https://DevOpsCloud.io -- Cloud Monk Losang Jinpa

Kubernetes

Kubernetes, often abbreviated as K8s, is an open-source container orchestration platform that automates the deployment, scaling, and management of containerized applications. It provides a declarative approach to managing containerized workloads, allowing you to define the desired state of your application and Kubernetes will handle the rest.

Key Features

**Container Orchestration:** Kubernetes schedules and manages the lifecycle of containers across a cluster of machines, ensuring they run efficiently and reliably.
**Declarative Configuration:** You define the desired state of your application using YAML manifests, and Kubernetes handles the orchestration to achieve that state.
**Scalability:** Kubernetes can automatically scale your applications up or down based on demand, ensuring they can handle varying workloads.
**Self-Healing:** It actively monitors the health of your applications and can restart or replace containers that fail, improving resilience and uptime.
**Service Discovery and Load Balancing:** Kubernetes provides mechanisms for service discovery and load balancing, enabling seamless communication between microservices within the cluster.
**Storage Orchestration:** It integrates with various storage providers, allowing you to dynamically provision and manage persistent storage for your applications.
**Extensibility:** Kubernetes offers a rich ecosystem of plugins and extensions, enabling you to customize and enhance its functionality.

Benefits

**Portability:** Kubernetes abstracts away the underlying infrastructure, allowing you to deploy your applications on various cloud providers or on-premises environments.
**Scalability:** Kubernetes automatically scales your applications to meet demand, ensuring optimal performance and resource utilization.
**High Availability:** Its self-healing mechanisms ensure that your applications remain available even in the face of failures.
**Efficiency:** Kubernetes optimizes resource utilization by efficiently scheduling containers and managing their lifecycle.
**Flexibility:** It supports various workload types, including stateless and stateful applications, batch jobs, and more.

Code Examples

1. **Deployment Manifest:**

```yaml apiVersion: apps/v1 kind: Deployment metadata:

 name: my-app

spec:

 replicas: 3
 selector:
   matchLabels:
     app: my-app
 template:
   metadata:
     labels:
       app: my-app
   spec:
     containers:
     - name: my-app
       image: my-org/my-app:latest
       ports:
       - containerPort: 8080

```

This manifest defines a Deployment for the “my-app” application, running 3 replicas of the specified container image.

2. **Service Manifest:**

```yaml apiVersion: v1 kind: Service metadata:

 name: my-service

spec:

 selector:
   app: my-app
 ports:
 - protocol: TCP
   port: 80
   targetPort: 8080

```

This manifest defines a Service that exposes the “my-app” pods on port 80, providing internal load balancing and service discovery.

3. **Ingress Manifest:**

```yaml apiVersion: networking.k8s.io/v1 kind: Ingress metadata:

 name: my-ingress

spec:

 rules:
 - http:
     paths:
     - path: /
       pathType: Prefix
       backend:
         service:
           name: my-service
           port:
             number: 80

```

This manifest defines an Ingress resource that routes external traffic to the “my-service” Service.

Additional Resources

**Kubernetes Official Website:** s://kubernetes.io/(https://kubernetes.io/)
**Kubernetes Documentation:** s://kubernetes.io/docs/(https://kubernetes.io/docs/)

“Kubernetes is an open source system for managing containerized applications (https://kubernetes.io/docs/concepts/overview/what-is-kubernetes) across multiple hosts; providing basic mechanisms for container deployment, container maintenance, and container scaling of applications.”

“Kubernetes builds upon a decade and a half of experience at Google running production workloads at scale using a system called Borg, combined with best-of-breed ideas and practices from the community.”

“Kubernetes is hosted by the Cloud Native Computing Foundation (CNCF - https://cncf.io). If you are a company that wants to help shape the evolution of technologies that are container-packaged, dynamically-scheduled and microservices-oriented, consider joining the CNCF. For details about who's involved and how Kubernetes plays a role, read the CNCF announcement”: https://www.cncf.io/announcement/2015/06/21/new-cloud-native-computing-foundation-to-drive-alignment-among-container-technologies

Fair Use Source: https://github.com/kubernetes/kubernetes

Video Courses

S304 - Creating a CI/CD Pipeline for Kubernetes Using Azure DevOps - Christian Meléndez

“Do you want to know how can you do Kubernetes deployments to a k8s cluster within minutes using VSTS? We'll start by simulating a common scenario of creating an app locally and deploy it to k8s. We'll enable CI/CD using VSTS and we'll use the exact same scripts we used locally. We'll connect VSTS with AKS.”