Kubernetes Introduction for Beginners

Have you heard about Kubernetes and how it makes deploying applications easier? If you want to learn what Kubernetes is all about and get started with container orchestration, then this comprehensive beginner‘s guide is for you! I‘ll provide key concepts and practical advice to help you on your Kubernetes journey.

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Why Read This Kubernetes Introduction?

Over the last few years, Kubernetes has rapidly become the go-to platform for deploying containerized workloads. As per recent reports:

  • 94% of professionals running containers now leverage Kubernetes for orchestration
  • Cloud native architectures could make up 95% of new deployments within 5 years

But what drove this widespread adoption and why has Kubernetes become so popular?

In essence, Kubernetes makes running containerized apps across endless infrastructure seamless.

It handles critical management tasks like:

  • Automated deployment and scaling
  • Balancing resource usage
  • Ensuring high availability
  • Simplified rollouts and rollbacks

As companies shift towards breaking apart monoliths into microservices and cloud native designs, Kubernetes empowers them to adopt these patterns efficiently.

The rest of this guide will provide Kubernetes beginners with:

  • Common terminology demystified
  • Options for running Kubernetes clusters
  • Step-by-step workflow for deploying apps
  • Tips for monitoring and managing deployments
  • …and more!

Let‘s get you on the fastest path towards leveraging Kubernetes by covering all the essentials.

What is Kubernetes?

At the most basic level, Kubernetes acts as an orchestrator between infrastructure, developers and applications. It takes away enormous operational complexity when working with containers.

Here are some key components and capabilities:

  • Clusters and Nodes – Kubernetens provides a production-grade platform to run containers, abstracting away low level infrastructure details.
  • Pods and Services – These abstractions simplify networking, storage, release management for apps.
  • Controllers and Scheduling – Automates operational tasks like scaling pods, rolling updates, failovers.
  • CLI and Dashboards – Interface for managing the state of the entire system.

Translating these concepts into real world examples makes them more intuitive:

  • Nodes = Servers – The VMs or bare metal machines Kubernetes runs on.
  • Pods = Containers – Single units of deployment encapsulating containers.
  • Services = Traffic Load Balancers – Networking logic + DNS to access pods.
  • Controllers = Automation Bot – Self-healing and keeping applications stable.

With Kubernetes handling this complexity behind the scenes, developers are free to focus building application logic. It massively boosts their productivity and iteration speed.

Let‘s now dive deeper into some core Kubernetes concepts that form key building blocks. Grasping these will provide foundational knowledge as you get started.

Kubernetes Concepts Explained

While containers package up applications into standard units, additional orchestration is needed to effectively manage containers in production.

This is the problem Kubernetes tackles with its own abstractions.

Here are some central ideas and components:

Pods

The smallest units that can be created, scheduled and managed on Kubernetes. Pods represent single processes running on cluster nodes.

  • Encapsulates containers that make up a logical application.
  • Containers inside share networking, storage, specifications.
  • New containers can be added to pods for helper utilities.

Services

An abstraction that provides networking access to one or more pods as logical sets.

  • Single stable entry point to access pods using DNS naming.
  • Load balances network traffic across multiple pod instances.
  • Handles release management for long running applications.

Deployments

A Kubernetes controller that allows declaring the intended state for pods and containers. It focuses on deployment strategies and lifecycle management for pod replicas.

Key responsibilities include:

  • Declare the number of pod replicas needed
  • Scale number of pods up or down
  • Automate container restarts on failures
  • Manage rolling updates to minimize downtime

Additionally, Kubernetes has concepts like:

  • Namespaces – Used to create virtual clusters and divide compute resources.
  • Volumes – Semi-permanent storage attached to pods enabling stateful apps like databases.
  • ConfigMaps – Externalizable configurations useful for injecting into services.
  • Ingress – Route external traffic to services based on URL rules as a reverse proxy.

Grasping these basics allows you to leverage Kubernetes abstractions instead of focusing lower level infrastructure or container details.

