This document discusses continuous deployment to Kubernetes. It defines common terms like deployment, containerization, orchestration and configuration management. It then outlines the typical DevOps lifecycle for provisioning infrastructure, configuring applications, and deploying applications. The document explains why Docker and Kubernetes are useful for building containerized applications and deploying them. It also describes how to build a continuous deployment pipeline for Kubernetes using tools like Helm to package and deploy applications as charts, and Argo to automate deployments through a GitOps workflow of committing manifests to a Git repository and having Argo deploy the latest versions.

1. Continuous Deployment using Kubernetes
by Arun Veeramani
DevOps & AI - Product Engineer
Cognizant Accelerator – Cognizant Product Division

2. Few JARGONS to be familiar with
Definition Tools popularly used
Deployment • It is the process of putting a new application, or new version of an application,
onto a prepared application server
Containerization • It is the process of bundling up the application code along with the environment
needed for it to execute the code
• It is a one time Job
Docker, Vagrant
Provisioning • It is the process of creating the infrastructure or the servers themselves, usually
called ‘Infrastructure as Code’
• It is a one time Job
Terraform, CloudFormation
Container
Orchestration
• It is the process of arranging and coordinating multiple containers across a
cluster of servers as per the resource crunch
• It is a one time Job to Install the application and are then managed
automatically by the cluster
Kubernetes, Docker Swarm
Configuration
Management
• It is a process of installing and managing software on the existing servers
• It is a one time job to install the application
Chef, Puppet, Ansible, and
SaltStack
Package Manager • A package manager or package management system is a collection of software
tools that automate the process of installing, upgrading, configuring, and
removing computer programs for a computer's operating system in a consistent
manner
Helm, Ksonnet

3. The DevOps Lifecycle
https://www.oreilly.com/library/view/devops-for-web/9781786465702/ch01s02.html

4. Infrastructure
Provisioning
•Terraform
Application Provisioning
& Configuration
Management
•Ansible
•Chef
•Puppet
Application Deployment
& Orchestration
•Ansible
•Chef
•Puppet
Infrastructure
Provisioning
•Terraform
Application Provisioning
& Configuration
Management using
CONTAINERS & VMs
•Docker
•Vagrant + Packer
Application Deployment
& Orchestration
•Kubernetes
•Docker Swarm
Note:
• Vagrant: Tool for building VMs for Development Environment
• Vagrant Box: Base Images for Vagrant
• Packer: Tool for building Machine Images, can create Vagrant Boxes
• Docker: Tool for building Containers for Applications & Environments
• Terraform: Infrastructure as Code
Why Docker & Kubernetes? - The Workflow

5. Kubernetes is beyond Comparison
Support for Microservices Framework – Service Discover & Load Balancing
Horizontal Scaling – Automatically based on CPU
Self-Healing – Restarting or Rescheduling Containers that don’t respond
Batch Job Execution
Secret and Configuration Management
Continuous Delivery – Automated Rollouts and Rollbacks
Ingress – Manage external access to the Services in the Cluster (API Gateway)
Kubernetes is more of a
Framework to build any
Platform, rather than
just a tool for Continuous
Deployment

6. Building a CD pipeline for Kubernetes
A typical flow for Deploying
any new Application into
Kubernetes involves
• Package your application into a Docker Image
• Upload the Docker Image to a Container Registry (Harbor)
• Deploy your Application (YAML) to the Cluster
• Expose your Application as a Service
The problems that arises with
the above flow includes
• Deploying Large Scale Applications with Release Management
• Managing Deployment strategy across Team Members working on the same Deployment
• Managing Rollbacks of new and old Deployments
• Maintaining different versions of YAMLs for the same Application
The solution to such problems
involves “Automated
Management of the
Deployment Workflow”
• Using Package Manger like HELM to deploy Applications using Charts
• Using Workflow Engine like ARGO to deploy Applications as a Sequence of tasks
• Using Package Manager like KSONNET to deploy Applications as a JSON Manifests

7. Continuous Deployment using HELM
Install Helm
Define a Helm
Chart
Package the
Chart
Deploy the
Release
Upgrade /
Rollback / Delete
a Release
https://www.slideshare.net/AdnanAbdulhussein/kubernetes-cicd-with-helm

8. Continuous Deployment using ARGO CI/CD
Install
ArgoProject
Specify a Git
Repository as a
SOT for defining
Desired
Application State
(GitOps)
Commit your
Kubernetes
Manifest using
Helm Charts /
YAML in your Git
Repository
Run a CI Pipeline to
build and push you
Image into your
Image Repo using
ARGO CI / Jenkins
Run a CD Pipeline
to deploy your
Manifests into the
Environment
specified using
ARGO CD
https://argoproj.github.io/docs/argo-cd/readme.html