From 9f9371bd71cb8fe2397c406817a22f7e0ef178d3 Mon Sep 17 00:00:00 2001
From: Nicolai Ort <info@nicolai-ort.com>
Date: Sat, 21 Mar 2026 15:57:53 +0100
Subject: [PATCH] docs(day-2): Added multitenancy talk

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 content/_index.md                |  2 ++
 content/day-2/08-multitenancy.md | 33 ++++++++++++++++++++++++++++++++
 content/day2/_index.md           | 12 +-----------
 3 files changed, 36 insertions(+), 11 deletions(-)
 create mode 100644 content/day-2/08-multitenancy.md

diff --git a/content/_index.md b/content/_index.md
index 96d21ce..ea48981 100644
--- a/content/_index.md
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@@ -9,6 +9,8 @@ This "blog" certainly contains a bunch of tyops.
 This is what typing the notes blindly in real time get's you.
 Every year I tell myself that I will fix them afterwards: To be fair I fix most of them but not all and that's fine.
 
+Also the notes tend to start out strong early in the week (aka Rejekts + CloudNativeCon) and fall off in terms of density and depth.
+
 ## How did I get there?
 
 I attended Cloud Native Rejekts and KubeCon + CloudNativeCon Europe 2026 in Amsterdam.
diff --git a/content/day-2/08-multitenancy.md b/content/day-2/08-multitenancy.md
new file mode 100644
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@@ -0,0 +1,33 @@
+---
+title: "Push the boundaries of kubernetes multi-tenancy with containerruntimeclasses"
+weight: 8
+tags:
+ - rejekts
+ - runtime
+---
+
+<!-- {{% button href="https://youtu.be/rkteV6Mzjfs" style="warning" icon="video" %}}Watch talk on YouTube{{% /button %}} -->
+<!-- {{% button href="https://docs.google.com/presentation/d/1nEK0CVC_yQgIDqwsdh-PRihB6dc9RyT-" style="tip" icon="person-chalkboard" %}}Slides{{% /button %}} -->
+<!-- {{% button href="https://github.com/graz-dev/automatic-reosurce-optimization-loop" style="info" icon="code" %}}Code/Demo{{% /button %}}  -->
+
+I missed the first 3 minutes of this talk because they started ealy so the notes are currently missing the first levels of multi-tenancy
+This was a real interesting introduction into the world of runtime classes and how you could use them to choose the right level of isolation for each of your pods/deployments utilizing different runtimes/shims. Running everything from normal containers to hardened/Emulated processes and vms side-by-side in kubernetes.
+
+## Levels of multi-tenancy
+
+- God-Level: A physical clusters seperated out in multiple virtual clusters which can be isolated into even more nested virtual clusters (for )
+- Problem: We're using the same container runtime
+
+## Runtimes
+
+- There are different runtimes since TODO -> They replaced dockershim as the runtime in 1.24
+- Choice can range from cri-o )performant) to kata containers (secure)
+- In the past there was no plugin architecture (node had to be reinstalled and restarted to switch cri) now you just have to update the container confug through a new RuntimeClass
+- Can be targeted for each Pod/Deployment Spec
+- You can still use containerd as the default class with shims (Shim v2 Project) for specialized runtimes like kata or windows
+- Expansion: KubeVirt - vms as a runtime class (also implemented by others like kata with qemu isolation)
+
+## Pro/Con
+
+- Pro: Security, Cost optimization, Performance optimization, diversity/flexibility
+- Con: Day2 complexity, complex debugging (anyone say networking), additional costs of using VMs
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diff --git a/content/day2/_index.md b/content/day2/_index.md
index b345885..8fb0b31 100644
--- a/content/day2/_index.md
+++ b/content/day2/_index.md
@@ -8,14 +8,4 @@ TODO:
 
 ## Other stuff I learned or people i talk to
 
-- Isovalent
-- Kubermatic
-- Portworx
-- Fastly
-- Syseleven
-- Netbird
-- VMware
-- Stackit
-- Harness
-- Mia Platform
-- and many, many more...
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+- TODO:
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