Next let‘s explore environments for running Kubernetes before deploying applications.

Setting Up Kubernetes Clusters

Now that we‘ve covered Kubernetes 101 concepts, the next step is setting up a cluster to run containers on. Here are common options:

Local Solutions

  • Minikube – Single node clusters for testing locally on Linux/Mac/Windows machines
  • Kind – Uses Docker containers as cluster nodes for learning purposes

On Premise Production Setups

  • kubeadm – Toolkit for installing vanilla upstream Kubernetes easily
  • Rancher k3s – Certified lightweight production distribution of K8s

Managed Cloud Solutions

  • AWS EKS – Amazon Elastic Kubernetes Service
  • Azure AKS – Azure Kubernetes Service
  • GCP GKE – Google Kubernetes Engine

Criteria to evaluate when picking a platform:

  • Environment type – dev, test, or production
  • Size and scalability needs
  • Hardware or budget limitations
  • Cloud vs on-premise restrictions
  • Organization‘s ecosystem preferences

For complete step-by-step instructions on installing Kubernetes across these environments, refer to detailed setup guides for Minikube, kubeadm, AWS EKS and other managed cloud services.

Deploying Applications on Kubernetes

Once your environment is ready, you can start deploying applications on Kubernetes by:

1. Containerizing Applications

First, package applications as Linux containers before managing them with Kubernetes:

  • Use Docker and Dockerfiles to build images
  • Leverage Buildpacks from Paketo, Heroku etc
  • Ensure containers follow best practices

2. Defining Kubernetes Resources

Declare required Kubernetes manifests in YAML or JSON:

  • Deployments
  • Services
  • Ingresses
  • PersistentVolumes
  • ConfigMaps

3. Pushing Images to Registry

Push images to a container registry for deployment:

  • Public hubs like Docker Hub
  • AWS Elastic Container Registry
  • Google Container Registry
  • Azure Container Registry

4. Deploying Resources

Finally, tell Kubernetes to deploy application resources:

kubectl apply -f ./my-app

Additional best practices for streamlined workflows:

  • Use Helm to package apps and parameterize deployments
  • Follow Infrastructure-as-Code patterns with Terraform
  • Enable CI/CD pipelining with GitOps workflows
  • Monitor metrics and logs with aggregation tools

Adopting standardized patterns upfront prevents future headaches at scale.

Day 2: Managing Apps on Kubernetes

Beyond just launching apps, Kubernetes simplifies critical day-2 operations:

Monitoring and Logging

  • Surface insights into performance, errors and logs
  • Detect outages before they cause damage
  • Aggregate metrics with Prometheus and Grafana

Auto Scaling Workloads

  • Automatically scale pods out and in based on demands
  • Optimally utilize provisioned resources

Blue/Green and Canary Deployments

  • Test changes incrementally before final rollout
  • Avoid downtime when shipping features

Self-Healing Capabilities

  • Kubernetes auto restarts failed containers
  • Reschedules pods if nodes go down
  • Ensures maximum application uptime

Efficient Resource Usage

  • Right size underlying node machines
  • Enable cluster auto-scaling capabilities
  • Schedule workloads intelligently

These operational tasks are vastly simplified through Kubernetes‘ cluster level abstractions compared to managing infrastructure directly.

Wrap Up & Next Steps

Congratulations on completing this extensive introduction to Kubernetes! We covered:

  • Kubernetes core concepts and architecture
  • Environment setup – local, cloud and on-prem options
  • Deploying containerized apps on Kubernetes
  • Post-deployment management best practices

You now have fundamental knowledge to start leveraging Kubernetes. Next recommended steps:

  • Follow quickstart guides to deploy sample apps
  • Get hands-on Kubernetes experience
  • Learn how to monitor, log and debug apps
  • Understand add-ons like Istio service mesh

The Kubernetes ecosystem is vast with incredible depth. Hopefully this beginner‘s guide provided a solid launch pad before going further. Feel free to reach out if you have any other questions on your Kubernetes journey!

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