calebpokuackom-syself-devops

Syself // Technical Assessment for Kubernetes DevOps Internship

Helm Chart to deploy a sample backend

I created a Helm Chart to deploy an example application to a Kubernetes cluster. In this deployment, I utilized:

• Deployment: Manages replicas of the application
• Service: Defines how to access the pods
• Ingress: Exposes HTTP traffic to external users
• Secrets: Stores sensitive information needed for the application to run
• HPA: Automatically scales the number of pods in the Deployment based on CPU utilization to ensure optimal resource utilization and performance

For database, taking that the application is a stateless application, considering that;

1. I did not provide PersistentVolume and PersistentVolumeClaims for persistent storage
2. I used Deployment instead of StatefulSets.

I would recommend the use of a Serverless Database

Reasons

1. Serverless databases excel in handling stateless workloads.
2. A serverless database can automatically adjust resources in cases of load fluctuations.
3. You only pay for the resources consumed, which is/can be beneficial for initial development and testing.

Drawbacks

1. For high-performance workloads, a managed or self-managed database might be more suitable.

Production-grade Kubernetes environment

Overview

This architecture outlines a self-managed Kubernetes environment based on Ubuntu 24.04 and Kubernetes v1.30.3. It covers both the control plane and worker nodes, emphasizing high availability, scalability, and security.

Infrastructure Layer

• Virtual Machines (VMs): The underlying hardware. The VMs will host both control plane components and worker nodes.
• Private Network: Interconnecting the VMs. This will be isolated from the public internet to enhance security.
• Storage:
  • Permanent Storage: A highly-available shared block storage will be used for persistent data volumes.
  • Ephemeral Storage: VMs will have local SSD storage for container images and temporary data.
• Networking: Illustrating the overlay network for container communication.

Control Plane

The control plane is responsible for managing the cluster. It consists of etcd, API Server, Controller Manager, Scheduler, and other components deployed across multiple VMs for high availability.

• Virtual Machines: Two control plane VMs will be deployed for redundancy.
• Operating System: Ubuntu 24.04 will be installed on all control plane VMs.
• Kubernetes Components:
  • etcd: A strongly consistent, distributed key-value store will be deployed across all control plane VMs to persist the cluster's state.
  • API Server: The central point of control for the cluster, handling requests from users and clients.
  • Controller Manager: Implements core control loops like replica set, service, endpoint controller.
  • Scheduler: Decides which node to place new pods on.
  • Kubelet: Runs on each node, communicating with the control plane and managing containers.
  • Kube-proxy: Network proxy running on each node, implementing service rules.

Worker Nodes

The worker nodes provide a running environment for client applications.

• Virtual Machines: Multiple worker nodes will be deployed based on workload requirements.
• Operating System: Ubuntu 24.04 will be installed on all worker nodes.
• Container Runtime: Docker will be used as the container runtime.
• Kubelet and Kube-proxy: These components will be installed on each worker node.
• Node Local Storage: Each worker node will have local SSD storage for container images and pods.

Storage

• Persistent Volume (PV): Abstract representation of a piece of storage in the cluster.
• Persistent Volume Claim (PVC): Request for storage by a pod.
• Storage Classes: Defines how storage is created and provisioned.

Networking

• Service: Abstract way to expose a set of pods.
• Ingress: Load balancing and exposure of HTTP/HTTPS traffic.

Cluster Configuration

• Configuration Management: Ansible will be used to automate the deployment and configuration of the cluster.
• Cluster Configuration: Kubernetes configuration files (e.g., kubeconfig) will be managed securely.

Security

• Network Security: Firewalls, network segmentation, and intrusion detection systems will be implemented.
• Pod Security: Network policies, role-based access control (RBAC), and image scanning will be used.
• Secret Management: Kubernetes secrets will be used to store sensitive information.
• Encryption: Data encryption at rest and in transit will be considered.

High Availability and Disaster Recovery

• Control Plane High Availability: Two control plane instances will be deployed across different failure domains.
• Worker Node Redundancy: Multiple worker nodes will be deployed to handle failures.
• Backup and Restore: Regular backups of etcd and persistent data will be implemented.
• Disaster Recovery Plan: A comprehensive disaster recovery plan will be developed.

Monitoring and Logging

• Monitoring: Tools like Prometheus and Grafana will be used to monitor cluster health and performance.
• Logging: A centralized logging solution like Dynatrace will be implemented to scrape logs from the hosts and the pods.

Cost Optimization:

Resource utilization and cost management strategies will be implemented.

Continuous Integration and Continuous Deployment (CI/CD)

Integration of CI/CD pipelines for application deployment. GitHub Actions will be utilized to automate the test and build of the application. ArgoCD will be used to automate the delivery and deployment to the Kubernetes cluster.