Counter Online

Counter Online is just my learning project to experiment some technologies. Here you will find:

• Backend app written in Go language (using GO kit)
• Terraform to deploy infrastructure components on AWS
• Kubernetes to manage app containers
• GitHub Actions to CI/CD
• AWS as a cloud provider

Introduction

Imagine following scenario: sellers wants to keep their product authenticity and users want to check it to get quality goods. You can provide together their product a unique identifier to be validated online. When user validate it for the first time, the counter is one. This means that no one else validated the code before and it can be considered authentic. If another manufacturer makes a copy and sell it as original, they need to give the validation code to customers. If customers tries to validate, the code can be already used or invalid.

Development state

Feature	Description	State	Comment
Documentation	Document the process and architecture	In progress	-
Counter App Service	The counter application	Ready	-
Counter App Service	Use GO kit to create services	Ready	-
Counter App Service Build	The counter continuous integration (CI)	Ready	-
Counter App Service Deployment	The counter application deployment (CD)	Ready	-
AWS Infrastructure (Terraform)	Terraform files to create infrastructure	Ready	-
AWS Infrastructure (Terraform) Deployment	Terraform infrastructure pipeline (CD)	Ready	-
AWS Password Manager CSI Driver	CSI driver deployment	Ready	-
AWS Password Manager CSI Provider	CSI provider deployment	Ready	-
AWS Kubernetes Cluster Autoscaler	Automatically adjusts the number of nodes when needed	Ready	-
AWS Kubernetes Cluster Autoscaler Deployment	AWS Kubernetes Cluster Autoscaler pipeline	Ready	-
Ingress Nginx	Kubernetes ingress deployment	Ready	-
DNS Management	Implement DNS Management	Not started	-
CertManager	Implement Cert Manager	Not started	-

Folders

This project is organized as follows:

Folder	Description
.github/workflows	GitHub action workflow pipelines
app	App source code in GO Language
terraform	Terraform HCL files to deploy infrastructure
deployments	Kubernetes Deployment folders to create basic infrastructure software elements like ingress
scripts	Scripts used help to prepare terraform infrastructure, creating aws user, policies, s3, etc

IMPORTANT: In a production environment, you must use different repositories to each component (application, kubernetes deployments, terraform...)

Architecture

Workflow

This is the use case for this project. Here we have the seller creating UUID v5 codes to be validated by the customer (maybe using qr code), as you saw in the beginning of this document.

Infrastructure Architecture

Above you will find the application architecture. I used AWS provider and terraform to deploy infrastructure components.

How to use this repository

I recommend you fork this repository and change it to use your own parameters. The next two sections, I'll show you what you gonna need to do.

GitHub Actions secret variables

These are GitHub Action variables needed by automation. Please, create these key-values inside your github repository:

Variable Name	Description
AWS_SECRET_ACCESS_KEY	Store your AWS provider access key
AWS_ACCESS_KEY_ID	Store your AWS provider secret key
AWS_DEFAULT_REGION	Your AWS provider Region
TERRAFORM_GITHUB_TOKEN	Create a GitHub PAT (default token doesn't work]

AWS Credenciais and Terraform resources

This project is using Terraform to maintain the infrastructure. You need to configure credentials, permissions and storage to maintain state. You can use the scripts/startup-terraform-backend-state.sh script to help you.

Account configuration

Some files have AWS account ID hardcoded. You can replace these values with your AWS account id using find ./ -type f -exec sed -i 's/043934856969/100000000001/g' {} \; where 100000000001 is your aws acccount id.

If you want to change every file manually or check each configuration, here is the list

Open file go-counter-online/deployments/kustomize/common/base/service-account.yaml and change:

eks.amazonaws.com/role-arn: arn:aws:iam::043934856969:role/AmazonSCPRole

to

eks.amazonaws.com/role-arn: arn:aws:iam::<your aws account id>:role/AmazonSCPRole

Open file go-counter-online/deployments/specs/aws-cluster-autoscaler-service/cluster-autoscaler-autodiscover.yaml and change:

eks.amazonaws.com/role-arn": "arn:aws:iam::043934856969:role/AmazonEKSClusterAutoscalerRole

to

eks.amazonaws.com/role-arn": "arn:aws:iam::<your aws account id>:role/AmazonEKSClusterAutoscalerRole

Open file go-counter-online/deployments/specs/aws-load-balancer-controler-service/aws-load-balancer-controller-service-account.yaml and change:

eks.amazonaws.com/role-arn: arn:aws:iam::043934856969:role/AmazonEKSLoadBalancerControllerRole

to

eks.amazonaws.com/role-arn: arn:aws:iam::<your aws account id>:role/AmazonEKSLoadBalancerControllerRole

Open file go-counter-online/deployments/specs/aws-load-balancer-controler-service/aws-load-balancer-controller-service-account.yaml and change:

eks.amazonaws.com/role-arn: arn:aws:iam::043934856969:role/AmazonEKSLoadBalancerControllerRole

to

eks.amazonaws.com/role-arn: arn:aws:iam::<your aws account id>:role/AmazonEKSLoadBalancerControllerRole

Open file go-counter-online/terraform/iam.tf and change:

"Resource": ["arn:aws:secretsmanager:us-east-2:043934856969:secret:*"]

to

"Resource": ["arn:aws:secretsmanager:us-east-2:<your aws account id>:secret:*"]

Miscellaneous

Useful commands

Update kubeconfig to access EKS Cluster:

aws eks update-kubeconfig --name prd-go-counter-online-eks

Docker build to test local:

docker build -t go-counter-online -f app/Dockerfile app

Add users and roles to access the cluster:

kubectl -n kube-system edit configmap aws-auth

# Add user test like this:
# 043934856969 is your account code
data:
  (... other stuffs)
  mapUsers: |
    - userarn: arn:aws:iam::043934856969:user/test
      username: test
      groups:
      - system:masters

Command line to run Counter Online local

# memory database
go run . -port=8080 -datastore=memory

# or postgresql database
go run . -port=8080 -datastore=postgresql -extra-params='host=localhost dbname=go_counter_online user=go_counter_online password=go_counter_online_password sslmode=disable' -hide-extra-params=true

Curl commands to test Counter Online API services

# Create counter with UUID v5 AAAAAAAA-AAAA-5AAA-AAAA-AAAAAAAAAAAA using name test:
curl -v -XPOST localhost:8080/count/AAAAAAAA-AAAA-5AAA-AAAA-AAAAAAAAAAAA/test

# Consume counter with UUID v5 AAAAAAAA-AAAA-5AAA-AAAA-AAAAAAAAAAAA:
curl -v -XGET localhost:8080/count/AAAAAAAA-AAAA-5AAA-AAAA-AAAAAAAAAAAA

Deploy PSQL to test database

Use psql utility to connect to Postgres database:

#docker
docker run -it --rm postgres psql -h <dbhost> -U go_counter_online -d go_counter_online

#kubernetes
kubectl run psql --rm -it --image=postgres -- psql -h <dbhost> -U go_counter_online -d go_counter_online

Links

Configure AWS EKS Kubernetes Cluster Autoscaler

Autoscaling is a function that automatically scales your resources up or down to meet changing demands. This is a major Kubernetes function that would otherwise require extensive human resources to perform manually.

More info: https://docs.aws.amazon.com/eks/latest/userguide/autoscaling.html

Kubernetes Ingress Nginx

Ingress exposes HTTP and HTTPS routes from outside the cluster to services within the cluster. Traffic routing is controlled by rules defined on the Ingress resource.

More info: https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.1.0/deploy/static/provider/aws/deploy.yaml