Microservices Deployment on EKS

Step-00: What are Microservices?

Understand what are microservices on a very high level

Step-01: What are we going to learn in this section?

We are going to deploy two microservices.
- User Management Service
- Notification Service

Usecase Description

User Management Create User API will call Notification service Send Notification API to send an email to user when we create a user.

List of Docker Images used in this section

Application Name	Docker Image Name
User Management Microservice	stacksimplify/kube-usermanagement-microservice:1.0.0
Notifications Microservice V1	stacksimplify/kube-notifications-microservice:1.0.0
Notifications Microservice V2	stacksimplify/kube-notifications-microservice:2.0.0

Step-02: Pre-requisite -1: AWS RDS Database, ALB Ingress Controller & External DNS

AWS RDS Database

We have created AWS RDS Database as part of section 06-EKS-Storage-with-RDS-Database
We even created a externalName service: 01-MySQL-externalName-Service.yml in our Kubernetes manifests to point to that RDS Database.

ALB Ingress Controller & External DNS

We are going to deploy a application which will also have a ALB Ingress Service and also will register its DNS name in Route53 using External DNS
Which means we should have both related pods running in our EKS cluster.
We have installed ALB Ingress Controller as part of section 08-01-ALB-Ingress-Install
We have installed External DNS as part of section 08-06-01-Deploy-ExternalDNS-on-EKS

# Verify alb-ingress-controller pod running in namespace kube-system
kubectl get pods -n kube-system

# Verify external-dns pod running in default namespace
kubectl get pods

Step-03: Pre-requisite-2: Create Simple Email Service - SES SMTP Credentials

SMTP Credentials

Go to Services -> Simple Email Service
SMTP Settings --> Create My SMTP Credentials
IAM User Name: append the default generated name with microservice or something so we have a reference of this IAM user created for our ECS Microservice deployment
Download the credentials and update the same for below environment variables which you are going to provide in kubernetes manifest 04-NotificationMicroservice-Deployment.yml

AWS_MAIL_SERVER_HOST=email-smtp.us-east-1.amazonaws.com
AWS_MAIL_SERVER_USERNAME=****
AWS_MAIL_SERVER_PASSWORD=***
AWS_MAIL_SERVER_FROM_ADDRESS= use-a-valid-email@gmail.com

Important Note: Environment variable AWS_MAIL_SERVER_FROM_ADDRESS value should be a valid email address and also verified in SES.

Verfiy Email Addresses to which notifications we need to send.

We need two email addresses for testing Notification Service.
Email Addresses
- Verify a New Email Address
- Email Address Verification Request will be sent to that address, click on link to verify your email.
- From Address: stacksimplify@gmail.com (replace with your ids during verification)
- To Address: dkalyanreddy@gmail.com (replace with your ids during verification)
Important Note: We need to ensure all the emails (FromAddress email) and (ToAddress emails) to be verified here.
- Reference Link: https://docs.aws.amazon.com/ses/latest/DeveloperGuide/verify-email-addresses.html
Environment Variables
- AWS_MAIL_SERVER_HOST=email-smtp.us-east-1.amazonaws.com
- AWS_MAIL_SERVER_USERNAME=*****
- AWS_MAIL_SERVER_PASSWORD=*****
- AWS_MAIL_SERVER_FROM_ADDRESS=stacksimplify@gmail.com

Step-04: Create Notification Microservice Deployment Manifest

Update environment Variables for Notification Microservice
Notification Microservice Deployment

          - name: AWS_MAIL_SERVER_HOST
            value: "smtp-service"
          - name: AWS_MAIL_SERVER_USERNAME
            value: "AKIABCDEDFASUBKLDOAX"
          - name: AWS_MAIL_SERVER_PASSWORD
            value: "Bdsdsadsd32qcsads65B4oLo7kMgmKZqhJtEipuE5unLx"
          - name: AWS_MAIL_SERVER_FROM_ADDRESS
            value: "stacksimplify@gmail.com"

Step-05: Create Notification Microservice SMTP ExternalName Service

apiVersion: v1
kind: Service
metadata:
  name: smtp-service
spec:
  type: ExternalName
  externalName: email-smtp.us-east-1.amazonaws.com

Step-06: Create Notification Microservice NodePort Service

apiVersion: v1
kind: Service
metadata:
  name: notification-clusterip-service
  labels:
    app: notification-restapp
spec:
  type: ClusterIP
  selector:
    app: notification-restapp
  ports:
  - port: 8096
    targetPort: 8096

Step-07: Update User Management Microservice Deployment Manifest with Notification Service Environment Variables.

