Kubernetes Metrics Server
You can find the user guide in the official Kubernetes documentation.
The detailed design of the project can be found in the following docs:
For the broader view of monitoring in Kubernetes take a look into Monitoring architecture
|Metrics Server||Metrics API group/version||Supported Kubernetes version|
In order to deploy metrics-server in your cluster run the following command from the top-level directory of this repository:
# Kubernetes 1.7 $ kubectl create -f deploy/1.7/ # Kubernetes > 1.8 $ kubectl create -f deploy/1.8+/
You can also use this helm chart to deploy the metric-server in your cluster (This isn't supported by the metrics-server maintainers): https://github.com/helm/charts/tree/master/stable/metrics-server
If you want to test
metric-server in a
minikube cluster, please follow the steps below:
$ minikube version minikube version: v1.2.0 # disable the metrics-server addon for minikube in case it was enabled, because it installs the email@example.com $ minikube addons disable metrics-server # now start a new minikube $ minikube delete; minikube start --extra-config=kubelet.authentication-token-webhook=true 🔥 Deleting "minikube" from virtualbox ... 💔 The "minikube" cluster has been deleted. 😄 minikube v1.2.0 on linux (amd64) 🔥 Creating virtualbox VM (CPUs=2, Memory=2048MB, Disk=20000MB) ... 🐳 Configuring environment for Kubernetes v1.15.0 on Docker 18.09.6 ▪ kubelet.authentication-token-webhook=true 🚜 Pulling images ... 🚀 Launching Kubernetes ... ⌛ Verifying: apiserver proxy etcd scheduler controller dns 🏄 Done! kubectl is now configured to use "minikube" # deploy the latest metric-server $ kubectl create -f deploy/1.8+/ clusterrole.rbac.authorization.k8s.io/system:aggregated-metrics-reader created clusterrolebinding.rbac.authorization.k8s.io/metrics-server:system:auth-delegator created rolebinding.rbac.authorization.k8s.io/metrics-server-auth-reader created apiservice.apiregistration.k8s.io/v1beta1.metrics.k8s.io created serviceaccount/metrics-server created deployment.extensions/metrics-server created service/metrics-server created clusterrole.rbac.authorization.k8s.io/system:metrics-server created clusterrolebinding.rbac.authorization.k8s.io/system:metrics-server created # edit metric-server deployment to add the flags # args: # - --kubelet-insecure-tls # - --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname $ kubectl edit deploy -n kube-system metrics-server
Metrics Server supports all the standard Kubernetes API server flags, as
well as the standard Kubernetes
glog logging flags. The most
commonly-used ones are:
--logtostderr: log to standard error instead of files in the container. You generally want this on.
--v=<X>: set log verbosity. It's generally a good idea to run a log level 1 or 2 unless you're encountering errors. At log level 10, large amounts of diagnostic information will be reported, include API request and response bodies, and raw metric results from Kubelet.
--secure-port=<port>: set the secure port. If you're not running as root, you'll want to set this to something other than the default (port 443).
--tls-private-key-file: the serving certificate and key files. If not specified, self-signed certificates will be generated, but it's recommended that you use non-self-signed certificates in production.
Additionally, Metrics Server defines a number of flags for configuring its behavior:
--metric-resolution=<duration>: the interval at which metrics will be scraped from Kubelets (defaults to 60s).
--kubelet-insecure-tls: skip verifying Kubelet CA certificates. Not recommended for production usage, but can be useful in test clusters with self-signed Kubelet serving certificates.
--kubelet-port: the port to use to connect to the Kubelet (defaults to the default secure Kubelet port, 10250).
--kubelet-preferred-address-types: the order in which to consider different Kubelet node address types when connecting to Kubelet. Functions similarly to the flag of the same name on the API server.