A few days ago I implemented the horizontal pod auto scaling for our application based on customer metrics in the Kubernetes. During the implementation, I setup a Prometheus server to gather metrics from the application and setup a Prometheus-Adapter to… Read More
crd-install for apiextensions.k8s.io/v1 does not work in helm v2 command
A few days ago, when I tried to install the below application with the latest helm chart using helm v2 command, I got an error message complaining that the helm chart is a helm v3 chart. https://github.com/prometheus-community/helm-charts/tree/main/charts/kube-prometheus-stack After struggling for… Read More
a few kubectl command examples
In this post, I will list a few examples for kubectl comman, which can be referenced in daily work. 1. create tls secret kubectl create secret tls secret-name –cert=/path/to/cert –key=/path/to/key 2. get information from pod get the ready status of… Read More
Kubernetes pod termination events
A few days ago I was assigned a user story to investigate the upgrade of our application in Kubernetes environment without breaking the application servicing customers. One key point in this story is to find out how the Kubernetes pods terminates.… Read More
remove node from Kubernetes cluster safely
Confirm the name of the node you want to remove, and make sure that the pods on the node can be terminated. The pod list can be retrieved using the below command: kubectl get nodes Mark the node as unschedulable… Read More
chrome does not use commonName to verify site certificate
I showed how to create a self-signed certificate using openssl command line in this post. However, after I created a self-signed certificate using the similar openssl command and deployed the certificate in a Kubernete ingress, I always got a warning… Read More
在RHEL7上搭建kubernetes 1.11集群
在RHEL7的虚拟机上搭建一个kubernetes 1.11集群，环境如下 master: 192.168.10.1 node1: 192.168.10.2 node2: 192.168.10.3
setup an externally accessible etcd in kubernetes
As we know, the IP addresses of pods and services in kubernetes are not accessible from the outside of the kubernetes cluster. In order for an application deployed in kubernetes to be reached from the outside of the kuberenetes, different… Read More
nslookup in busybox 1.29 does not work in kubernetes
Recently I was trying to use nslookup in pod initContainers in order to make sure that some services are available during pod startup. However, it didn’t work when I was using nslookup from busybox:1.29. After several tries, the DNS lookup still failed. I… Read More