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Setup

Installation Pre-reads

1. Choose the Cloud

Choose your cloud and follow the instructions to set up a Kubernetes cluster before moving on to the deployment.

On AWS

2. Deployment

3. Destroy the Cluster

Finally, clean up the cluster setup if you wish, using the following command. This will delete the entire cluster and other cloud resources that were provisioned for the DIGIT setup.

cd DIGIT-DevOps/infra-as-code/terraform/my-digit-eks
terraformdestroy​

Conclusion

We have successfully created infra on cloud, and deployed DIGIT in the cluster.

On AWS

Pre-read:

Prerequisites

  7. ​

    1. You will get a Secret Access Key and Access Key ID. Save them.

    2. Open the terminal and run the following command. You have already installed the AWS CLI, and you have the credentials saved. (Provide the credentials. You can leave the region and output format blank).

    The above will create the following file in your machine as /Users/.aws/credentials.

Before we provision cloud resources, we must understand what resources need to be provisioned by Terraform to deploy DIGIT.

The following picture shows the key components (EKS, Worker Nodes, Postgress DB, EBS Volumes, Load Balancer).

EKS Architecture for DIGIT Setup

Considering the above deployment architecture, the following is the resource graph we will provision using Terraform in a standard way so that every time and for every env, it will have the same infra.

  • EKS control plane (Kubernetes master)

  • Work node group (VMs with the estimated number of vCPUs, memory)

  • EBS volumes (Persistent volumes)

  • RDS (PostGres)

  • VPCs (Private network)

  • Users to access, deploy, and read-only

Understand the resource graph in Terraform script:

  • Here, we have already written the Terraform script that provisions the production-grade DIGIT infra and can be customised with the specified configuration.

Example:

  • VPC Resources:

    • VPC

    • Subnets

    • Internet Gateway

    • Route Table

  • EKS Cluster Resources:

    • IAM Role to allow EKS service to manage other AWS services.

    • EC2 Security Group to allow networking traffic with the EKS cluster.

    • EKS Cluster.

  • EKS Worker Nodes Resources:

    • IAM role allowing Kubernetes actions to access other AWS services.

    • EC2 Security Group to allow networking traffic.

    • Data source to fetch the latest EKS worker AMI.

    • AutoScaling Launch Configuration to configure worker instances.

    • AutoScaling Group to launch worker instances.

  • Database

    • Configuration in this directory creates a set of RDS resources, including DB instance, DB subnet group, and DB parameter group.

  • Storage Module

    • Configuration in this directory creates EBS volume and attaches it together.

    ​

  • The following main.tf with create s3 bucket to store all the state of the execution to keep track.

    iFix-DevOps/Infra-as-code/terraform/sample-aws/remote-state

    main.tf.​

provider "aws" {
  region = "ap-south-1"
}

#This is a bucket name that you can name as you wish
resource "aws_s3_bucket" "terraform_state" {
  bucket = "try-workshop-yourname" 

  versioning {
    enabled = true
  }

  lifecycle {
    prevent_destroy = true
  }
}

#This is a bucket name that you can name as you wish
resource "aws_dynamodb_table" "terraform_state_lock" {
  name           = "try-workshop-yourname"
  read_capacity  = 1
  write_capacity = 1
  hash_key       = "LockID"

  attribute {
    name = "LockID"
    type = "S"
  }
}

  1. The following main.tf contains the detailed resource definitions that need to be provisioned.

    Dir: iFix-DevOps/Infra-as-code/terraform/sample-aws

    main.tf

# master configs, terraform state helps to maintain the flow of the execution
terraform {
  backend "s3" {
    bucket = "try-workshop-yourname"
    key = "terraform"
    region = "ap-south-1"
  }
}

# Network Module
module "network" {
  source             = "../modules/kubernetes/aws/network"
  vpc_cidr_block     = "${var.vpc_cidr_block}"
  cluster_name       = "${var.cluster_name}"
  availability_zones = "${var.network_availability_zones}"
}

# PostGres DB
module "db" {
  source                        = "../modules/db/aws"
  subnet_ids                    = "${module.network.private_subnets}"
  vpc_security_group_ids        = ["${module.network.rds_db_sg_id}"]
  availability_zone             = "${element(var.availability_zones, 0)}"
  instance_class                = "db.t3.medium"
  engine_version                = "11.5"
  storage_type                  = "gp2"
  storage_gb                    = "100"
  backup_retention_days         = "7"
  administrator_login           = "egovdev"
  administrator_login_password  = "${var.db_password}"
  db_name                       = "${var.cluster_name}-db"
  environment                   = "${var.cluster_name}"
}

# **********  Uses with various access like Admin, Dev, Deploy
module "iam_user_deployer" {
  source  = "terraform-aws-modules/iam/aws//modules/iam-user"

  name          = "${var.cluster_name}-kube-deployer"
  force_destroy = true  
  create_iam_user_login_profile = false
  create_iam_access_key         = true

