50 Kubernetes (K8s) Errors and Solutions
Kubernetes also known as K8s is an open source platform for containerized applications which can automate the deployment, scaling up & down, and manage. Originally K8s is developed by Google and now it is being maintained by the Cloud Native Computing Foundation (CNCF).
Why we say Kubernetes as K8s ?
Kubernetes shorthand notation is K8s. The primarily reason to use shorthand notation is to simplify its spelling and pronunciation. The term “Kubernetes” itself comes from the Greek word κυβερνήτης (kybernetes) which means “helmsman” or “pilot,” reflecting its application in steering and managing containerized applications. The explanation is below why it is called K8s.
- The word count in Kubernetes has 10 characters in total.
- By taking the first letter (K) and the last letter (s) and replacing the 8 letters in between with the digit 8, it becomes K8s.
50 Kubernetes Errors and Solutions
Here is the list of 50 Kubernetes errors and solutions, covering common scenarios and their fixes.
- Cluster Creation Issues
- Error: Failed to initialize Kubernetes cluster (e.g.,
kubeadm init
fails).
Solution: Check network settings and disable swap (swapoff -a
). - Error: Node not joining the cluster.
Solution: Verify token validity and connectivity to the control plane. - Error: Unsupported Kubernetes version.
Solution: Upgradekubectl
,kubeadm
, andkubelet
to compatible versions.
- Error: Failed to initialize Kubernetes cluster (e.g.,
-
Pod Issues
- Error: Pod stuck in
Pending
state.
Solution: Ensure sufficient cluster resources and checkkubectl describe pod
. - Error: Pod in
CrashLoopBackOff
.
Solution: Analyze logs withkubectl logs
and debug application errors. - Error: Container not starting.
Solution: Verify image name, tag, and pull policy. - Error: Pod cannot connect to another pod.
Solution: Verify network policies and DNS resolution.
- Error: Pod stuck in
-
Service and Networking
- Error: Service not exposing pod.
Solution: Check labels in the pod selector match the pod labels. - Error: External IP not assigned to LoadBalancer service.
Solution: Ensure cloud provider integration is configured correctly. - Error: DNS resolution failure.
Solution: Checkkube-dns
orCoreDNS
logs. - Error: NodePort service inaccessible.
Solution: Verify firewall and network configuration.
- Error: Service not exposing pod.
-
Persistent Volumes and Storage
- Error: PVC stuck in
Pending
.
Solution: Ensure StorageClass is available and matches PVC requirements. - Error: PV not bound to PVC.
Solution: Verify access modes and storage capacity match. - Error: Read-only file system error in container.
Solution: Check volume mount configurations.
- Error: PVC stuck in
-
Deployment Issues
- Error: Deployment update fails.
Solution: Check for immutable field changes. - Error: Rolling update stuck.
Solution: Inspect pod readiness and health checks. - Error: Unexpected scaling behavior.
Solution: Adjust HPA (Horizontal Pod Autoscaler) settings and CPU/memory limits.
- Error: Deployment update fails.
-
RBAC (Role-Based Access Control)
- Error:
Forbidden
error when accessing resources.
Solution: Assign proper roles and bindings to the user/service account. - Error: ServiceAccount not found.
Solution: Ensure theServiceAccount
exists in the correct namespace.
- Error:
-
Cluster Node Issues
- Error: Node marked as
NotReady
.
Solution: Check kubelet logs and verify node resources. - Error: Node eviction due to high memory usage.
Solution: Adjust eviction thresholds and monitor resource usage. - Error: DaemonSet pod not running on a node.
Solution: Verify taints and tolerations.
- Error: Node marked as
-
Ingress Issues
- Error: 404 response from Ingress.
Solution: Check Ingress rules and ensure the backend service is reachable. - Error: Ingress TLS configuration not working.
Solution: Verify secret for TLS and ensure certificates are valid.
- Error: 404 response from Ingress.
-
Image Pull Issues
- Error: Image pull back-off.
Solution: Verify image repository credentials. - Error: Invalid image reference.
Solution: Ensure the image name and tag are correct.
- Error: Image pull back-off.
-
Autoscaling Issues
- Error: HPA not scaling pods. e.g. HPA status shows “Desired Replicas: 1” despite high load.
Solution: Verify metrics-server is running and reachable. use command kubectl get deployment metrics-server -n kube-system - Error: ClusterAutoscaler not provisioning nodes.
Solution: Check resource requests and limits for scalability.
- Error: HPA not scaling pods. e.g. HPA status shows “Desired Replicas: 1” despite high load.
-
Security
- Error: Pod cannot mount secrets/configmaps.
Solution: Ensure RBAC permissions for the pod’s ServiceAccount. - Error: Unauthorized error accessing API server.
Solution: Verify API token and RBAC permissions.
- Error: Pod cannot mount secrets/configmaps.
-
Helm
- Error: Helm release upgrade failed.
Solution: Usehelm rollback
and analyze release history. - Error: Chart values not applied.
Solution: Ensure correctvalues.yaml
format.
- Error: Helm release upgrade failed.
-
Monitoring
- Error: Prometheus not scraping metrics.
Solution: Check scrape config and target pod annotations. - Error: Grafana dashboards missing data.
Solution: Verify data source connectivity.
- Error: Prometheus not scraping metrics.
-
Logging
- Error: Fluentd/Log collector not capturing logs.
Solution: Ensure log file paths are correct and accessible. - Error: Logs missing in EFK stack.
Solution: Check Elasticsearch and Fluentd integration.
- Error: Fluentd/Log collector not capturing logs.
-
Upgrades
- Error:
kubeadm upgrade
fails.
Solution: Follow the official upgrade path and resolve pre-check issues. - Error: Downtime during cluster upgrade.
Solution: Use surge upgrades or partitioned node upgrades.
- Error:
-
Performance
- Error: High API server latency.
Solution: Enable caching and optimize API requests. - Error: Resource starvation on nodes.
Solution: Optimize pod resource requests and cluster autoscaling.
- Error: High API server latency.
-
Advanced Scenarios
- Error: ClusterIP service unreachable.
Solution: Verifyiptables
orebpf
rules. - Error: CoreDNS pod crash.
Solution: Check CoreDNS configmap for errors. - Error: Pod security policy blocking deployment.
Solution: Update PSP to allow the required permissions.
- Error: ClusterIP service unreachable.
-
Miscellaneous
- Error:
kube-proxy
not working.
Solution: Restartkube-proxy
daemon and check its logs. - Error: Metrics-server not running.
Solution: Verify APIService and certificate configuration. - Error: ETCD out of disk space.
Solution: Clean up unused data or scale storage capacity. - Error: Scheduler not placing pods.
Solution: Check pod tolerations and node taints. - Error: Incorrect time sync across nodes.
Solution: Ensurentp
orchrony
is running. - Error: kube-apiserver down.
Solution: Check control plane node health and logs. - Error: Network plugin failure.
Solution: Restart the plugin and check configurations.
- Error:
By addressing these 50 errors and solutions, you can build a robust Kubernetes environment that supports reliable and scalable application deployments
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