OpenShift is a cloud development Platform as a Service (PaaS) hosted by Red Hat. It’s an open source cloud-based user-friendly platform used to create, test, and run applications, and finally deploy them on cloud. OpenShift is capable of managing applications written in different languages, such as Node.js, Ruby, Python, Perl, and Java. One of the key features of OpenShift is it is extensible, which helps the users support the application written in other languages.

Chef is a tool used for Configuration Management. Chef is an automation tool that provides a way to define infrastructure as code. Infrastructure as code simply means that managing infrastructure by writing code rather than using manual processes. It can also be termed as programmable infrastructure. Chef uses a pure-Ruby, domain-specific language for writing system configuration.

Advantages of Chef:

1. Accelerating Software Delivery
2. Increasing Service Resiliency
3. Improving Risk Management
4. Accelerating Cloud Adoption
5. Managing Both Data Center and Cloud Environments
6. Delivering All Your Infrastructure
7. Reduction of work time
8. Application to multiple servers at once
9. Reduction of operation cost
10. Redecoration of construction

Installation of chef workstation:

• wget https://packages.chef.io/files/stable/chef-workstation/22.5.923/el/7/chef-workstation-22.5.923-1.el7.x86_64.rpm

• ls
• rpm -ivh chef-workstation-22.5.923-1.el7.x86_64.rpm
• which chef
• ls /usr/bin/chef*
• chef version

Example program for recipe:

$ chef-apply filename.rb

In file.rb type:

file ‘/opt/first.txt’

file ‘/opt/first.txt’ do

action :delete

end

file ‘/opt/content.txt’ do

content “This is my first program of chef”

mode 755

owner root

end

httpd

create a index.html

copy index.htmkl

start

package ‘name’ do

package_name “httpd”

end

file ‘index.html’ do

content “<h1> Welcome to DevOpsSchool Chef Class</h1>”

end

bash ‘extract_module’ do

code <<-EOH

cp index.html /var/www/html/

EOH

end

service ‘httpd’ do

service_name “httpd”

action :start

end

Terraform is an open source “Infrastructure as Code” tool, created by HashiCorp. A declarative coding tool, Terraform enables developers to use a high-level configuration language called HCL (HashiCorp Configuration Language) to describe the desired “end-state” cloud or on-premises infrastructure for running an application. It then generates a plan for reaching that end-state and executes the plan to provision the infrastructure.

Example for Terraform Program:

provider “aws” {

region = “us-west-1”

}

resource “aws instance” myec2″ {

ami = “ami-12345qwert”

instance_type = “t2.micro”

}

Terraform Commands:

• Terraform apply : it executes the actions proposed in a terraform plan.
• Terraform plan :creates an execution plan, which let’s us to preview the changes that terraform plans to make to your infrastructure.
• Terraform init : it is used to initialize a working directory containing configuration files.
• Terraform destroy : terminates resources defined in terraform configuration.
• Terraform show :used to provide human readable output from a state or plan file.

Kubernetes is an open-source container – orchestration system for automating application deployment, scaling, and management. It was originally designed by Google, and is now maintained by the Cloud Native Computing Foundation. Kubernetes is also known as k8s or kube. Kubernetes was first developed by engineers at Google before being open sourced in 2014.

Reasons to use Kubernetes are:

1. Vendor-agnostic
2. Service discovery
3. Invocation
4. Elasticity
5. Resilience

Components of Kubernetes:

• Kubernetes Cluster: When we have Kubernetes set up on our systems, we get a cluster. A Cluster can be considered as a set of worker machines or VMs, called nodes, that would run the containerized applications. Every cluster node has at least a worker node in it and a manager node.
• Pods: The smallest unit of deployment of an application. It is ephemeral in nature.
• Worker nodes: The worker nodes are the worker machines or VMs host and runs the pods of the deployed workload on them.
• Workloads: The application-related deployment that needs to bind the services and other features to the application is configured by workload.
• Control Plane : The control plane manages the worker nodes, pods, and all the communication between the network and services.
• Node components: These components run actively on every node within the cluster to ensure the orchestration of the running pods and services.

Docker is a set of platform as a service (PaaS) products that use OS level virtualization to deliver software in packages called containers. The service has both free and premium tiers. The software that hosts the containers is called Docker Engine. Docker can package an application and its dependencies in a virtual container that can run on any Linux, Windows, or macOS computer. This enables the application to run in a variety of locations. Docker containers are lightweight, a single server or virtual machine can run several containers simultaneously.

Container:

A Docker container is a standardized, encapsulated environment that runs applications. A container is managed using the Docker API or CLI. Containers are an abstraction at the app layer that packages code and dependencies together. Multiple containers can run on the same machine and share the OS kernel with other containers, each running as isolated processes in user space. Containers take up less space than VMs  can handle more applications and require fewer VMs and Operating systems.

Advantages of Docker:

• Return on Investment and Cost Savings 
• Standardization and Productivity
• Continuous Deployment and Testing
• Compatibility and Maintainability
• Simplicity and Faster Configurations

Commands used:

curl -fsSL get.docker.com -o get-docker.sh
sudo sh get-docker.sh
sudo systemctl enable docker
sudo systemctl start docker
docker version
docker info

Installation of docker using above commands

docker images
docker pull httpd

docker ps -a
docker stop eed09d3f6193
docker ps -a
docker restart eed09d3f6193
docker ps -a
docker kill eed09d3f6193
docker ps -a
docker start eed09d3f6193
docker ps -a
docker pause eed09d3f6193
docker ps -a
docker unpause eed09d3f6193
docker ps -a
docker stop eed09d3f6193
docker ps -a
docker rm eed09d3f6193
docker ps -a

Pulling the image and performing operations like start, stop, pause, unpause, kill, remove using above commands.

Advantages of DevOps are:

1.Continuous Delivery

2.Innovation

3.Process Optimization

4.Fast Delivery

5.Correction of Defects

6.Digital Transformation

7.Collaboration

8.Quality

9. Visibility

10.Reduced Risk of Change

Tools we use in DevOps are:

-> Jenkins

-> Docker

-> Nagios

-> Ansible

-> GitHub

-> Bitbucket

-> Vagrant

-> Phantom

-> Slack

-> Sentry

Implementation of DevOps:

First we have to Organize DevOps Initiatives and then develop the strategy. Containerizing, Integrating Infrastructure automation with CI/CD tools. Increasing the amount of test automation and aligning QA with development and finally total application performance monitoring.