Ansible Vs Terraform - What is the difference between Ansible and Terraform - Ansible Vs Terraform

This is one of the common DevOps interview questions. What is the difference between Ansible and Terraform? When will you choose Ansible over Terraform?

Factor	Ansible	Terraform
Type	Configuration mgmt	Provisioning
Infrastructure	mutable	Immutable
Language	Procedural	Declarative
Written in	Python	Go
Architecture	client only	client only
State Management	No	Yes
Cloud	All	All
Syntax	YAML	JSON
UI/CLI	Has both UI(Ansible Tower) and CLI	only CLI based

Jenkins Terraform Integration | How do you integrate Terraform with Jenkins | Automate Infrastructure setup using Terraform and Jenkins

We will be learning how to execute Terraform scripts automatically using Jenkins pipeline. We will create EC2 instance using Terraform and Jenkins in AWS cloud.

Pre-requisties:

• Jenkins is up and running
• Terraform is installed in Jenkins
• Terraform files already created in your SCM.

I have provided my public repo as an example which you can use.

Create IAM role to provision EC2 instance in AWS 

Select AWS service, EC2, Click on Next Permissions

Type EC2 and choose AmazonEC2FullAccess as policy

Click on Next tags, Next Review

give some role name and click on Create role.

Assign IAM role to EC2 instance

Go back to Jenkins EC2 instance, click on EC2 instance, Security, Modify IAM role

Type your IAM role name my-ec2-terraform-role and Save to attach that role to EC2 instance.

Create Jenkins Pipeline 

Add parameters to the pipeline

Click checkbox - This project is parameterized, choose Choice Parameter

Add name as action

type apply and enter and type destroy as choices as it is shown below

Go to Pipeline section

Add below pipeline code

pipeline {

    agent any

    stages {

        stage('Checkout') {

            steps {

            checkout([$class: 'GitSCM', branches: [[name: '*/main']], extensions: [], userRemoteConfigs: [[url: 'https://github.com/mydevopscoach/my-tf-iac-aws-repo']]])            

          }

        }

        

        stage ("terraform init") {

            steps {

                sh ('terraform init') 

            }

        }

        

        stage ("terraform Action") {

            steps {

                echo "Terraform action is --> ${action}"

                sh ('terraform ${action} --auto-approve') 

           }

        }

        

    }

}

Click on Build with Parameters and choose apply to build the infrastructure or choose destroy if you like to destroy the infrastructure you have built. 

Click on Build

Now you should see the console output if you choose apply.

Pipeline will look like below:

Login to AWS console, you should see the new EC2 instance created.

How to Integrate Jenkins and GitHub using SSH keys? | Jenkins and GitHub Integration

We will see how to connect to GitHub from Jenkins using SSH keys instead of using user name and password. It is also a good practice to use SSH keys in Jenkins jobs instead of using user name and password.

Watch the steps in YouTube channel:

Pre-requistes:

• Jenkins is up and running
• Credentials plug-in installed in Jenkins

Create SSH keys in your Jenkins EC2 instance

ssh-keygen

enter four times. this will create keys in .ssh folder.

Copy and paste the public key

sudo cat ~/.ssh/id_rsa.pub

Add public Keys into your respective GitHub

Add public keys into your Repository--> settings--> Deploy keys section

Click on Add Deploy Key and enter public keys and save.

Add Private Keys in Jenkins Master

Login Jenkins. Go to Manage Jenkins. click on Credentials

Click on Jenkins

Click on Global Credentials

Click on Add Credentials

Choose SSH username with private key

Choose SSH username with private key
username can be anything
Click on enter directly under private key option and Click Add

Copy and paste private key(not public key) of your from Jenkins instance. command is below:
sudo cat ~/.ssh/id_rsa

copy the content of whole output from above command.

Click OK to save.

Now go to any Jenkins Job, you can choose this option for checking out from GitHub. Make sure you enter SSH url not https url.

That's it. This is how you use SSH url and private keys to checkout code from bitbucket or Github without entering username/password in Jenkins.

How to create Azure Container Registry using Terraform in Azure Cloud | Setup Azure Container Registry using Terraform

Hashicorp's Terraform is an open-source tool for provisioning and managing cloud infrastructure. Terraform can provision resources on any cloud platform. 

Terraform allows you to create infrastructure in configuration files(tf files) that describe the topology of cloud resources. These resources include virtual machines, storage accounts, and networking interfaces. The Terraform CLI provides a simple mechanism to deploy and version the configuration files to Azure.

Watch the steps in YouTube:

Advantages of using Terraform:

• Reduce manual human errors while deploying and managing infrastructure.
• Deploys the same template multiple times to create identical development, test, and production environments.
• Reduces the cost of development and test environments by creating them on-demand.

How to Authenticate with Azure?

Terraform can authenticate with Azure in many ways, in this example we will use Azure CLI to authenticate with Azure and then we will create resources using Terraform.

Pre-requisites:

Azure CLI needs to be installed.

Terraform needs to be installed.

Logging into the Azure CLI

Login to the Azure CLI using:

az login

The above command will open the browser and will ask your Microsoft account details. Once you logged in, you can see the account info by executing below command:

az account list

Now create a directory to store Terraform files.

mkdir tf-acr

cd tf-acr

Let's create a terraform file to use azure provider. To configure Terraform to use the Default Subscription defined in the Azure CLI, use the below cod.

