Kubernetes Node Image Management: Cross-CSP Analysis

# Kubernetes Node Image Management: Cross-CSP Analysis

**Scope**: AWS, GCP, Azure, Alibaba, Tencent, IBM, NCP, NHN image data

---

## Background

We discovered that images retrieved via AWS SDK cannot be directly used for K8s cluster node group creation ([Issue #2200](https://github.com/cloud-barista/cb-tumblebug/issues/2200)). This finding prompted a comprehensive investigation into whether other CSPs have similar constraints and how each CSP manages Kubernetes node images, with the goal of determining the appropriate K8s image API design for CB-Tumblebug.

---

## Key Findings

### 🎯 Major Discoveries

1. **AWS & GCP use type parameters instead of image IDs**
   - AWS: 260K images classified as `isKubernetesImage=true` in DB, but EKS API cannot use them directly
   - GCP: 3,358 images classified as K8s images, but 99.4% are Deprecated; `image-type` parameter recommended
   - **Conclusion**: For AWS/GCP, existing image API should return **type list** instead of stored image IDs

2. **Alibaba/Tencent/NHN directly specify VM images for automatic K8s node conversion**
   - No dedicated K8s images; accepts general VM images as input
   - CSP automatically installs kubelet and containerd
   - **Conclusion**: Existing image list API can be used as-is

3. **Azure/IBM/NCP do not allow image specification (fully automated)**
   - Users cannot select images
   - CSP automatically selects images matching Kubernetes version

### 💡 CB-Tumblebug Implementation Direction

```
GET /images?isKubernetesImage=true behavior change:

AWS/GCP:
├─ Do NOT return stored image IDs (260K for AWS, 3,358 for GCP)
└─ Return abstracted type lists instead:
    ├─ AWS: 11 ami-types (AL2023_x86_64_STANDARD, AL2_x86_64_GPU, etc.)
    └─ GCP: 6 image-types (COS_CONTAINERD, UBUNTU_CONTAINERD, etc.)

Alibaba/Tencent/NHN:
└─ ✅ Keep current approach (can use general VM images with isKubernetesImage=false)
```

---

## Core Difference: Image Specification Methods

**Summary**: Kubernetes node image specification methods differ completely across CSPs. AWS/GCP use abstracted type parameters, Alibaba /Tencent/NHN use specific image IDs, and Azure/IBM/NCP do not allow specification at all.

#### Detailed Comparison

| Item | AWS/GCP | Alibaba /Tencent/NHN |
|------|---------|---------------------|
| **Parameter Type** | Abstracted type name | Specific image ID |
| **Image Selection** | CSP auto-selects | User specifies directly |
| **Image Characteristics** | K8s pre-configured | General VM → K8s auto-conversion |
| **Auto Updates** | Possible when type unchanged | Requires image ID change |
| **Flexibility** | Low (type-constrained) | High (any VM image) |
| **Complexity** | Low (except AWS LT) | Low |

### Image Specification Examples

#### 🅰️ AWS & GCP: Abstracted Image Type Parameters

```bash
# AWS EKS
--ami-type AL2023_x86_64_STANDARD  # Type name → AWS auto-selects latest AMI

# GCP GKE  
--image-type COS_CONTAINERD  # Type name → Google auto-selects latest image
```

#### 🅱️ Alibaba, Tencent, NHN : Direct VM Image ID Specification

```bash
# Tencent TKE
--NodePoolOsCustomizeImage img-487zeit5  # General VM image ID

# NHN NKS
--image-id d18ef61d-xxx  # General VM image UUID

# Alibaba ACK
--image-id aliyun_4_x64_20G_container_optimized_xxx  # Image ID
```

---

## CSP-Specific Characteristics Summary

**Summary**: AWS has 260K images but EKS API only supports 11 types, and 99.4% of GCP images are Deprecated. Alibaba/Tencent/NHN automatically convert general VM images to K8s nodes.

