DevOps Classroom notes 13/Dec/2023

Scenario: Create a virtual Machine / EC2 instance

• Details:
  • Size:
    • CPU: 1 vcpu
    • RAM: 1 GB
  • Operating System: Redhat Linux
  • Disk: 10 GB
• Options:
  • Manual
  • Command Line
  • Templated

Infrastructure as Code (IaC)

• Infrastructure required for the application is expressed in a templated format with variables which can be passed dynamically
• IaC tries to maintain desired state expressed by user

Terraform

• Terraform is an on open source Infra Provisioining tool to create, manage and update infrastructure in various providers such as
  • AWS
  • Azure
  • GCP
  • AliCloud
  • Openstack
  • VM ware
• As part of CI/CD Pipeline we need to manage multipel environments for an application
  • Dev
  • QA
  • Staging
• Terraform can use the some template across various environments
  
• Terraform also allows parallel executions by multiple users across organizations.
• Alternatives to Terraform
  • ARM Templates, Azure Bicep
    • Can be used in Azure Only
  • AWS Cloud formation:
    • Can be used with AWS Only
  • Pulumi: As of now terraform is much popular than this.

Scenarios with Terraform in CI/CD

• If we categorize the infra managed by terraform we have 3 broader categories
  • Virtual Machines
  • Cloud Platforms
  • Kubernetes

Steps to Learn Terraform

• The template in terraform is expressed in Hashicorp Configuration Lanaguage (HCL).
• Terms:
  • Provider: Where we want to create resources.
  • resource: The individual infra element to be created
  • module: reusable template.
• WOW (Ways of Working)
  • Figure out manual steps
  • identify what can change and parametrize
  • Now each step try to use HCL