Update Structure and added IaC codes

Days/day56.md

@@ -0,0 +1,135 @@
+## Understanding Infrastructure as a Code aka IaC and Terraform Basics
+
+An Infrastructure in common language would be considered as the final output obtained after processing multiple different kinds of inputs. </br>
+
+For instance: An Infrastructure for a car mainly includes Wheels, Engine, Steering, Clutch, brake, Accelerator and so on. </br>
+
+In similar way, for creating a cloud infrastructure, there is also some of its main building blocks,</br>
+
+
+# What is terraform? </br>
+
+Terraform is an infrastructure as code (IaC) tool that allows you to build, change and version infrastructure safely and efficiently. </br>
+This includes low-level components such as compute instances, storage, and networking, as well as high-level components such as DNS entries, SaaS features, etc. </br>
+- Terraform can manage both existing service providers and custom in-house solutions. 
+- For writing configuration in terraform we use HCL.
+- Hashicorp Configuration language (HCL)
+- HCL is a toolkit for creating structured configuration languages that are both human and machine-friendly, for use with command-line tools.
+- Although intended to be generally useful, it is primarily targeted towards devops tools, servers, etc.
+
+#### A simple HCL code would look something like this,
+
+```
+terraform {
+  required_providers {
+    aws = {
+      source  = "hashicorp/aws"
+      version = "~> 3.27"
+    }
+  }
+  required_version = ">= 0.14.9"
+}
+provider "aws" {
+  profile = "default"
+  region  = "us-west-2"
+}
+resource "aws_instance" "app_server" {
+  ami           = "ami-830c94e3"
+  instance_type = "t2.micro"
+
+  tags = {
+    Name = "MyFirstTerraformConfiguration"
+  }
+}
+```
+
+#### Key Components of Cloud Infrastructure
+- Compute
+
+Compute services are for running diverse workloads on the AWS Compute platform.
+Most importantly it helps to lower the infrastructure costs and accelerate innovation on the world’s most reliable, secure, and capable cloud.
+
+We are mainly going to use EC2 services in our upcoming blogs.
+
+- EC2
+
+Amazon Elastic Compute Cloud (Amazon EC2) is a web service that provides secure, resizable compute capacity in the cloud. It is designed to make web-scale computing easier for developers.
+resource "aws_instance" "example" {
+  ami           = var.AMIS[var.AWS_REGION]
+  instance_type = "t2.micro"
+}
+
+- Network and Content Delivery
+Use cases for Network and Content Delivery </br>
+
+- Networking foundations : It helps us to quickly set up, secure, and monitor our network.
+- Application networking : Provides traditional and modern applications with improved security, availability, performance, and streamlined monitoring.
+- Edge networking : Deliver your data with single-digit millisecond latency.
+- Hybrid connectivity : Create fast, secure, and reliable connections between your on-premises and AWS networks.
+
+
+We are mainly going to use VPC services in our upcoming blogs. </br>
+
+- VPC
+VPC stands for Virtual Private Cloud, using VPC we define and provision a logically isolated network for our AWS resources.
+```
+resource "aws_vpc" "main" {
+  cidr_block           = "10.0.0.0/16"
+  instance_tenancy     = "default"
+  enable_dns_support   = "true"
+  enable_dns_hostnames = "true"
+  enable_classiclink   = "false"
+  tags = {
+    Name = "main"
+  }
+}
+```
+
+- Storage
+
+Storage is a complete range of services for us to store, access, govern, and analyse our data to reduce costs, increase agility, and accelerate innovation.
+With using cloud storage we can reduce the storage costs.
+
+- S3
+
+Amazon Simple Storage Service (Amazon S3) is an object storage service that offers industry-leading scalability, data availability, security, and performance. </br>
+```
+ resource "aws_s3_bucket" "b" {
+  bucket = "nitin1455"
+}
+```
+
+- Security, Identity and Compliance
+Security, Identity and Compliance are for securing our workloads and applications in the cloud. </br>
+
+#### Some of it’s use cases are :
+
+- Data protection
+- Identity & access management
+- Network & application protection
+- Threat detection & continuous monitoring
+- Compliance & data privacy
+
+- IAM
+
+IAM is for securely managing access to services and resources.
+
+Using IAM, we can create and manage AWS users and groups, and use permissions to allow and deny their access to AWS resources.
+```
+resource "aws_iam_group" "administrators" {
+  name = "administrators"
+}
+```
+```
+resource "aws_iam_policy_attachment" "administrators-attach" {
+  name       = "administrators-attach"
+  groups     = [aws_iam_group.administrators.name]
+  policy_arn = "arn:aws:iam::aws:policy/AdministratorAccess"
+}
+```
+# user
+```
+resource "aws_iam_user" "admin1" {
+  name = "admin1"
+}
+```

