Saturday, 6 March 2021

Terraform CD Pipeline Setup to Deploy App Servers

Overview

The goal is to implement Devops best practices to run Terraform in Jenkins Pipelines. We will go over the main concepts that need to be considered and a Jenkinsfile that runs Terraform. The Jenkinsfile will consists of parameters that allows us to pass data as variables in our pipeline job. 


  • Install Terraform on Jenkins Server
  • Install Terraform Plugin on Jenkins
  • Configure Terraform
  • Store and Encrypt Credentials in Jenkins
  • Setting up CD Pipeline with Terraform to Deploy App Servers
  • Run Pipeline Job


Install Terraform on Jenkins Server


Use the following commands to install Terraform on Jenkins server and move the binaries to the correct path as shown below.


  • wget https://releases.hashicorp.com/terraform/0.12.24/terraform_0.12.24_linux_amd64.zip
  • unzip terraform_0.12.24_linux_amd64.zip
  • sudo mv terraform /usr/bin/

Install Terraform plugin on Jenkins

Go to Manage Jenkins > Manage Plugins >Available > search Terraform as shown below:

As you can see, Terraform Plugin is already installed on my Jenkins hence why it's displayed in the Installed section.

Store and Encrypt Credentials in Jenkins (Access and Secret Key) 

In this step, we will be storing and encrypting the access and secret key in Jenkins to maximize security and minimize the chances of exposing our credentials.

    • Go to Manage Jenkins > Manage Credentials > Click on Jenkins the highlighted link as shown below


    • Select Add Credentials
    • Choose Secret text in the Kind field
    •  Enter the following below:
    Note: Modify the yellow highlighted text with the right value.
      • Secret = EnterYourSecretKeyHere
      • ID = AWS_SECRET_ACCESS_KEY
      • Description = AWS_SECRET_ACCESS_KEY
    Click OK

    Add another credential and enter the following:

      • Secret = EnterYourAccessIDHere
      • ID = AWS_ACCESS_KEY_ID
      • Description = AWS_ACCESS_KEY_ID

    Click OK





    Configure Terraform

    Go to Manage Jenkins > Global Tool Configuration > It will display Terraform on the list.

    • Enter terraform in the Name field
    • Provide the path /usr/bin/ as shown below




    Setting up CD Pipeline for Terraform

    • Go to Jenkins > New Items. Enter terraform-pipeline in name field > Choose Pipeline > Click OK


    • Select Configure after creation.
    • Go to Build Triggers and enable Trigger builds remotely.
    • Enter tf_token as Authentication Token

     

    Bitbucket Changes
      • Create a new Bitbucket Repo and call it terraform-pipeline
      • Go to Repository Settings after creation and select Webhooks
      • Click Add Webhooks
      • Enter tf_token as the Title
      • Copy and paste the url as shown below
                  http://JENKINS_URL:8080/job/terraform-pipeline//buildWithParameters?token=tf_token
      • Status should be active
      • Click on skip certificate verification
      • triggers --> repository push
    • Go back to Jenkins, select Pipeline Script From SCM
    • Enter credentials for Bitbucket, Leave the Branch as blank, Make sure script path is Jenkinsfile
    • Right click on Pipeline Syntax and open in a new tab. 
    • Choose Checkout from Version Control in the Sample Step field
    • Enter Bitbucket Repository URL and Credentials, leave the branches blank
    • Click GENERATE PIPELINE SCRIPT, copy credentialsId and url (This is required for Jenkinsfile script)



    Create Workspace for Terraform Pipeline
    • Open File Explorer, navigate to Desktop and create a folder cd_pipeline

    • Once folder has been created, open Visual Code Studio and add folder to workspace







    • Open the Terminal
    • Navigate to terraform-pipeline repo in Bitbucket
    • Run the command before cloning repo: git init
    • Clone the repo with SSH or HTTPS
    • Create a new file main.tf and copy the below code in yellow color


















    provider "aws" {

    region = var.region

    version = "~> 2.0"

    }

    resource "aws_instance" "ec2" {

    user_data   = base64encode(file("deploy.sh"))

    ami = "ami-0782e9ee97725263d"   ##Change AMI to meet OS requirement as needed.

    root_block_device {

        volume_type           = "gp2"

        volume_size           = 200

        delete_on_termination = true

        encrypted             = true

      }

    tags = {

    Name = "u2-${var.environment}-${var.application}"

    CreatedBy = var.launched_by

    Application = var.application

    OS = var.os

    Environment = var.environment

    }


    instance_type = var.instance_type


    key_name = "Enter_KEYPAIR_Name_Here"

    vpc_security_group_ids = [aws_security_group.ec2_SecurityGroups.id]

    }


    output "ec2_ip" {

    value = [aws_instance.ec2.*.private_ip]

    }

    output "ec2_ip_public" {

    value = [aws_instance.ec2.*.public_ip]

    }

    output "ec2_name" {

    value = [aws_instance.ec2.*.tags.Name]

