Incident Library
Applied filters SymptomResources deletedFactorNo safeguard on destructive changeClear allEvery case under the filters, with no sentence; newest first.
Suggested filters Search, and the values found in your words appear here.

Graph

  • Root cause
  • Component
  • Symptom
  • Contributing factor
  • Case

Cases8 cases

7 to 8 of 8

  1. IL-0089 A test cluster deletion script run with the kube context pointing at the live-1 production cluster deleted its ingress controller, monitoring, logging, cert-manager, kiam and external-dns
    UK Ministry of Justice2020
    Symptoms

    At 18:27 on 21 September 2020 the Cloud Platform team detected that some services running on the live-1 production cluster had gone down, and some users could not reach them. The incident was declared at 18:40.

    Service outageResources deletedMonitoring outageStale endpoint routing
    Trigger

    A script for deleting a test cluster was triggered while the kube context was pointing at the live-1 production cluster instead of the test cluster.

    Root cause
    Operator error
    Component
    Ingress controllerCredential broker for podsexternal-dnsCloud load balancerPrometheus
    Contributing factor
    No safeguard on destructive change
    Detection

    The first detection was at 18:27, and the incident was declared 13 minutes later, at 18:40.

    Remediation
    • restored the default ingress controller together with external-dns and kiam, which it depends on
    • corrected the owner field in the Formbuilder Route 53 TXT records so external-dns pointed their A records at the new NLB
    • restored the remaining components with a targeted apply
    • ran the apply pipeline to restore all certificates, ServiceMonitors and Prometheus rules from the environment repository
    View case
  2. IL-0061 A Terraform pull request merged out of order deleted a production GKE cluster, and recreating it deleted a second one
    Spotify2019
    Symptoms

    Terraform, applied from the shared cluster configuration repository after a merge, deleted Spotify's production GKE cluster in Asia. While the team tried to recreate it, Terraform deleted a second production cluster, so two of the three production clusters were gone.

    Resources deleted
    Trigger

    A feature team's pull request that added three users to an existing RBAC role binding file was merged before the cluster operators' pull request that imported the Asia cluster into Terraform state. The review build of the import pull request had already written the cluster into the shared state file, and the merged configuration had no definition of the Asia cluster, so Terraform removed it.

    Root cause
    Configuration change
    Component
    TerraformCI systemGKE control plane
    Contributing factor
    No safeguard on destructive changeMissed in reviewUnverified assumption
    Detection

    Internal service discovery could not reach the deleted cluster and the cluster operator team was paged.

    Remediation
    • removed the deleted clusters from the service discovery configuration and restarted service discovery so clients fell back to the instances outside Kubernetes
    • one team that ran half on Kubernetes and half on VMs created more VMs outside Kubernetes to handle the load
    • recreated the clusters, using the hourly backups
    • updated the places where the old clusters' master IPs were hardcoded
    Action items
    • Post the Terraform dry-run output as a comment on each pull request
    • Require a status check that the branch is up to date with master, so the dry run reflects what will actually happen
    • Require an approving review on pull requests
    • Fail reviews automatically when certain keywords such as destroy appear; cluster deletions are done manually outside this repository
    • Add linters and validators for the cluster configuration
    • Schedule and announce disaster recovery tests that cover a cluster going away and smaller failures
    Lessons

    Plan for failure from the start and migrate large infrastructure gradually, so there is redundancy and a way back. A backup whose restore has never been tested is not a backup. Practising disaster recovery paid off: restoring the first deleted cluster took three and a quarter hours, and the team can now restore a larger cluster in one hour. What matters is not who made the mistake but what was learned from it.

    View case
Check your cluster for this

These 8 cases involve Argo CD and Cloud load balancer. kubegap audits a Kubernetes cluster for gaps like these, read-only, from Claude Code or Codex; its checks cite public reports like the ones in this library.

Open kubegap

By root cause3

Software defect1 case

Component
Argo CD
Contributing factor
Unverified assumptionHarmful manual actionNo safeguard on destructive change
Organisation
Argo CD users
  1. IL-0058 Argo CD deleted namespaces shared by several applications, leaving about 97 applications stuck Missing and OutOfSync
    Argo CD users2026

Operator error3 cases

Component
Ingress controller2Cloud load balancer1Credential broker for pods1Application database1external-dns1Jobs and CronJobs1Persistent volumes and stateful sets1Prometheus1Terraform1
Contributing factor
No safeguard on destructive change3No runbook1
Organisation
2i2c1GitLab1UK Ministry of Justice1
  1. IL-0095 An engineer deleted the prod namespace of the LEAP JupyterHub while believing the kubeconfig pointed at a new cluster, and the hub was down for about an hour
    2i2c2025
  2. IL-0207 A routine task run from an engineer's local environment switched to production and deleted GitLab.com's Consul release, so Patroni lost Consul and GitLab.com returned 5xx errors to all traffic
    GitLab2022
  3. IL-0089 A test cluster deletion script run with the kube context pointing at the live-1 production cluster deleted its ingress controller, monitoring, logging, cert-manager, kiam and external-dns
    UK Ministry of Justice2020

Configuration change4 cases

Component
Configuration templating2Argo CD1CI system1Cloud load balancer1etcd1GKE control plane1Kubernetes API server1Persistent volumes and stateful sets1Terraform1
Contributing factor
No safeguard on destructive change4Unverified assumption2Automation amplification2Excessive blast radius2Missed in review2Monitoring blind spot1No runbook1No staged rollout1
Organisation
DigitalOcean1Grafana Labs1InfluxData1Spotify1
  1. IL-0192 A Crossplane composition merge-policy change for a TLS policy update switched Kubernetes Services from LoadBalancer to ClusterIP and deleted the load balancers behind about 25% of Grafana Cloud services
    Grafana Labs2025
  2. IL-0152 An incorrect configuration applied during maintenance made an internal infrastructure cluster automatically delete the control planes of 200 DOKS clusters in FRA1
    DigitalOcean2024
  3. IL-0009 A duplicated generated name made Argo CD replace the InfluxDB Cloud production Application and delete the whole production environment
    InfluxData2022
  4. IL-0061 A Terraform pull request merged out of order deleted a production GKE cluster, and recreating it deleted a second one
    Spotify2019