User Management Service new environment varibales related to Notification Microservice in addition to already which were configured related to MySQL
Update in 02-UserManagementMicroservice-Deployment.yml

          - name: NOTIFICATION_SERVICE_HOST
            value: "notification-clusterip-service"
          - name: NOTIFICATION_SERVICE_PORT
            value: "8096"

Step-08: Update ALB Ingress Service Kubernetes Manifest

Update Ingress Service to ensure only target it is going to have is User Management Service
Remove /app1, /app2 contexts

    # External DNS - For creating a Record Set in Route53
    external-dns.alpha.kubernetes.io/hostname: services.kubeoncloud.com, ums.kubeoncloud.com
spec:
  rules:
    - http:
        paths:
          - path: /* # SSL Redirect Setting
            backend:
              serviceName: ssl-redirect
              servicePort: use-annotation                   
          - path: /*
            backend:
              serviceName: usermgmt-restapp-nodeport-service
              servicePort: 8095

Step-09: Deploy Microservices manifests

# Deploy Microservices manifests
kubectl apply -f V1-Microservices/

Step-10: Verify the Deployment using kubectl

# List Pods
kubectl get pods

# User Management Microservice Logs
kubectl logs -f $(kubectl get po | egrep -o 'usermgmt-microservice-[A-Za-z0-9-]+')

# Notification Microservice Logs
kubectl logs -f $(kubectl get po | egrep -o 'notification-microservice-[A-Za-z0-9-]+')

# External DNS Logs
kubectl logs -f $(kubectl get po | egrep -o 'external-dns-[A-Za-z0-9-]+')

# List Ingress
kubectl get ingress

Step-11: Verify Microservices health-status via browser

# User Management Service Health-Status
https://services.kubeoncloud.com/usermgmt/health-status

# Notification Microservice Health-Status via User Management
https://services.kubeoncloud.com/usermgmt/notification-health-status
https://services.kubeoncloud.com/usermgmt/notification-service-info

Step-12: Import postman project to Postman client on our desktop.

Import postman project
Add environment url
- https://services.kubeoncloud.com (Replace with your ALB DNS registered url on your environment)

Step-13: Test both Microservices using Postman

User Management Service

Create User
- Verify the email id to confirm account creation email received.
List User
- Verify if newly created user got listed.

Step-14: Rollout New Deployment - Set Image Option

# Rollout New Deployment using Set Image
kubectl set image deployment/notification-microservice notification-service=stacksimplify/kube-notifications-microservice:2.0.0 --record=true

# Verify Rollout Status
kubectl rollout status deployment/notification-microservice

# Verify ReplicaSets
kubectl get rs

# Verify Rollout History
kubectl rollout history deployment/notification-microservice

# Access Application (Should see V2)
https://services.kubeoncloud.com/usermgmt/notification-health-status

# Roll back to Previous Version
kubectl rollout undo deployment/notification-microservice

# Access Application (Should see V1)
https://services.kubeoncloud.com/usermgmt/notification-health-status

Step-15: Rollout New Deployment - kubectl Edit

# Rollout New Deployment using kubectl edit, change image version to 2.0.0
kubectl edit deployment/notification-microservice

# Verify Rollout Status
kubectl rollout status deployment/notification-microservice

# Verify ReplicaSets
kubectl get rs

# Verify Rollout History
kubectl rollout history deployment/notification-microservice

# Access Application (Should see V2)
https://services.kubeoncloud.com/usermgmt/notification-health-status

# Roll back to Previous Version
kubectl rollout undo deployment/notification-microservice

# Access Application (Should see V1)
https://services.kubeoncloud.com/usermgmt/notification-health-status

Step-16: Rollout New Deployment - Update manifest & kubectl apply

# Rollout New Deployment by updating yaml manifest 2.0.0
kubectl apply -f kube-manifests/

# Verify Rollout Status
kubectl rollout status deployment/notification-microservice

# Verify ReplicaSets
kubectl get rs

# Verify Rollout History
kubectl rollout history deployment/notification-microservice

# Access Application (Should see V2)
https://services.kubeoncloud.com/usermgmt/notification-health-status

# Roll back to Previous Version
kubectl rollout undo deployment/notification-microservice

# Access Application (Should see V1)
https://services.kubeoncloud.com/usermgmt/notification-health-status

Step-17: Clean-up

kubectl delete -f kube-manifests/