Now initialize the working directory

sudo vi create-acr.tf

provider "azurerm" {
  features {}
}
resource "azurerm_resource_group" "rg" {
  name     = "rg-tf-acr"
  location = "southcentralus"
}
resource "azurerm_container_registry" "acr" {
  name                     = "azcontainerregistry321"
  resource_group_name      = azurerm_resource_group.rg.name
  location                 = azurerm_resource_group.rg.location
  sku                      = "Basic"
  admin_enabled            = true
}
output "admin_password" {
  value       = azurerm_container_registry.acr.admin_password
  description = "The object ID of the user"
sensitive = true
}

Perform the below command to initialize the directory.

terraform init

Once directory is initialized, you can start writing code for setting up the infrastructure. Now Perform the below command to validate terraform files.

terraform validate

perform plan command to see how many resources will be created.

terraform plan

terraform apply

Do you want to perform these actions?

type yes 

Now Login into Azure Cloud to see the resources created.

How to destroy the resources ?

Execute terraform destroy

The above command to destroy both resource group and container registry created before.

How to store Terraform state file in S3 Bucket | How to manage Terraform state in S3 Bucket?

One of the things that Terraform does (and does really well) is “tracks” your infrastructure that you provision. It does this through the means ofstate.

By default, Terraform stores state locally in a file named terraform.tfstate. This does not work well in a team environment where if any developer wants to make a change he needs to make sure nobody else is updating terraform in the same time.

Why state file should not be stored in your local machine?

• Local state doesn't work well in a team or collaborative environment.
• Terraform state can include sensitive information.
• Storing state locally increases the chance of inadvertent deletion.

With remote state, Terraform writes the state data to a remote data store, which can then be shared between all members of a team. Terraform supports storing state in many ways including the below:

• Terraform Cloud
• HashiCorp Consul
• Amazon S3
• Azure Blob Storage
• Google Cloud Storage
• Alibaba Cloud OSS
• Artifactory or Nexus 

We will learn how to store state file in AWS S3 bucket. We will be creating S3 bucket and also create Dynamo Table where we will be storing lock.

Watch the steps in YouTube Channel:

Pre-requistes:

• Make sure Terraform is setup. I am using Ubuntu 18.0.4
  
• Install AWS CLI
  
• AWS access keys and secret keys have been configured using AWS CLI.
  

Steps:

mkdir project-terraform

cd project-terraform

First let us create necessary terraform files.

Create tf files

sudo vi variables.tf

variable "region" {
    default = "us-east-2"
}

variable "instance_type" {
    default = "t2.micro"
} 

sudo vi main.tf
provider "aws" {
  region     = "${var.region}"
}

#1 -this will create a S3 bucket in AWS
resource "aws_s3_bucket" "terraform_state_s3" {
  bucket = "terraform-coachdevops-state"
  force_destroy = true
# Enable versioning to see full revision history of our state files
  versioning {
         enabled = true
        }

# Enable server-side encryption by default
server_side_encryption_configuration {
    rule {
      apply_server_side_encryption_by_default {
        sse_algorithm = "AES256"
      }
    }
  }
}

# 2 - this Creates Dynamo Table
resource "aws_dynamodb_table" "terraform_locks" {
  name         = "tf-up-and-run-locks"
  billing_mode = "PAY_PER_REQUEST"
  hash_key     = "LockID"
        attribute {
         name = "LockID"
         type = "S"
      }
}

now let us initialize terraform.

terraform init

terraform apply

 

this will create two resources - S3 bucket and AWS Dynamo table. But still terraform state file is stored locally. if you type below command, you will see the tfstate file locally.

 ls -al

To store state file remotely, you need to add following code with terraform block. This will add backend configuration.

sudo vi main.tf

#Step 3 - Creates S3 backend
terraform {
  backend "s3" {
    #Replace this with your bucket name!
    bucket         = "terraform-coachdevops-state"
    key            = "dc/s3/terraform.tfstate"
    region         = "us-east-2"
    #Replace this with your DynamoDB table name!
    dynamodb_table = "tf-up-and-run-locks"
    encrypt        = true
    }
}

terraform init

and then type yes and enter. Now you see local state file has 0 bytes(empty)

Now login to AWS console, Click on S3, Click on the bucket name

Now you should be able to see tfstate file in S3.

Click on the terraform.tfstate file, you can see multiple version of your state file. Terraform is automatically pushing and pulling state data to and from S3.

How to perform Destroy?

It is not that straight forward as back end is referencing S3 bucket, if we delete S3 bucket, back end will not where to reference. So we need to perform below steps to perform destroy:

1. remove back end reference in the main.tf by commenting out backend section of the code.

sudo vi main.tf

remove the below code or comment out:

/*

terraform {
  backend "s3" {
    #Replace this with your bucket name!
    bucket         = "terraform-coachdevops-state"
    key            = "dc/s3/terraform.tfstate"
    region         = "us-east-2"
    #Replace this with your DynamoDB table name!
    dynamodb_table = "tf-up-and-run-locks"
    encrypt        = true
    }
}

*/

We need to initialize again. so type below command

terraform init -migrate-state

type yes

Now you will see the local state file have been updated.

Now perform you can delete all the resources created by Terraform including S3 bucket and Dynamo table.

terraform destroy

Install Azure CLI in Ubuntu 22.0.4 | How to setup Azure CLI in Ubuntu 20.0.4 | How to Install Azure CLI in Ubuntu

The Azure command-line interface (Azure CLI) is a set of commands used to create and manage Azure resources. The Azure CLI is available across Azure services and is designed to get you working quickly with Azure, with an emphasis on automation. Azure CLI is Microsoft's cross-platform command-line experience for managing Azure resources.

Azure CLI can be installed by executing the below command:

curl -sL https://aka.ms/InstallAzureCLIDeb | sudo bash

Once Azure CLI is installed, you can verify it by executing below command:

az version