Infrastructure as a Code (IaC)

Categories

1. Ad hoc scripts

   • Shell script that makes calls to like AWS to provison 5 EC2 machines

2. Configuration management tools

   • Used on premis to manage config of servers

   • Ansible, puppet and chef are examples

3. Server Templating tools

   • Used for building out a template will be provisioned on a server

   • Examples are Amazon AMI

4. Orchestration tools

   • Kubernetes is an example

5. Provisioning tools

   • Used to provision cloud resources

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Declarative vs Imperative

Declarative

• We define end state of what we want

• Tool manages what API calls need to be made and it makes that happen

Imperative

• We tell system what we want to happen and the sequence in which we want to happen

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Cloud Specific vs Cloud Agnostic

Cloud Specific

• Examples are AWS Cloud Formation, Azure Resource Manager, Coogle Cloud Deployment Manager which focuses on particular cloud

Cloud Agnotic

• It does not focus on a simple platform. It is generic in nature

• Examples are Terraform and Pulumi

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Common Patterns

Provisioning + Config Management

We can use terraform with ansible, chef or puppet that will allow us to for instance setup a particular service once EC2 machine is deployed

Provisioning + Server Templating

Terraform can also be used with hashicorp packer which package the image and can be used later as an AMI

Provisioning + Orchestration

Terraform can be used with kubernetes cluster. Terraform is used to deploy cloud resources and k8 will be used to deploy the applications managed onto that cloud resource

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