Breaking change in an upgrade

Cases

1. IL-0097 A cluster autoscaler version bump was incompatible with the one cluster still on Kubernetes 1.33, so no scale-up events fired and new nodes were not created2i2c · 2026
2. IL-0098 After 2i2c moved from ingress-nginx to nginx-ingress, a hub's Ingress took priority over cert-manager's temporary Ingress for the same host, so new hubs could not get TLS certificates2i2c · 2026
3. IL-0092 Upgrading ingress-nginx from 1.12.0 to 1.14.3 brought a newer ModSecurity and OWASP Core Rule Set whose false positives blocked HMPPS Auth, so users could not sign in to their applicationsUK Ministry of Justice · 2026
4. IL-0101 After Google forced a GKE control plane upgrade to 1.33.2 at a deprecation deadline, no new node could initialise, so autoscaling and spot node replacement stopped for 15 hoursWealthy · 2025 · sev1
5. IL-0120 A daily scheduled OS update restarted systemd-networkd on cloud-hosted GPU nodes, which conflicted with OpenAI's networking agent and removed all routes, cutting capacity for ChatGPT and the APIOpenAI · 2025
6. IL-0079 A GKE node auto-upgrade to an ubuntu_containerd image with a kernel regression left kube-proxy unable to apply its ip6tables rules, so load balancer health checks failed and several clusters lost all ingress trafficAltinity · 2025
7. IL-0201 A framework upgrade caused kernel panics in GitHub's Kubernetes infrastructure, and GitHub.com web and API requests, mostly for issues and pull requests, failed intermittently for about 16 hoursGitHub · 2025
8. IL-0117 A scheduled maintenance and an ingress upgrade on OpenAI's user-facing clusters caused a networking control plane regression that briefly broke the data plane, and the services that restarted then overwhelmed a backend persistence store with a heavy first-start queryOpenAI · 2024
9. A routine Kubernetes cluster system update made the AWS Load Balancer Controller fail, so new pods were never registered with the ALB and Honeycomb's EU1 ingest and UI went down once the last old pods were replaced