KUBERNETES

 To obtain the kubeconfig file for your Kubernetes cluster on Amazon EKS (Elastic Kubernetes Service), you can use the AWS Command Line Interface (AWS CLI). Here are the steps: Install the AWS CLI: If you haven't already installed the AWS CLI, you can follow the instructions provided in the official AWS CLI User Guide: Installing the AWS CLI Configure AWS CLI: Run the following command to configure the AWS CLI with your AWS access key, secret key, region, and output format: aws configure   Obtain kubeconfig: Use the update-kubeconfig command to create or update the kubeconfig file for your EKS cluster. Replace <cluster-name> with the name of your EKS cluster and <region> with your AWS region.  aws eks --region <region> update-kubeconfig --name <cluster-name>  For example: aws eks --region us-west-2 update-kubeconfig --name my-eks-cluster   This command downloads the kubeconfig file and updates your local kubeconfig file. The kube...

 ctr | nerctl | crictl  What are these cli tools and which one should you be using.  Kubernetes Introduced something called Container run time interface - CRI   CRI Allowed any vendor to work as a container run time from kubernetes as long as they followed the standard as long as they adhered to the OCI standards.  OCI : Stands for Open Container Initiative   It consists of a image spec and a run time spec Image Spec : Is how an image should be built Runtime Spec : specified how a run time should be developed Keeping these standards in mind any one can build a run time . Therefore RKT and Container run time adhered to the OCI standards and were then supported as container run time for kubernetes via the CRI However Docker wasnt build to support the CRI standards . Docker was build way before CRI was introduced and Docker still was the dominant container tool used by most so Kubernetes had to continue to support docker as well . Therefore kubernetes in...

 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++    ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ : Networking : From Linux perspective : Networking : Switching How does system A reach B , we connect them to a switch and the switch creates a network containing the two systems . To connect them to a switch we need an interface on both the nodes. Physical or virtual depends on the host.  To see the interfaces for the host we use the IP link command . In this case we will see the interface called eth0 that we will be using to connect to the switch. In this case we see an interface named eth0 , that we will be using to connect to the switch . Lets assume is a network with 192.168.1.0 We then assign the ip addresses to the systems on the same network.  For this we use the command ip addr , once the link is up and IP Addresses are assigned. The computers can now communicate to one another through the switch ...

 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++    +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++     Kubernetes monitoring solutions are tools and platforms designed to help you monitor and observe the health, performance, and behavior of your Kubernetes clusters and the applications running within them. These solutions provide insights into various aspects of your Kubernetes environment, such as resource utilization, application metrics, logs, and more. Here are some popular Kubernetes monitoring solutions: Prometheus: An open-source monitoring and alerting toolkit. Collects metrics from various sources, including Kubernetes nodes, pods, and services. Provides a powerful querying language (PromQL) for analyzing metrics data. Integrates with Grafana for creating dashboards and visualizations. Grafana: A popular open-source platform for creating dashboards and visualizing time-series data. Works well ...

 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ https://github.com/kodekloudhub/certified-kubernetes-administrator-course/blob/master/docs/04-Logging-and-Monitoring/02-Monitor-Cluster-Components.md Kubernetes Release Page for Downloads  https://kubernetes.io/releases/ CKA Exam :  https://www.youtube.com/watch?v=9UqkWcdy140 Exam Point of view : Imperative commands https://www.udemy.com/course/certified-kubernetes-administrator-with-practice-tests/learn/lecture/15018998#overview https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands https://kubernetes.io/docs/reference/kubectl/conventions/ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Sec: 2 : Core Concepts : 11. Cluster Architecture We are taking Two ships as an analogy for the explaination.  12. Docker-vs-ContainerD CLI tools 1. ctr 2. crictl 3. nerdctl What are the CLI tools and which one should you be using. Back then kubernetes only worked...