    }

    output "ec2_instance_id" {

    value = aws_instance.ec2.*.id


    • Create a new file security.tf and copy the below code in yellow color

    resource "aws_security_group" "ec2_SecurityGroups" {
    name = "u2-${var.environment}-sg-${var.application}"
    description = "EC2 SG"
    ingress {
    from_port = 22
    to_port = 22
    protocol = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
    }
    ingress {
        from_port   = 8081
    to_port     = 8081
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
      }
    ingress {
         from_port   = 8082
    to_port     = 8082
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
       }
      ingress {
    from_port = 80
    to_port = 80
    protocol = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
    }
    #Allow all outbound
    egress {
    from_port = 0
    to_port = 0
    protocol = "-1"
    cidr_blocks = ["0.0.0.0/0"]
    }
    }

    • Create a new file variable.tf and copy the below code in yellow color. 

    variable region {

      type        = string

      default = "us-east-2"

    }

    variable "instance_type" {}

    variable "application" {}

    variable "environment" {}

    ############## tags

    variable os {

      type        = string

      default = "Ubuntu"

    }


    variable launched_by {

      type        = string

      default = "USER"

    }

    ############## end tags


    • Create a new file deploy.sh and copy the below code in yellow color. 
    #!/bin/bash
    set -x

    exec > >(tee /var/log/user-data.log|logger -t user-data -s 2>/dev/console) 2>&1 

    echo ""
    echo "........................................"
    echo "Installation of application"
    echo "........................................"
    echo "Today's date: `date`"
    echo "........................................"
    echo ""
    sudo pip install awscli
    sudo apt-get install -y unzip
    sudo apt update
    sudo apt dist-upgrade
    sudo apt autoremove
    sudo apt update
    sudo apt-get install openjdk-8-jdk openjdk-8-doc
    java -version
    sudo apt install wget software-properties-common
    sudo wget -qO - https://api.bintray.com/orgs/jfrog/keys/gpg/public.key | sudo apt-key add - 
    sudo add-apt-repository "deb [arch=amd64] https://jfrog.bintray.com/artifactory-debs $(lsb_release -cs) main"
    sudo apt update
    sudo apt install jfrog-artifactory-oss
    sudo systemctl stop artifactory.service
    sudo systemctl start artifactory.service
    sudo systemctl enable artifactory.service
    sudo systemctl status artifactory.service
    echo ""
    echo "........................................"
    echo "Installation of application"
    echo "........................................"
    echo "Today's date: `date`"
    echo "........................................"
    echo ""




    • Create a new file Jenkinsfile and copy the below code in yellow color. 



    pipeline {
        agent {
          node {
            label "master"
          } 
        }

        parameters {
            string(name: 'AppName', defaultValue: 'Enter App Name', description: 'Name of application', )
            choice(choices: ['master', 'dev', 'qa', 'prod'], description: 'Select lifecycle to Deploy', name: 'Branch')
            choice(choices: ['t2.micro', 't2.small', 't2.medium'], description: 'Select Instance Size', name: 'InstanceSize')
            booleanParam(name: 'autoApprove', defaultValue: false, description: 'Automatically run apply after generating plan?')
        }


         environment {
            AWS_ACCESS_KEY_ID     = credentials('AWS_ACCESS_KEY_ID')
            AWS_SECRET_ACCESS_KEY = credentials('AWS_SECRET_ACCESS_KEY')
            TF_VAR_instance_type = "${params.InstanceSize}"
            TF_VAR_environment = "${params.Branch}"
            TF_VAR_application = "${params.AppName}"
        }
    // 

        stages {
          stage('checkout') {
            steps {
                echo "Pulling changes from the branch ${params.Branch}"
                git credentialsId: 'paste-credentialsId-here', url: 'paste-url-here' , branch: "${params.Branch}"
            }
          }

            stage('terraform plan') {
                steps {
                    sh "pwd ; terraform init -input=true"
                    sh "terraform plan -input=true -out tfplan"
                    sh 'terraform show -no-color tfplan > tfplan.txt'
    }
                }
            
            stage('terraform apply approval') {
               when {
                   not {
                       equals expected: true, actual: params.autoApprove
                   }
               }

               steps {
                   script {
                        def plan = readFile 'tfplan.txt'
                        input message: "Do you want to apply the plan?",
                        parameters: [text(name: 'Plan', description: 'Please review the plan', defaultValue: plan)]
                   }
               }
           }

            stage('terraform apply') {
                steps {
                    sh "terraform apply -input=true tfplan"
                }
            }
            
            stage('terraform destroy approval') {
                steps {
                    input 'Run terraform destroy?'
                }
            }
            stage('terraform destroy') {
                steps {
                    sh 'terraform destroy -force'
                }
            }
        }

      }

    • Commit and push code changes to Repo with the following:
      • In Vscode, navigate to Source Code Icon on the right tabs on the side
      • Enter commit message
      • Click the + icon to stage changes 

      • Push changes by clicking on the ðŸ”„0 ⬇️ 1 ⬆️ as shown below

    Run Pipeline Job

    • Go to terraform-pipeline on Jenkins and run build 
    Note: The pipeline job will fail the first time to capture the parameters in Jenkinsfile

    • The next time you run a build you should see as shown below





    • Enter Artifactory in the AppName field
    • Select a Branch/Lifecycle to deploy server
    • Choose t2.small or t2.medium for Artifactory server.
    • Go to Console Output to track progress
    Note: You can abort the destroy step and rerun the step by installing Blue Ocean Plugin on Jenkins to delete the resources created.