Debug School: Vijay Chakravarthy G

Assignment - Pod, Deployment, Service

Vijay Chakravarthy G — Wed, 19 Oct 2022 09:29:58 +0000

Pods are atomic and most basic deployable objects in Kubernetes. A Pod represents a single instance of a running process in your cluster. Pods contain one or more containers, such as Docker containers. Pods are ephemeral by nature.

Deployment tells Kubernetes how to create or modify instances of the pods that hold a containerized application. Deployments can help to efficiently scale the number of replica pods, enable the rollout of updated code in a controlled manner, or roll back to an earlier deployment version if necessary.

Features of deployment are Replication, Controller, Versioning, Rollout and Rollback.

A service is a network load balancer.

1. Kubernetes Architecture 2. Componnet of master and its role for each 3. Component of worker and its role for each....

Vijay Chakravarthy G — Tue, 18 Oct 2022 06:41:03 +0000

Kubernetes Architecture: Kubernetes cluster has master nodes and worker nodes. Master node is the in charge and the worker nodes do the actual work.
Components of master are api-server, cluster store, controller-manager, scheduler.
apiserver is the front-end to the control plane and it exposes the API(REST) and consumes JSON via manifest files
Cluster store is the persistent storage which has the information about cluster state and configuration
Controller-manager is a node controller and watches for changes and helps maintain desired state.
Scheduler watches apiserver for new pods. It assigns work to nodes.
Components of worker node: The components of worker are Kubelet, container engine and kube-proxy.
Kubelet is the main kubernets agent. It registers nodes with clusters and watches apiserver. It instantiates pods and reports back to master.
Container engine does container management like pulling images, starting/stopping containers and etc..
Kube-proxy handles networking part w.r.t Pod IP addresses and load balances across all pods in a service.

What is 10 major problem solve by Kubernetes?

Vijay Chakravarthy G — Tue, 18 Oct 2022 04:49:10 +0000

1) Containers bring scalability challenges due to large in number. Kubernetes solves container scalability issues by managing the multiple hosts running containers
2) Kubernetes maintains the desired state by self healing
3) Kubernetes enhances productivity by decreasing the number of dependency errors
4)Container orchestration allows users to scale applications with Helmsman, one man can manage through Kubernetes
5) work load deployments are faster and simple
6) Security improvement through application isolation by separating applications in to deferent containers
7)Kubernetes provides load balancing of workloads
8)Kubernetes has the ability to absorb the changes quickly

Assignment

Vijay Chakravarthy G — Mon, 17 Oct 2022 07:36:26 +0000

What is difference between docker kill and docker stop? "docker stop" stops the running containers gracefully. It exits with a code 0.

"docker kill" stop the running containers abruptly. The container exists with a code 137.

4db69d6b08de httpd "httpd-foreground" 11 minutes ago Exited (137) 7 minutes ago dazzling_mclaren
bce0e2162489 httpd "httpd-foreground" 12 minutes ago Exited (0) 8 minutes ago raj

What is difference between docker pause and docker unpause? "docker pause" command suspends all processes in the specified containers. On Linux, this uses the freezer cgroup.

"docker unpause" command un-suspends all processes in the specified containers. On Linux, it does this using the freezer cgroup