  # User "egovterraform" has uploaded his public key here - https://keybase.io/egovterraform/pgp_keys.asc
  pgp_key = "${var.iam_keybase_user}"
}

module "iam_user_admin" {
  source  = "terraform-aws-modules/iam/aws//modules/iam-user"

  name          = "${var.cluster_name}-kube-admin"
  force_destroy = true  
  create_iam_user_login_profile = false
  create_iam_access_key         = true

  # User "egovterraform" has uploaded his public key here - https://keybase.io/egovterraform/pgp_keys.asc
  pgp_key = "${var.iam_keybase_user}"
}

module "iam_user_user" {
  source  = "terraform-aws-modules/iam/aws//modules/iam-user"

  name          = "${var.cluster_name}-kube-user"
  force_destroy = true  
  create_iam_user_login_profile = false
  create_iam_access_key         = true

  # User "test" has uploaded his public key here - https://keybase.io/test/pgp_keys.asc
  pgp_key = "${var.iam_keybase_user}"
}



# ********** EKS Cluster (Control Plane) **********
data "aws_eks_cluster" "cluster" {
  name = "${module.eks.cluster_id}"
}

data "aws_eks_cluster_auth" "cluster" {
  name = "${module.eks.cluster_id}"
}
provider "kubernetes" {
  host                   = "${data.aws_eks_cluster.cluster.endpoint}"
  cluster_ca_certificate = "${base64decode(data.aws_eks_cluster.cluster.certificate_authority.0.data)}"
  token                  = "${data.aws_eks_cluster_auth.cluster.token}"
  load_config_file       = false
  version                = "~> 1.11"
}

module "eks" {
  source          = "terraform-aws-modules/eks/aws"
  cluster_name    = "${var.cluster_name}"
  cluster_version = "${var.kubernetes_version}"
  subnets         = "${concat(module.network.private_subnets, module.network.public_subnets)}"

  tags = "${
    map(
      "kubernetes.io/cluster/${var.cluster_name}", "owned",
      "KubernetesCluster", "${var.cluster_name}"
    )
  }"

  vpc_id = "${module.network.vpc_id}"

  # ********** Worker Nodes
  worker_groups_launch_template = [
    {
      name                    = "spot"
      subnets                 = "${concat(slice(module.network.private_subnets, 0, length(var.availability_zones)), slice(module.network.public_subnets, 0, length(var.availability_zones)))}"
      override_instance_types = "${var.override_instance_types}"
      asg_max_size            = 4
      asg_desired_capacity    = 4
      kubelet_extra_args      = "--node-labels=node.kubernetes.io/lifecycle=spot"
      additional_security_group_ids = ["${module.network.worker_nodes_sg_id}"]
      spot_allocation_strategy= "capacity-optimized"
      spot_instance_pools     = null
    },
  ]

  map_users    = [
    {
      userarn  = "${module.iam_user_deployer.this_iam_user_arn}"
      username = "${module.iam_user_deployer.this_iam_user_name}"
      groups   = ["system:masters"]
    },
    {
      userarn  = "${module.iam_user_admin.this_iam_user_arn}"
      username = "${module.iam_user_admin.this_iam_user_name}"
      groups   = ["global-readonly", "digit-user"]
    },
    {
      userarn  = "${module.iam_user_user.this_iam_user_arn}"
      username = "${module.iam_user_user.this_iam_user_name}"
      groups   = ["global-readonly"]
    },    
  ]
}

# ********** EBS Volumes for the statefulsets (PVCs)
module "es-master" {

  source = "../modules/storage/aws"
  storage_count = 3
  environment = "${var.cluster_name}"
  disk_prefix = "es-master"
  availability_zones = "${var.availability_zones}"
  storage_sku = "gp2"
  disk_size_gb = "2"

}
module "es-data-v1" {

  source = "../modules/storage/aws"
  storage_count = 3
  environment = "${var.cluster_name}"
  disk_prefix = "es-data-v1"
  availability_zones = "${var.availability_zones}"
  storage_sku = "gp2"
  disk_size_gb = "25"

}

module "zookeeper" {

  source = "../modules/storage/aws"
  storage_count = 3
  environment = "${var.cluster_name}"
  disk_prefix = "zookeeper"
  availability_zones = "${var.availability_zones}"
  storage_sku = "gp2"
  disk_size_gb = "2"

}

module "kafka" {

  source = "../modules/storage/aws"
  storage_count = 3
  environment = "${var.cluster_name}"
  disk_prefix = "kafka"
  availability_zones = "${var.availability_zones}"
  storage_sku = "gp2"
  disk_size_gb = "50"

}

Custom variables/configurations:

You can define your configurations in variables.tf and provide the env-specific cloud requirements so that using the same Terraform template, you can customise the configurations.

