Kubernetes Clusters | Upstream Vs Downstream.

 

The terms "upstream" and "downstream" in the context of Kubernetes clusters often refer to the direction of code flow, contributions, and customization of the cluster.

Here's twtech clear breakdown:

 Kubernetes Clusters – Upstream vs Downstream

 Upstream Kubernetes

 What It Means:

·        The official Kubernetes project maintained by the Cloud Native Computing Foundation (CNCF).

·        Source of truth: https://github.com/kubernetes/kubernetes

·        It’s the pure, open-source version without vendor modifications.

Characteristics:

·        Community-developed and maintained.

·        Vendor-neutral, portable across environments.

·        Releases, features, and bug fixes originate here.

 Example Use:

·        Building a custom Kubernetes distribution.

·        Running a lab or sandbox cluster using tools like kubeadm, kind, or minikube.

 Downstream Kubernetes

What It Means:

·        A modified or curated version of upstream Kubernetes provided by vendors.

·        Adds features, integrations, or enterprise support.

 Characteristics:

·        May include:

o   Custom dashboards

o   Security patches

o   Better cloud integrations

o   Proprietary extensions or operators

·        Follows upstream releases but may lag behind slightly.

·        May remove or restrict certain upstream features for stability or policy.

 Examples:

·        Amazon EKS (AWS's downstream distro of Kubernetes)

·        Google Kubernetes Engine (GKE)

·        Red Hat OpenShift (based on upstream, but heavily customized)

·        Rancher Kubernetes Engine (RKE)

 Comparison Table

Feature	Upstream Kubernetes	Downstream Kubernetes (Vendor)
Source.	CNCF / Community	Based on upstream
Customization.	Raw Kubernetes	Vendor-specific
Support.	Community-driven	Enterprise support available
Release Cadence.	Rapid	May lag for stability/testing
Integrations.	Manual	Built-in (IAM, networking, etc)
Ideal For.	Custom builds, research, labs	Production, enterprise, managed

When to Use Each

twtech Uses Upstream Kubernetes if: Like kubeadm

·        twtech wants full control.

·        twtech is contributing to Kubernetes.

·        twtech is building a custom Kubernetes distribution.

twtech Uses Downstream Kubernetes if:  Like EKS

·        twtech wants a ready-to-use, production-ready, or managed solution.

·        twtech needs enterprise support, integrated logging, monitoring, or security.

·        twtech want to minimize operational overhead.

twteh Insights

Here are real-world examples of upstream and downstream Kubernetes clusters, to help anyone clearly understand the distinction:

 Upstream Kubernetes Clusters (Open Source / Community-Based)

These clusters run the vanilla, unmodified version of Kubernetes from the CNCF:

Example Cluster	Description
kubeadm	Tool provided by the Kubernetes project to install and bootstrap upstream clusters. Used in self-hosted or lab environments.
kind	“Kubernetes IN Docker” – used for local development/testing using upstream Kubernetes.
minikube	Local, lightweight upstream Kubernetes cluster for development or learning.
k3s (by Rancher)	Lightweight upstream-compatible Kubernetes distro optimized for edge/IoT.
bare-metal clusters using upstream tarballs	Direct installs using official Kubernetes releases and binaries from GitHub.

 Downstream Kubernetes Clusters (Vendor-Modified / Managed)

These are vendor-distributed or managed Kubernetes clusters that are based on (but often extend) upstream Kubernetes:

Vendor Cluster	Description
Amazon EKS	AWS-managed Kubernetes with VPC, IAM, Fargate, and CloudWatch integration.
Google Kubernetes Engine (GKE).	GCP-managed Kubernetes with tight integration into Google Cloud services.
Azure Kubernetes Service (AKS).	Microsoft’s managed Kubernetes offering with Azure-native features.
Red Hat OpenShift.	Enterprise Kubernetes built on upstream but with added CI/CD, security, and operator lifecycle management.
VMware Tanzu Kubernetes Grid.	VMware’s enterprise Kubernetes distribution, tailored for vSphere and multi-cloud.
Rancher (RKE, RKE2).	Rancher-managed Kubernetes clusters that simplify and harden upstream Kubernetes.
Canonical Kubernetes (Charmed Kubernetes).	Downstream distro with additional automation and enterprise support from Canonical (Ubuntu).