### AWS EKS
- **Image Count**: 519,916
- **K8s Strategy**: Various official images (Auto Node, EKS-optimized, Worker, Ubuntu EKS, etc.)
- **⚠️ Critical**: All 266,107 K8s images are **EC2 AMIs** and **cannot be directly specified in EKS API**
  - EKS API has no parameter to directly input AMI ID
  - **All custom AMIs can only be used through Launch Template** (complex)
  - Images immediately usable: **0**
- **Recommended Approach**: Use `ami-type` parameter (AWS auto-selects AMI)
  - `AL2023_x86_64_STANDARD`: Amazon Linux 2023 (latest, recommended)
  - `AL2023_ARM_64_STANDARD`: Amazon Linux 2023 ARM
  - `AL2_x86_64`: Amazon Linux 2 (x86_64)
  - `AL2_x86_64_GPU`: Amazon Linux 2 GPU
  - `AL2_ARM_64`: Amazon Linux 2 (ARM64)
  - `BOTTLEROCKET_x86_64`, `BOTTLEROCKET_ARM_64`: Bottlerocket OS
  - `UBUNTU_20_04`, `UBUNTU_22_04`: Ubuntu LTS
  - `WINDOWS_CORE_2019`, `WINDOWS_FULL_2019`: Windows Server 2019
  - `WINDOWS_CORE_2022`, `WINDOWS_FULL_2022`: Windows Server 2022
  - `CUSTOM`: Custom AMI (requires Launch Template)
- **Characteristics**: Region-specific independent management, maximum flexibility, full customization via Launch Template

### GCP GKE
- **Image Count**: 10,702
- **K8s Strategy**: Single standard - Container-Optimized OS (COS)
- **⚠️ Critical**: **3,338 of 3,358 (99.4%) K8s images are Deprecated**
  - GKE API allows direct image URL specification (simpler than AWS)
  - **Technically usable** but **Deprecated means security patches stopped** (not recommended for production)
  - Even the 20 Available images are not recommended for direct specification (no auto-updates)
  - **Recommended**: Use `image-type` parameter (Google auto-selects and manages latest images)
- **Recommended Approach**: Use `image-type` parameter (Google auto-selects latest images)
  - `COS_CONTAINERD` (recommended): Container-Optimized OS with containerd
  - `COS`: Container-Optimized OS with Docker
  - `UBUNTU_CONTAINERD`: Ubuntu with containerd
  - `UBUNTU`: Ubuntu with Docker
  - `WINDOWS_LTSC`: Windows Server LTSC
  - `WINDOWS_SAC`: Windows Server SAC
- **Characteristics**: COS-centric, global unified management, aggressive version management, auto-updates

### Alibaba ACK
- **Image Count**: 354
- **K8s Strategy**: Provides 6 Container Optimized images
- **✅ Direct Use**: Can directly specify image ID in ACK API
  - 6 K8s-optimized images (recommended)
  - 348 general VM images also usable
  - All 354 images immediately available
- **Available Images**:
  - Container Optimized (recommended): `aliyun_*_container_optimized`
  - General images: CentOS, Ubuntu, Alibaba Cloud Linux, etc.
- **Characteristics**: High ARM support (19.2%), flexibility + optimization, no Launch Template required

### Tencent TKE
- **Image Count**: 100 (fewest)
- **K8s Strategy**: Auto-converts general VM images
- **✅ Direct Use**: 0 K8s-dedicated images, but **can directly specify general VM images in TKE API**
  - Select by image ID or OS type
  - TKE auto-converts to K8s nodes (installs kubelet, containerd)
  - All 100 images immediately available
- **Available Images**:
  - CentOS 7.x (most common, 22 images)
  - Ubuntu 22.04, 20.04, 18.04
  - Tencent Linux 2, 3 (proprietary distribution)
  - Debian 12, 10
  - Windows Server 2019, 2022, 2016
- **Characteristics**: CentOS-centric (42%), auto-conversion + flexibility, no Launch Template required

### NHN NKS
- **Image Count**: 127
- **K8s Strategy**: Auto-converts general VM images (similar to Tencent)
- **✅ Direct Use**: 0 K8s-dedicated images, but **can directly specify general VM images in NKS API**
  - Select by image UUID
  - NKS auto-converts to K8s nodes
  - All 127 images immediately available
- **Available Images**:
  - Ubuntu 22.04 (31 images, most common)
  - Windows 2016, 2019, 2022 (54 images total, 42.5%)
  - Rocky Linux 8, 9 (CentOS replacement)
  - Ubuntu 24.04 (latest LTS)
  - Debian 11, 9
- **Characteristics**: Very high Windows proportion (42.5%), Korea-focused (kr1, kr2 regions), no Launch Template required

---

## CB-Tumblebug Implementation Recommendations

### Priority 1: Use Recommended Approaches
```go
// AWS: Use ami-type (auto-selection, AL2023 recommended)
nodeGroup.AmiType = "AL2023_x86_64_STANDARD"

// GCP: Use image-type (auto-selection)
nodePool.Config.ImageType = "COS_CONTAINERD"

// Alibaba: Select Container Optimized
nodePool.NodeConfig.ImageId = "aliyun_4_x64_20G_container_optimized"
```

### Priority 2: Custom Images on User Request
```go
// AWS: Requires Launch Template creation (complex)
// GCP: Direct specification possible (need to distinguish Deprecated vs Available, security patch verification recommended)
// Alibaba/Tencent/NHN: Direct general image specification (auto K8s conversion)
// Azure/IBM/NCP: Not supported
```

