Note: Dockershim has been removed from the Kubernetes project as of release 1.24. Read the Dockershim Removal FAQ for further details. FEATURE STATE: Kubernetes v1.11 [stable] The lifecycle of the kubeadm CLI tool is decoupled from the kubelet, which is a daemon that runs on each node within the Kubernetes cluster. The kubeadm CLI tool is executed by the user when Kubernetes is initialized or upgraded, whereas the kubelet is always running in the background.| Kubernetes
This page covers how to customize the components that kubeadm deploys. For control plane components you can use flags in the ClusterConfiguration structure or patches per-node. For the kubelet and kube-proxy you can use KubeletConfiguration and KubeProxyConfiguration, accordingly. All of these options are possible via the kubeadm configuration API. For more details on each field in the configuration you can navigate to our API reference pages. Note:Customizing the CoreDNS deployment of kubead...| Kubernetes
Before you begin Some steps in this page use the jq tool. If you don't have jq, you can install it via your operating system's software sources, or fetch it from https://jqlang.github.io/jq/. Some steps also involve installing curl, which can be installed via your operating system's software sources. A subset of the kubelet's configuration parameters may be set via an on-disk config file, as a substitute for command-line flags. Providing parameters via a config file is the recommended approac...| Kubernetes
FEATURE STATE: Kubernetes v1.26 [stable] Kubernetes keeps many aspects of how pods execute on nodes abstracted from the user. This is by design. However, some workloads require stronger guarantees in terms of latency and/or performance in order to operate acceptably. The kubelet provides methods to enable more complex workload placement policies while keeping the abstraction free from explicit placement directives. For detailed information on resource management, please refer to the Resource ...| Kubernetes
Application logs can help you understand what is happening inside your application. The logs are particularly useful for debugging problems and monitoring cluster activity. Most modern applications have some kind of logging mechanism. Likewise, container engines are designed to support logging. The easiest and most adopted logging method for containerized applications is writing to standard output and standard error streams. However, the native functionality provided by a container engine or ...| Kubernetes
Anyone who is running Kubernetes in a large-scale production setting cares about having a predictable Pod lifecycle. But there are so many ways Kubernetes terminates workloads, each one working in non-trivial (and not always predictable) ways. These...| ahmet.im
A ConfigMap is an API object used to store non-confidential data in key-value pairs. Pods can consume ConfigMaps as environment variables, command-line arguments, or as configuration files in a volume. A ConfigMap allows you to decouple environment-specific configuration from your container images, so that your applications are easily portable. Caution:ConfigMap does not provide secrecy or encryption. If the data you want to store are confidential, use a Secret rather than a ConfigMap, or use...| Kubernetes
Static Pods are managed directly by the kubelet daemon on a specific node, without the API server observing them. Unlike Pods that are managed by the control plane (for example, a Deployment); instead, the kubelet watches each static Pod (and restarts it if it fails). Static Pods are always bound to one Kubelet on a specific node. The kubelet automatically tries to create a mirror Pod on the Kubernetes API server for each static Pod.| Kubernetes
A container image represents binary data that encapsulates an application and all its software dependencies. Container images are executable software bundles that can run standalone and that make very well-defined assumptions about their runtime environment. You typically create a container image of your application and push it to a registry before referring to it in a Pod. This page provides an outline of the container image concept. Note:If you are looking for the container images for a Kub...| Kubernetes
Kubernetes runs your workload by placing containers into Pods to run on Nodes. A node may be a virtual or physical machine, depending on the cluster. Each node is managed by the control plane and contains the services necessary to run Pods. Typically you have several nodes in a cluster; in a learning or resource-limited environment, you might have only one node. The components on a node include the kubelet, a container runtime, and the kube-proxy.| Kubernetes
Kubernetes nodes can be scheduled to Capacity. Pods can consume all the available capacity on a node by default. This is an issue because nodes typically run quite a few system daemons that power the OS and Kubernetes itself. Unless resources are set aside for these system daemons, pods and system daemons compete for resources and lead to resource starvation issues on the node. The kubelet exposes a feature named 'Node Allocatable' that helps to reserve compute resources for system daemons.| Kubernetes
Garbage collection is a collective term for the various mechanisms Kubernetes uses to clean up cluster resources. This allows the clean up of resources like the following: Terminated pods Completed Jobs Objects without owner references Unused containers and container images Dynamically provisioned PersistentVolumes with a StorageClass reclaim policy of Delete Stale or expired CertificateSigningRequests (CSRs) Nodes deleted in the following scenarios: On a cloud when the cluster uses a cloud c...| Kubernetes
This command initializes a Kubernetes control plane node. Run this command in order to set up the Kubernetes control plane Synopsis Run this command in order to set up the Kubernetes control plane The "init" command executes the following phases: preflight Run pre-flight checks certs Certificate generation /ca Generate the self-signed Kubernetes CA to provision identities for other Kubernetes components /apiserver Generate the certificate for serving the Kubernetes API /apiserver-kubelet-clie...| Kubernetes
I’ve recently done a Twitter poll and only 20% of the participants accurately predicted that it takes Kubernetes 60-90 seconds to propagate changes to Secrets and ConfigMaps on the mounted volumes. So I want to take you on a journey in the...| ahmet.im
When you specify a Pod, you can optionally specify how much of each resource a container needs. The most common resources to specify are CPU and memory (RAM); there are others. When you specify the resource request for containers in a Pod, the kube-scheduler uses this information to decide which node to place the Pod on. When you specify a resource limit for a container, the kubelet enforces those limits so that the running container is not allowed to use more of that resource than the limit ...| Kubernetes
Note: Dockershim has been removed from the Kubernetes project as of release 1.24. Read the Dockershim Removal FAQ for further details. You need to install a container runtime into each node in the cluster so that Pods can run there. This page outlines what is involved and describes related tasks for setting up nodes. Kubernetes 1.33 requires that you use a runtime that conforms with the Container Runtime Interface (CRI).| Kubernetes
A Secret is an object that contains a small amount of sensitive data such as a password, a token, or a key. Such information might otherwise be put in a Pod specification or in a container image. Using a Secret means that you don't need to include confidential data in your application code. Because Secrets can be created independently of the Pods that use them, there is less risk of the Secret (and its data) being exposed during the workflow of creating, viewing, and editing Pods.| Kubernetes