 Visualization of Code Flow

# text

                 [Upstream Kubernetes Project]

                                  ↓

   ┌───────────────────────────────┐

   │              Vendors fork, extend, patch                  │

   └───────────────────────────────┘

                                   ↓

            [Downstream Kubernetes Distros]

twtech-Summary

Type	Examples	Use Case
Upstream.	kubeadm, kind, minikube, k3s.	Test, development, research
Downstream.	EKS, GKE, AKS, OpenShift, Rancher, Tanzu.	Production, enterprise, cloud

Amazon EKS | Node Types.

 

Amazon EKS supports two main node types for running your Kubernetes workloads:

 Amazon EKS Node Types

1 Managed Node Groups (EC2-based)

What it is:

·        AWS provisions and manages a group of EC2 instances on twtech behalf.

·        These are registered as worker nodes in twtech EKS cluster.

 Key Features:

·        Automatic updates (AMI patching).

·        Integrated with Auto Scaling Groups.

·        Launch templates and custom AMIs supported.

·        twtech manages the EC2 instance size, type, and capacity.

twtech Use Cases:

·        General workloads that require customization (e.g., GPU, high memory).

·        Scenarios where full control over the instance is needed.

2 Fargate (Serverless)

 What it is:

·        Serverless compute for containers.

·        twtech doesn’t provision or manage EC2 instances.

·        twtech defines Fargate profiles to run certain pods in Fargate.

 Key Features:

·        No servers to manage.

·        Per-pod billing (CPU & memory).

·        Isolation per pod using Firecracker microVMs.

·        Native IAM, logging, and VPC integration.

twtech Use Cases:

·        Lightweight, bursty, or infrequent workloads.

·        Dev/test environments.

·        twtech wants to avoid infrastructure management.

3  Self-Managed Nodes (EC2-based, legacy option)

 What it is:

·        twtech manually provision EC2 instances and join them to the EKS cluster.

 Key Features:

·        Full control of lifecycle and configuration.

·        twtech  Must handle patching, scaling, and health checks itself.

·        Requires knowledge of Kubernetes bootstrapping.

 Use Cases:

·        Legacy clusters.

·        Highly customized infrastructure needs.

·        Use with tools like Kops or custom automation.

 twtech Summary Table

Node Type	Managed by AWS	Serverless	Custom AMI Support	Auto Scaling	Best for
Managed Node Group.	✅ Yes	❌ No	✅ Yes	✅ Yes	General-purpose workloads
Fargate.	✅ Yes	✅ Yes	❌ No	✅ Yes (via profile)	Serverless, simple workloads
Self-Managed.	❌ No	❌ No	✅ Yes	⚠️ Manual	Legacy or advanced customization

Amazon EKS (Elastic Kubernetes Service).

Amazon EKS (Elastic Kubernetes Service)

The concept:  Amazon EKS

Amazon Elastic Kubernetes Service (EKS) is a managed Kubernetes service that makes it easy to deploy, manage, and scale containerized applications using Kubernetes on AWS infrastructure.

Kubernetes is cloud-agnostic... it can be used with services of Multi-Cloud providers  like,  Azure, GCP and many more.

 Key Features

Feature	Description
Fully Managed Control Plane.	AWS manages the Kubernetes control plane (API servers, etcd), including scalability and availability.
Integration with AWS Services.	Native integration with IAM, VPC, CloudWatch, ELB, EBS, and more.
Supports EC2 and Fargate.	twtech can run workloads on either Amazon EC2 or AWS Fargate (serverless).
High Availability.	Control plane is automatically deployed across multiple Availability Zones.
Security.	IAM-based authentication, Kubernetes RBAC, and support for PrivateLink and encryption.

