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Tasks

Tasks
Install Tools
Install and Set Up kubectl
Install Minikube
Administer a Cluster
Administration with kubeadm
Upgrading kubeadm HA clusters from 1.9.x to 1.9.y
Upgrading kubeadm clusters from 1.7 to 1.8
Upgrading kubeadm clusters from v1.10 to v1.11
Upgrading/downgrading kubeadm clusters between v1.8 to v1.9
Manage Memory, CPU, and API Resources
Configure Default Memory Requests and Limits for a Namespace
Configure Default CPU Requests and Limits for a Namespace
Configure Minimum and Maximum Memory Constraints for a Namespace
Configure Minimum and Maximum CPU Constraints for a Namespace
Configure Memory and CPU Quotas for a Namespace
Configure a Pod Quota for a Namespace
Install a Network Policy Provider
Use Calico for NetworkPolicy
Use Cilium for NetworkPolicy
Use Kube-router for NetworkPolicy
Romana for NetworkPolicy
Weave Net for NetworkPolicy
Access Clusters Using the Kubernetes API
Access Services Running on Clusters
Advertise Extended Resources for a Node
Autoscale the DNS Service in a Cluster
Change the Reclaim Policy of a PersistentVolume
Change the default StorageClass
Cluster Management
Configure Multiple Schedulers
Configure Out Of Resource Handling
Configure Quotas for API Objects
Control CPU Management Policies on the Node
Customizing DNS Service
Debugging DNS Resolution
Declare Network Policy
Developing Cloud Controller Manager
Encrypting Secret Data at Rest
Guaranteed Scheduling For Critical Add-On Pods
IP Masquerade Agent User Guide
Kubernetes Cloud Controller Manager
Limit Storage Consumption
Namespaces Walkthrough
Operating etcd clusters for Kubernetes
Reconfigure a Node's Kubelet in a Live Cluster
Reserve Compute Resources for System Daemons
Safely Drain a Node while Respecting Application SLOs
Securing a Cluster
Set Kubelet parameters via a config file
Set up High-Availability Kubernetes Masters
Share a Cluster with Namespaces
Static Pods
Storage Object in Use Protection
Using CoreDNS for Service Discovery
Using a KMS provider for data encryption
Using sysctls in a Kubernetes Cluster
Configure Pods and Containers
Assign Memory Resources to Containers and Pods
Assign CPU Resources to Containers and Pods
Configure Quality of Service for Pods
Assign Extended Resources to a Container
Configure a Pod to Use a Volume for Storage
Configure a Pod to Use a PersistentVolume for Storage
Configure a Pod to Use a Projected Volume for Storage
Configure a Security Context for a Pod or Container
Configure Service Accounts for Pods
Pull an Image from a Private Registry
Configure Liveness and Readiness Probes
Assign Pods to Nodes
Configure Pod Initialization
Attach Handlers to Container Lifecycle Events
Configure a Pod to Use a ConfigMap
Share Process Namespace between Containers in a Pod
Translate a Docker Compose File to Kubernetes Resources
Inject Data Into Applications
Define a Command and Arguments for a Container
Define Environment Variables for a Container
Expose Pod Information to Containers Through Environment Variables
Expose Pod Information to Containers Through Files
Distribute Credentials Securely Using Secrets
Inject Information into Pods Using a PodPreset
Run Applications
Run a Stateless Application Using a Deployment
Run a Single-Instance Stateful Application
Run a Replicated Stateful Application
Update API Objects in Place Using kubectl patch
Scale a StatefulSet
Delete a StatefulSet
Force Delete StatefulSet Pods
Perform Rolling Update Using a Replication Controller
Horizontal Pod Autoscaler
Horizontal Pod Autoscaler Walkthrough
Specifying a Disruption Budget for your Application
Run Jobs
Running Automated Tasks with a CronJob
Parallel Processing using Expansions
Coarse Parallel Processing Using a Work Queue
Fine Parallel Processing Using a Work Queue
Access Applications in a Cluster
Web UI (Dashboard)
Accessing Clusters
Configure Access to Multiple Clusters
Use Port Forwarding to Access Applications in a Cluster
Provide Load-Balanced Access to an Application in a Cluster
Use a Service to Access an Application in a Cluster
Connect a Front End to a Back End Using a Service
Create an External Load Balancer
Configure Your Cloud Provider's Firewalls
List All Container Images Running in a Cluster
Communicate Between Containers in the Same Pod Using a Shared Volume
Configure DNS for a Cluster
Monitor, Log, and Debug
Application Introspection and Debugging
Auditing
Core metrics pipeline
Debug Init Containers
Debug Pods and ReplicationControllers
Debug Services
Debug a StatefulSet
Debugging Kubernetes nodes with crictl
Determine the Reason for Pod Failure
Developing and debugging services locally
Events in Stackdriver
Get a Shell to a Running Container
Logging Using Elasticsearch and Kibana
Logging Using Stackdriver
Monitor Node Health
Tools for Monitoring Resources
Troubleshoot Applications
Troubleshoot Clusters
Troubleshooting
Extend Kubernetes
Use Custom Resources
Extend the Kubernetes API with CustomResourceDefinitions
Versions of CustomResourceDefinitions
Migrate a ThirdPartyResource to CustomResourceDefinition
Configure the Aggregation Layer
Setup an Extension API Server
Use an HTTP Proxy to Access the Kubernetes API
TLS
Certificate Rotation
Manage TLS Certificates in a Cluster
Federation - Run an App on Multiple Clusters
Cross-cluster Service Discovery using Federated Services
Set up Cluster Federation with Kubefed
Set up CoreDNS as DNS provider for Cluster Federation
Set up placement policies in Federation
Manage Cluster Daemons
Perform a Rollback on a DaemonSet
Perform a Rolling Update on a DaemonSet
Install Service Catalog
Install Service Catalog using Helm
Install Service Catalog using SC
Federation - Run an App on Multiple Clusters
Federated Cluster
Federated ConfigMap
Federated DaemonSet
Federated Deployment
Federated Events
Federated Horizontal Pod Autoscalers (HPA)
Federated Ingress
Federated Jobs
Federated Namespaces
Federated ReplicaSets
Federated Secrets
Extend kubectl with plugins
Manage HugePages
Schedule GPUs

