Kubernetes

Creating Objects Create resource: $ kubectl apply -f ./<file_name>.yaml Create from multiple files: $ kubectl apply -f ./<file_name_1>.yaml -f ./<file_name_2>.yaml Create all files in directory: $ kubectl apply -f ./<directory_name> Create from url: $ kubectl apply -f https://<url> Create pod: $ kubectl run <pod_name> –image <image_name> Create pod, then expose it as service: $ kubectl […]

The Problem Getting “Error: could not find a ready tiller pod” error when trying various helm commands. > helm version Client: &version.Version{SemVer:”v2.14.3″, GitCommit:”0e7f3b6637f7af8fcfddb3d2941fcc7cbebb0085″, GitTreeState:”clean”} Error: could not find a ready tiller pod The Solution This error is caused due to wrong configuration or version mismatch. Follow the procedure to install helm and tiller using the […]

Question: How to Schedule Master Node to Run Pod Workloads Like the Worker Node? By default, only the worker node can run the pod workloads and the master is only responsible for the scheduling and configuration. $ kubectl get nodes -o json | jq .items[].spec.taints [ { “effect”: “NoSchedule”, “key”: “node-role.kubernetes.io/master” } ] $ kubectl […]

Following is an alternative workaround to access Dashboard externally. 1. kubernetes-dashboard is a service file which provides dash-board functionality, to edit this we need to edit dashboard service and change service “type” from ClusterIP to NodePort: [root@kubeXXXX]# kubectl -n kube-system edit service kubernetes-dashboard # Please edit the object below. Lines beginning with a ‘#’ will […]

The Problem When run kubectl from a new created user, failed with error: The connection to the server xxx.xxx.xxx was refused – did you specify the right host or port? The Solution A newly created user has no KUBECONFIG configured. Setup kubernetes configuration for the new user: # mkdir -p $HOME/.kube # sudo cp -i […]

Question: How can I schedule master node running pod/service as worker node? By deafult, only worker node could run the pod, master only response for the scheduler/configuration. $ kubectl get nodes -o json | jq .items[].spec.taints [ { “effect”: “NoSchedule”, “key”: “node-role.kubernetes.io/master” } ] $ kubectl get nodes -o json | grep master “node-role.kubernetes.io/master”: “” […]

The Problem Endpoints shows ‘none’: $ kubectl get svc NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE kubernetes ClusterIP 10.yy.0.1 <none> 443/TCP 9d test ClusterIP 10.xx.97.97 <none> 6379/TCP 21s $ kubectl describe svc test Name: test Namespace: default Labels: <none> Annotations: kubectl.kubernetes.io/last-applied-configuration: {“apiVersion”:”v1″,”kind”:”Service”,”metadata”:{“annotations”:{},”name”:”test”,”namespace”:”default”},”spec”:{“clusterIP”:”10.xx.97.97″,”… Selector: app=test Type: ClusterIP IP: 10.xx.97.97 Port: <unset> 6379/TCP TargetPort: 6379/TCP Endpoints: <none> Session […]

This document describes steps to troubleshoot kubectl error: The connection to the server x.x.x.x:6443 was refused – did you specify the right host or port? 1. The kubectl should be executed on the Master Node. 2. Current user must have Kubernetes cluster configuration environment variable (Details of how to are listed under section Preparing to […]