Paul Lokejaroenlarb

   Adevinta's team faced a months-long issue of HTTP error spikes in their clusters.

   In this case study, you'll follow their journey in identifying the issue in CoreDNS and the fixes (DNS cache, discarding invalid searches, and using FQDN as hostnames).

2. Chaos-driven observability: spotting network failures in a Kubernetes cluster

   Nikolay Sivko

   In this post, you'll simulate different network failures in a distributed system and see how they can be detected:

   1. Network partitioning.
   2. Network delay.
   3. Packet loss.

3. Experiment: Kubernetes pod as an internet egress network appliance

   Sam Gallagher

   In this article, you will explore how to forward all egress traffic to a pod connected to a VPN tunnel.

4. Kubernetes API and flow control: managing request quantity and queuing procedure

   Denys Romanenko

   This article discusses a case where the Kubernetes API became non-operational due to excessive requests.

   The team found that pods sent mass LIST requests to the API, increasing memory usage.

   By limiting simultaneous requests, they stabilized it.

5. A comprehensive understanding of kubelet

   Addo Zhang

   This article primarily delves into a source code analysis of the kubelet's functions, key components, and its booting process.

6. Connection pooling and intermittent failures in Kubernetes

   Sam Rajaei

   In this article, you'll follow the journey of troubleshooting intermittent inter-pod connection failures in EKS and learn:

   • How DNS discovery works.
   • What is conntrack.
   • How long-lived connections are handled in Kubernetes.

Articles worth checking out:

• Accessing Kubernetes services using Cloudflare Zero Trust

• Kube-bench and popeye: a power duo for AKS security compliance

• Advanced secret management on Kubernetes with Pulumi: secrets store CSI driver

• Let's learn about the otel operator's target allocator!

• My thinking about Kubebuilder

⎈ Become an expert in Kubernetes: Advanced Kubernetes course

Learnk8s

Join Learnk8s' 4-day Advanced Kubernetes workshop this November (online or in Munich, DE).

Get your hands dirty with Kubernetes and learn what makes Kubernetes tick in a session packed with hands-on labs!

Tutorials

1. Full automation with Argo rollout blue-green deployment  —  automatic rollout abort and rollback

   Piotr Kleban

   In this tutorial, you'll learn how Argo Rollouts enables automatic rollout aborts or rollbacks in case of failures and how to combine it with the Horizontal Pod Autoscaler for scaling based on metrics.

2. Verification of centralized Helm charts

   Łukasz Łopusiński

   Thanks to helm-unittest plugin, there is an accessible way of testing helm charts with any kind of chart or data configuration.

   Learn how to use it in this tutorial.

3. Managing a pool of pods dynamically inside Kubernetes

   Steve Campos

   In this 2-part tutorial, you will learn how to use the Kubernetes Javascript SDK to dynamically create preview environments made of Deployments and VirtualServices.

4. The comprehensive guide to Kubernetes volumes

   Mercy Bassey

   In this tutorial, you will explore and learn about the different types of Kubernetes volumes and their use cases, diving deep into their configuration and best practices.

5. Efficient Kubernetes cluster deployment: accelerating setup with EKS Blueprints

   Seifeddine Rajhi

   EKS Blueprints streamlines Kubernetes cluster deployment by leveraging pre-defined configurations, aiding compliance efforts.

   Learn how to use them in this tutorial.

More tutorials:

• Ingress and egress traffic in zero trust architecture with Istio service mesh on Kubernetes

Kubernetes jobs

1. • 🔥 DevOps Engineer with Exodus

   • Salary: $120K a year

   • Location: fully remote

   • Tech stack: Kubernetes, AWS, PostgreSQL, Terraform

2. • Platform Engineer with Altos Labs

   • Salary: $153K to $273.7K a year

   • Location: based in the office in San Diego, CA, USA

   • Tech stack: Kubernetes, AWS, On-premise, Docker, Shell, Python, Terraform, CDK, Ansible, Grafana

Discover more Kubernetes jobs on Kube Careers →

Code & tools

1. Kubewarden: policy engine

   Kubewarden is a policy engine for Kubernetes.

   It helps with keeping your Kubernetes clusters secure and compliant.

   Kubewarden policies can be written using regular programming or Domain Specific Languages (DSL).

2. kgoss: testing containers in Kubernetes

   kgoss is a wrapper for goss that aims to bring the simplicity of testing with goss to containers running in pods in Kubernetes.