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Certificate Rotation

This page shows how to enable and configure certificate rotation for the kubelet.

Before you begin

Overview

The kubelet uses certificates for authenticating to the Kubernetes API. By default, these certificates are issued with one year expiration so that they do not need to be renewed too frequently.

Kubernetes 1.8 contains kubelet certificate rotation, a beta feature that will automatically generate a new key and request a new certificate from the Kubernetes API as the current certificate approaches expiration. Once the new certificate is available, it will be used for authenticating connections to the Kubernetes API.

Enabling client certificate rotation

The kubelet process accepts an argument --rotate-certificates that controls if the kubelet will automatically request a new certificate as the expiration of the certificate currently in use approaches. Since certificate rotation is a beta feature, the feature flag must also be enabled with --feature-gates=RotateKubeletClientCertificate=true.

The kube-controller-manager process accepts an argument --experimental-cluster-signing-duration that controls how long certificates will be issued for.

Understanding the certificate rotation configuration

When a kubelet starts up, if it is configured to bootstrap (using the --bootstrap-kubeconfig flag), it will use its initial certificate to connect to the Kubernetes API and issue a certificate signing request. You can view the status of certificate signing requests using:

kubectl get csr

Initially a certificate signing request from the kubelet on a node will have a status of Pending. If the certificate signing requests meets specific criteria, it will be auto approved by the controller manager, then it will have a status of Approved. Next, the controller manager will sign a certificate, issued for the duration specified by the --experimental-cluster-signing-duration parameter, and the signed certificate will be attached to the certificate signing requests.

The kubelet will retrieve the signed certificate from the Kubernetes API and write that to disk, in the location specified by --cert-dir. Then the kubelet will use the new certificate to connect to the Kubernetes API.

As the expiration of the signed certificate approaches, the kubelet will automatically issue a new certificate signing request, using the Kubernetes API. Again, the controller manager will automatically approve the certificate request and attach a signed certificate to the certificate signing request. The kubelet will retrieve the new signed certificate from the Kubernetes API and write that to disk. Then it will update the connections it has to the Kubernetes API to reconnect using the new certificate.