---

## References

### AWS EKS
- [EKS CreateNodegroup API Reference](https://docs.aws.amazon.com/eks/latest/APIReference/API_CreateNodegroup.html)
- [EKS Managed Node Groups - AMI Types](https://docs.aws.amazon.com/eks/latest/userguide/launch-node-group.html)
- [EKS Optimized AMIs](https://docs.aws.amazon.com/eks/latest/userguide/eks-optimized-amis.html)

### GCP GKE  
- [GKE Node Images Overview](https://cloud.google.com/kubernetes-engine/docs/concepts/node-images)
- [GKE NodeConfig API Reference](https://cloud.google.com/kubernetes-engine/docs/reference/rest/v1/NodeConfig)
- [Container-Optimized OS Documentation](https://cloud.google.com/container-optimized-os/docs)
- [Compute Engine Image Deprecation](https://cloud.google.com/compute/docs/images/os-details#deprecation)

### Azure AKS
- [AKS Node Pool Management](https://learn.microsoft.com/en-us/azure/aks/manage-node-pools)
- [AKS Node Image Upgrade](https://learn.microsoft.com/en-us/azure/aks/node-image-upgrade)

### Alibaba ACK
- [ACK Node Pool Management](https://www.alibabacloud.com/help/en/ack/ack-managed-and-ack-dedicated/user-guide/manage-node-pools)
- [ACK Operating System Images](https://www.alibabacloud.com/help/en/ack/ack-managed-and-ack-dedicated/user-guide/use-an-os-image-provided-by-alibaba-cloud)

### Tencent TKE
- [TKE Node Pool API Reference](https://www.tencentcloud.com/document/product/457/36007)
- [TKE Operating System](https://www.tencentcloud.com/document/product/457/46750)

### NHN Cloud NKS
- [NKS User Guide](https://docs.nhncloud.com/en/Container/NKS/en/user-guide/)
- [NKS API Reference](https://docs.nhncloud.com/en/Container/NKS/en/api-guide/)

### Database
- CB-Tumblebug PostgreSQL Database: `image_infos` table (February 2026 data)
  - Image status (Available/Deprecated) based on metadata provided by each CSP API

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Kubernetes Node Image Management: Cross-CSP Analysis #2325

Kubernetes Node Image Management: Cross-CSP Analysis

Background

Key Findings

🎯 Major Discoveries

💡 CB-Tumblebug Implementation Direction

Core Difference: Image Specification Methods

Detailed Comparison

Image Specification Examples

🅰️ AWS & GCP: Abstracted Image Type Parameters

🅱️ Alibaba, Tencent, NHN : Direct VM Image ID Specification

CSP-Specific Characteristics Summary

AWS EKS

GCP GKE

Alibaba ACK

Tencent TKE

NHN NKS

CB-Tumblebug Implementation Recommendations

Priority 1: Use Recommended Approaches

Priority 2: Custom Images on User Request

References

AWS EKS

GCP GKE

Azure AKS

Alibaba ACK

Tencent TKE

NHN Cloud NKS

Database

Metadata

Assignees

Labels

Type

Fields

Projects

Milestone

Relationships

Development

Item	AWS/GCP	Alibaba /Tencent/NHN
Parameter Type	Abstracted type name	Specific image ID
Image Selection	CSP auto-selects	User specifies directly
Image Characteristics	K8s pre-configured	General VM → K8s auto-conversion
Auto Updates	Possible when type unchanged	Requires image ID change
Flexibility	Low (type-constrained)	High (any VM image)
Complexity	Low (except AWS LT)	Low

Kubernetes Node Image Management: Cross-CSP Analysis #2325

Description

Kubernetes Node Image Management: Cross-CSP Analysis

Background

Key Findings

🎯 Major Discoveries

💡 CB-Tumblebug Implementation Direction

Core Difference: Image Specification Methods

Detailed Comparison

Image Specification Examples

🅰️ AWS & GCP: Abstracted Image Type Parameters

🅱️ Alibaba, Tencent, NHN : Direct VM Image ID Specification

CSP-Specific Characteristics Summary

AWS EKS

GCP GKE

Alibaba ACK

Tencent TKE

NHN NKS

CB-Tumblebug Implementation Recommendations

Priority 1: Use Recommended Approaches

Priority 2: Custom Images on User Request

References

AWS EKS

GCP GKE

Azure AKS

Alibaba ACK

Tencent TKE

NHN Cloud NKS

Database

Metadata

Metadata

Assignees

Labels

Type

Fields

Projects

Milestone

Relationships

Development

Issue actions