 EKS Architecture Overview

1. Control Plane (Managed by AWS)
• Kubernetes API server
• etcd database
• Control plane logs available via CloudWatch
2. Worker Nodes (Managed by twtech)
• EC2 Instances (self-managed or managed node groups)
• Fargate (serverless pods)
3. Networking
• Integrates with Amazon VPC
• Uses Amazon VPC CNI plugin for pod networking (pods get VPC IPs)

 How twtect Uses Amazon EKS

1. Create an EKS Cluster
• Via Console, CLI, CloudFormation, or Terraform
2. Provision Worker Nodes
• EC2 (via node groups) or Fargate profiles
3. Configure kubectl
• Connect to the EKS API using kubectl and the AWS CLI
4. Deploy Applications
• Use standard Kubernetes manifests (YAML)

 Pricing

• Control Plane: ~$0.10/hour per cluster
• Compute: Based on EC2 or Fargate pricing
• Other Costs: Networking, EBS, and logging (CloudWatch)

 When to Use EKS

• twtech should already be using Kubernetes and want a managed solution.
• twtech wants tight integration with AWS services.
• twtech needs multi-AZ, scalable, secure Kubernetes clusters.
• twtech wants to avoid managing the Kubernetes control plane, so aws can do the management.

EKS cluster vs ECS cluster vs Self-Managed Kubernetes cluster:

Here's a clear comparison of Amazon EKS, Amazon ECS, and Self-Managed Kubernetes across key dimensions:

 EKS vs ECS vs Self-Managed Kubernetes

Feature / Criteria	Amazon EKS (Elastic Kubernetes Service)	Amazon ECS (Elastic Container Service)	Self-Managed Kubernetes
Control Plane Management.	Fully managed by AWS.	Fully managed by AWS.	twtech manages everything
Orchestration Engine.	Kubernetes.	AWS-native (not Kubernetes)	Kubernetes
Standards & Portability.	Open-source, portable across clouds.	AWS-specific.	Fully portable
Ease of Use.	Moderate (Kubernetes complexity exists).	Easier (simplified abstractions)	Harder (install, upgrade, maintain)
Cost for Control Plane.	~$0.10/hour per cluster.	Free.	Varies (depends on setup)
Compute Options.	EC2, Fargate.	EC2, Fargate.	Any (EC2, on-prem, other cloud)
Networking.	VPC CNI plugin (pods get VPC IPs).	ENIs for tasks.	Depends on configuration
Logging & Monitoring.	CloudWatch, Fluent Bit, Prometheus, etc.	CloudWatch.	twtch configures and manage
Auto Scaling.	K8s HPA, Cluster Autoscaler, Karpenter.	ECS Service Auto Scaling.	Requires manual setup
Deployment Options.	Declarative YAML (kubectl, Helm, etc.)	JSON/YAML or AWS. console/API.	Declarative YAML (kubectl)
CI/CD Integration.	Works well with GitOps (e.g., ArgoCD)	Works well with CodePipeline, CodeDeploy.	Full control, more setup
Security (IAM/RBAC).	IAM + Kubernetes RBAC.	IAM roles/tasks.	Manual RBAC & cert management
Use Case Fit.	Complex microservices, multi-cloud.	Simpler AWS-native workloads.	Custom infra, full control

 When to Use Each

 Amazon EKS Cluster

• twtech needs Kubernetes, but want AWS to manage the control plane.
• twtech is already using Kubernetes-native tooling (Helm, ArgoCD, etc.).
• twtech wants portability or hybrid/multi-cloud.

 Amazon ECS Cluster

• twtech wants the easiest way to run containers on AWS.
• twtech doesn’t need Kubernetes complexity.
• twtech workloads are AWS-centric and can be tightly coupled to AWS services.

 Self-Managed Kubernetes Cluster

• twtech needs full control over everything (e.g., for compliance).
• Twtech is running on-prem, multi-cloud, or edge environments.
• twtech wants to experiment with low-level Kubernetes internals.