Tools/8.IaC/Tarraform/README.md

@@ -0,0 +1,25 @@
+# TerratestWithTerraform
+
+Terratest is a Go library developed at Gruntwork, that makes it easier to write automated tests for our infrastructure code. It provides a variety of helper functions and patterns for common infrastructure testing tasks but here we will be discussing about Testing Terraform code.
+
+# To Run this application
+* git clone https://github.com/imnitin28/terra-form-test-techhub.git  <br />
+* cd test  <br />
+* go mod init "<MODULE_NAME>"  <br />
+* **MODULE_NAME would be github.com/<YOUR_USERNAME>/<YOUR_REPO_NAME>**  <br />
+* go mod init github.com/imnitin28/terra-form-test-techhub  <br />
+* go run
+
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------
+
+go mod init "<MODULE_NAME>" would create go.mod file into test folder.  <br />
+* The go.mod file is the root of dependency management in GoLang. 
+* All the modules which are needed or to be used in the project are maintained here in go.mod file.
+* It creates entry for all the packages we are going to use/import in our project.
+* It reduces effort for getting each dependencies manually.
+
+On running **go test** for the first time you would get go.sum file created.
+* go.sum file is created when **go test** or **go build** is executed for the first time.
+* It installs all the packages with specific version(latest)
+* we do not need to edit or modify this file.
+

Tools/8.IaC/Tarraform/awsResource/instance.tf

@@ -0,0 +1,12 @@
+resource "aws_instance" "example" {
+  ami           = var.AMIS[var.AWS_REGION]
+  instance_type = "t2.micro"
+  vpc_security_group_ids = [aws_security_group.instance.id]
+
+  # When the instance boots, start a web server on port 8080 that responds with "Hello, World!".
+  user_data = <<EOF
+#!/bin/bash
+echo "Hello, World!" > index.html
+nohup busybox httpd -f -p 8080 &
+EOF
+}

Tools/8.IaC/Tarraform/awsResource/output.tf

@@ -0,0 +1,4 @@
+# Output the instance's public IP address.
+output "public_ip" {
+  value = aws_instance.example.public_ip
+}

Tools/8.IaC/Tarraform/awsResource/provider.tf

@@ -0,0 +1,6 @@
+provider "aws" {
+  access_key = var.AWS_ACCESS_KEY
+  secret_key = var.AWS_SECRET_KEY
+  region     = var.AWS_REGION
+}
+

Tools/8.IaC/Tarraform/awsResource/securitygroup.tf

@@ -0,0 +1,9 @@
+# Allow the instance to receive requests on port 8080.
+resource "aws_security_group" "instance" {
+  ingress {
+    from_port   = 8080
+    to_port     = 8080
+    protocol    = "tcp"
+    cidr_blocks = ["0.0.0.0/0"]
+  }
+}

Tools/8.IaC/Tarraform/awsResource/terraform.tfvars

@@ -0,0 +1,3 @@
+AWS_ACCESS_KEY = "XXXX"
+AWS_SECRET_KEY = "XXXXXXXX"
+AWS_REGION="ap-south-1"

Tools/8.IaC/Tarraform/awsResource/vars.tf

@@ -0,0 +1,17 @@
+variable "AWS_ACCESS_KEY" {
+}
+
+variable "AWS_SECRET_KEY" {
+}
+
+variable "AWS_REGION" {
+  default = "ap-south-1"
+}
+
+variable "AMIS" {
+  type = map(string)
+  default = {
+    ap-south-1 = "ami-0860c9429baba6ad2"
+  }
+}
+

Tools/8.IaC/Tarraform/awsResource/versions.tf

@@ -0,0 +1,3 @@
+terraform {
+  required_version = ">= 0.12.26"
+}

Tools/8.IaC/Tarraform/test/terraform_test.go

@@ -0,0 +1,34 @@
+package test
+
+import (
+	"fmt"
+	"testing"
+	"time"
+
+	http_helper "github.com/gruntwork-io/terratest/modules/http-helper"
+
+	"github.com/gruntwork-io/terratest/modules/terraform"
+)
+
+func TestTerraformAwsHelloWorldExample(t *testing.T) {
+	t.Parallel()
+
+	/*Construct the terraform options with default retryable errors to handle the most common retryable errors in terraform testing. */
+	terraformOptions := terraform.WithDefaultRetryableErrors(t, &terraform.Options{
+		/* The path to where our Terraform code is located */
+		TerraformDir: "../awsResource",
+	})
+
+	/* At the end of the test, run `terraform destroy` to clean up any resources that were created.*/
+	defer terraform.Destroy(t, terraformOptions)
+
+	/* Run `terraform init` and `terraform apply`. Fail the test if there are any errors. */
+	terraform.InitAndApply(t, terraformOptions)
+
+	/* Run `terraform output` to get the IP of the instance */
+	publicIp := terraform.Output(t, terraformOptions, "public_ip")
+
+	/* Make an HTTP request to the instance and make sure we get back a 200 OK with the body "Hello, World!" */
+	url := fmt.Sprintf("http://%s:8080", publicIp)
+	http_helper.HttpGetWithRetry(t, url, nil, 200, "Happy, Learnings!", 30, 5*time.Second)
+}