3. Tolerable: auto-configure tolerations for architecture-based taints

   Tolerable is a Mutating Webhook, which Auto-configure tolerations for architecture-based taints.

   It patches the pod with pre-configured tolerations to schedule it on the specified architecture's node(s).

   Useful for mixed arm64/amd64 cluster nodes.

4. LVP: local volume CSI provisioner

   LVP is a CSI provisioner for provisioning simple local volumes.

   Capabilities:

   • Dynamic provisioning.
   • Create loop mounted ext4 and xfs volumes.
   • Create bind mounted volumes.
   • Resizing for ext4 and xfs volumes.

5. grafana-dashboards-kubernetes

   This repository contains a modern set of Grafana dashboards for Kubernetes.

Other interesting projects:

• kubestellar: edge, multi-cloud, and hybrid cloud

• SnapScheduler: scheduled snapshots

• AWS Reference Platform

• Cloudnativepg: PostgreSQL operator for Kubernetes

• traefik-jwt-plugin

• kubectl explore, a better kubectl explain

• Stern: tail multiple pods

• Kube-Hetzner

Upcoming Kubernetes events

1. Oct

   25

   kpt: treat your configuration as data & KCP: Kubernetes API on steroids

   In-person meetup organized by Cloud Native Budapest.

   • Location: Budapest, HU

   • This is a free event.

2. Oct

   26

   All day DevOps

   Online conference organized by Sonatype.

   • This is a virtual event

   • This event requires an entrance fee

3. Oct

   28

   Cloud Native Day Pune

   In-person conference organized by CNCG Pune Community.

   • Location: Pune, IN

   • This event requires an entrance fee

4. Oct

   30

   Observe and monitor Kubernetes clusters

   Online meetup organized by Open Operations Meetup.

   • This is a virtual event

   • This is a free event.

5. Nov

   9

   Advanced Kubernetes course

   Online workshop organized by Learnk8s.

   • This is a virtual event

   • This event requires an entrance fee

Discover more Kubernetes events on Kube Events →

Kubernetes Call for Papers

1. expired

   Kubernetes Community Days Oslo 2024

   The Call For Paper was open until 13 November 2023 at UTC. More info →

   • Location: Olso, NO

   • In-person conference organized by KCD Norway.

   • The conference starts on the 24 January 2024.

   • Apply here

2. expired

   KubeCon + CloudNativeCon Europe

   The Call For Paper was open until 26 November 2023 at UTC. More info →

   • Location: Paris, FR

   • In-person conference organized by Linux Foundation.

   • The conference starts on the 19 March 2024.

   • Apply here

3. expired

   Kubernetes Community Days Spain 2023

   The Call For Paper was open until 10 November 2023 at UTC. More info →

   • This is a virtual event

   • Online conference organized by KCD Spain.

   • The conference starts on the 12 December 2023.

   • Apply here

4. expired

   One Summit

   The Call For Paper was open until 4 December 2023 at UTC. More info →

   • Location: San Jose, CA, USA

   • In-person conference organized by Linux Foundation.

   • The conference starts on the 29 April 2024.

   • Apply here

5. expired

   DevSecOps 2023

   The Call For Paper was open until 30 October 2023 at UTC. More info →

   • This is a virtual event

   • Online conference organized by Conf42.

   • The conference starts on the 30 November 2023.

   • Apply here

6. expired

   Devopsdays Birmingham (AL)

   The Call For Paper was open until 1 December 2023 at UTC. More info →

   • Location: Birmingham, AL, USA

   • In-person conference organized by Devopsdays.

   • The conference starts on the 18 April 2024.

   • Apply here

7. expired

   Great International Developer Summit

   The Call For Paper was open until 31 October 2023 at UTC. More info →

   • Location: Bengaluru, IN

   • In-person conference organized by Saltmarch.

   • The conference starts on the 23 April 2024.

   • Apply here

8. expired

   Devopsdays Los Angeles

   The Call For Paper was open until 1 November 2023 at UTC. More info →

   • Location: Los Angeles, CA, USA

   • In-person conference organized by Devopsdays.

   • The conference starts on the 15 March 2024.

   • Apply here

9. expired

   Devopsdays Istanbul

   The Call For Paper was open until 23 January 2024 at UTC. More info →

   • Location: Istanbul, TR

   • In-person conference organized by Devopsdays.

   • The conference starts on the 20 April 2024.

   • Apply here

Until next time!

— Dan

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