├── iFix-dev
│   ├── main.tf 
│   ├── outputs.tf
│   ├── providers.tf
│   ├── remote-state
│   │   └── main.tf
│   └── variables.tf

Following are the values you need to mention in the following files. The blank ones will be prompted for inputs during execution.

​variables.tf ​

## Add Cluster Name
variable "cluster_name" {
  default = "<Desired Cluster name>"  #eg: my-digit-eks
}

## Add vpc_cidr_block
variable "vpc_cidr_block" {
  default = "CIDR" 
}

# If you want prod grade N/W, you can define HA, DRS with multi zone
variable "network_availability_zones" {  
  default = ["ap-south-1b", "ap-south-1a"]
}

# Which zone, it matters
variable "availability_zones" {
  default = ["ap-south-1b"]
}

variable "kubernetes_version" {
  default = "1.18"
}

# instance type for your worker nodes like r5a.large is 8 vCPU and 16GB RAM
variable "instance_type" {
  default = "r5a.large"
}

# spot instance configuration
variable "override_instance_types" {
  default = ["r5a.large", "r5ad.large", "r5d.large", "t3a.xlarge"] 
}

# number of machines as per estimate
variable "number_of_worker_nodes" {
  default = "3"
}

##Add ssh key in case you want to ssh to nodes
variable "ssh_key_name" {
  default = "ssh key name"
}

# terraform users ssh public key, you need to one for you, refer below to create yours
variable "iam_keybase_user" {
  default = "keybase:egovterraform"
}

# will be prompted to provide during the execution
variable "db_password" {}

​

Important: Create your keybase key before you run the terraform

  • Use this URL https://keybase.io/ to create your PGP key to create both public and private keys in your machine. Upload the public key into the keybase account that you have created, give it a name, and ensure that you mention that in your Terraform. This allows you to encrypt sensitive information.

    • Example: User keybase user in eGov case is "egovterraform" that needs to be created and the public key needs to be uploaded here: https://keybase.io/egovterraform/pgp_keys.asc​

    • You can use this portal to decrypt your secret key. To decrypt a PGP message, upload the PGP message, PGP private key, and passphrase.

Run Terraform

Now that we know what the Terraform script does, the resources graph that it provisions, and what custom values should be given to your env, let us begin to run the Terraform scripts to provision infra required for deploying DIGIT on AWS.

  1. First CD into the following directory, run the following command 1-by-1, and watch the output closely.

cd DIGIT-DevOps/infra-as-code/terraform/sample-aws/remote-state
terraform init
terraform plan
terraform apply


cd DIGIT-DevOps/infra-as-code/terraform/sample-aws
terraform init
terraform plan
terraform apply

Upon successful execution, the following resources get created, which can be verified by the command "terraform output".

  • s3 bucket: to store terraform state.

  • Network: VPC, security groups.

  • IAM users auth: using keybase to create admin, deployer, the user. Use this URL https://keybase.io/ to create your own PGP key to create both public and private keys in your machine. Upload the public key into the keybase account that you have just created, give it a name, and mention that in your terraform. This allows you to encrypt sensitive information.

    • Example: User keybase user in eGov case is "egovterraform" that needs to be created, and public keys need to be uploaded here: https://keybase.io/egovterraform/pgp_keys.asc​

    • You can use this portal to decrypt your secret key. To decrypt a PGP message, upload the PGP message, PGP private key, and passphrase.

  • EKS cluster: with master(s) & worker node(s).

  • Storage(s): for es-master, es-data-v1, es-master-infra, es-data-infra-v1, zookeeper, kafka, kafka-infra.

  • Use this link to get the kubeconfig from EKS in order to get the kubeconfig file and connect to the cluster from your local machine. This enables you deploy DIGIT services to the cluster.

aws sts get-caller-identity

# Run the below command and give the respective region-code and the cluster name
aws eks --region <region-code> update-kubeconfig --name <cluster_name>

  1. Finally, verify that you can connect to the cluster by running the following command.

kubectl config use-context <your cluster name>

kubectl get nodes

NAME                                             STATUS AGE   VERSION               OS-Image           
ip-192-168-xx-1.ap-south-1.compute.internal   Ready  45d   v1.15.10-eks-bac369   Amazon Linux 2   
ip-192-168-xx-2.ap-south-1.compute.internal   Ready  45d   v1.15.10-eks-bac369   Amazon Linux 2   
ip-192-168-xx-3.ap-south-1.compute.internal   Ready  45d   v1.15.10-eks-bac369   Amazon Linux 2   
ip-192-168-xx-4.ap-south-1.compute.internal   Ready  45d   v1.15.10-eks-bac369   Amazon Linux 2

You are all set to deploy the product.