Kubernetes - Montior and Debug Applications 🕸️

Description 👀

Kubernetes runs an agent on each node known as a kubelet. The kubelet is responsible for ensuring that the containers are running in a pod. The kubelet also exposes a /metrics/cadvisor endpoint that provides metrics about the node and its containers. The kubelet uses cAdvisor to collect these metrics. cAdvisor is an open source project that collects resource usage and performance metrics about running containers. cAdvisor is built into the kubelet binary and is available at the /metrics/cadvisor endpoint on the kubelet.

Metrics Server 📊

The metrics server is a cluster-wide aggregator of resource usage data. The metrics server collects resource metrics from all nodes in the cluster, aggregates the data, and exposes the metrics via an API. The metrics server is not enabled by default in Kubernetes. To enable the metrics server, you must install the metrics server.

• minikube install

    minikube addons enable metrics-server
  

• other

    git clone https://github.com/kubernetes-incubator/metrics-serve
  

    kubectl create -f deploy/1.8+/
  

Basic Commands 📝

• view the metrics for the top performing nodes

    kubectl top nodes
  

• view the metrics for the top performing nodes in a namespace

    kubectl top nodes -n <namespace>
  

• view the node that consumes the most memory

    kubectl top node --sort-by='memory' --no-headers | head -1 
  

• view the node that consumes the least memory

    kubectl top node --sort-by='memory' --no-headers | tail -1
  

• view the node that consumes the most cpu

    kubectl top node --sort-by='cpu' --no-headers | head -1 
  

• view the node that consumes the most cpu

    kubectl top node --sort-by='cpu' --no-headers | tail -1 
  

• view the metrics for the top performing pods

    kubectl top pods
  

• view the metrics for the top performing pods in a namespace

    kubectl top pods -n <namespace>
  

• view the pod that consumes the most memory

    kubectl top pod --sort-by='memory' --no-headers | head -1 
  

• view the pod that consumes the least memory

    kubectl top pod --sort-by='memory' --no-headers | tail -1
  

• view the pod that consumes the most cpu

    kubectl top pod --sort-by='cpu' --no-headers | head -1 
  

• view the pod that consumes the most cpu

    kubectl top pod --sort-by='cpu' --no-headers | tail -1 
  

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