Inaccurate instance type selection

Oct 13, 2025 by wbrum.org 0 views

Introduction

Amazon Elastic Container Service for Kubernetes (EKS) is a managed container orchestration service that makes it easy to deploy, manage, and scale containerized applications. Rancher is a popular container management platform that provides a user-friendly interface for managing EKS clusters. However, users have reported an issue where the Rancher UI is not loading the exact instance type for EKS Node Group with a custom Launch Template (LT). In this article, we will delve into the details of this issue and explore possible solutions.

Setup

Rancher version: The issue was reported in Rancher version 2.10.2.
Rancher UI Extensions: The user had installed the necessary extensions for EKS support.
Browser type & version: The issue was encountered on a specific browser version, but the exact version is not specified.

Describe the Bug

The issue arises when there is a problem with the network requests to AWS for the NodeGroup component. In such cases, the errors are not displayed to the user on the interface CruEKS. This can lead to a situation where the user is unaware of the problem, and the provision cluster interface might not work properly.

To Reproduce

The issue seems to be related to the way Rancher pulls all versions of the Launch Template. If one version is missing, it can cause issues. To reproduce the problem, the user deleted version #1 of the Launch Template and observed the response error to the DescribeLaunchTemplateVersions API request when selecting the Launch Template in the Rancher UI.

<Response><Errors><Error><Code>InvalidLaunchTemplateId.VersionNotFound</Code><Message>Could not find the specified version 1 for the launch template with ID lt-0865b59493c8f9530.</Message></Error></Errors><RequestID>d6ac4c5f-7de6-433a-b6d4-461aad1a40e5</RequestID></Response>

Result

The user is unaware of the problem, which can lead to a range of issues, including:

Inaccurate instance type selection: The user may select an incorrect instance type, which can affect the performance and scalability of their EKS cluster.
Provision cluster interface issues: The provision cluster interface may not work properly, leading to delays and frustration for the user.
Increased risk of errors: The user may be unaware of potential errors, which can increase the risk of errors and downtime for their EKS cluster.

Expected Result

We should surface those errors to the user, providing them with a clear understanding of the issue and the necessary steps to resolve it. This can be achieved by displaying the errors on the interface CruEKS and providing a clear and concise message to the user.

Screenshots

No screenshots are provided, but the issue can be visualized as follows:

Rancher UI: The Rancher UI displays the NodeGroup component, but with an error message indicating that the instance type is not available.
AWS Console: The AWS Console displays the error message indicating that the specified version of the Launch Template is not found.

Additional Context

The issue is related to the SURE-9825 bug, which is a known issue in the Rancher community. The bug is related to the way Rancher pulls all versions of the Launch Template, and the issue can be reproduced by deleting version #1 of the Launch Template.

Conclusion

In conclusion, the EKS - Rancher UI not loading exact instance type for EKS Node Group with custom LT is a known issue in the Rancher community. The issue arises when there is a problem with the network requests to AWS for the NodeGroup component, and the errors are not displayed to the user on the interface CruEKS. To resolve this issue, we should surface those errors to the user, providing them with a clear understanding of the issue and the necessary steps to resolve it.

Recommendations

Based on the analysis of the issue, the following recommendations are made:

Display errors on the interface: The errors should be displayed on the interface CruEKS to provide the user with a clear understanding of the issue.
Provide clear and concise message: A clear and concise message should be provided to the user, indicating the issue and the necessary steps to resolve it.
Improve network requests: The network requests to AWS should be improved to reduce the likelihood of errors and ensure that the instance type is loaded correctly.

Introduction

In our previous article, we discussed the issue of EKS - Rancher UI not loading exact instance type for EKS Node Group with custom LT. In this article, we will provide a Q&A section to address some of the frequently asked questions related to this issue.

Q: What is the root cause of this issue?

A: The root cause of this issue is related to the way Rancher pulls all versions of the Launch Template. If one version is missing, it can cause issues with the instance type loading.

Q: How can I reproduce this issue?

A: To reproduce this issue, you can delete version #1 of the Launch Template and observe the response error to the DescribeLaunchTemplateVersions API request when selecting the Launch Template in the Rancher UI.

Q: What are the consequences of this issue?

A: The consequences of this issue can include:

Inaccurate instance type selection: The user may select an incorrect instance type, which can affect the performance and scalability of their EKS cluster.
Provision cluster interface issues: The provision cluster interface may not work properly, leading to delays and frustration for the user.
Increased risk of errors: The user may be unaware of potential errors, which can increase the risk of errors and downtime for their EKS cluster.

Q: How can I resolve this issue?

A: To resolve this issue, you can try the following:

Display errors on the interface: The errors should be displayed on the interface CruEKS to provide the user with a clear understanding of the issue.
Provide clear and concise message: A clear and concise message should be provided to the user, indicating the issue and the necessary steps to resolve it.
Improve network requests: The network requests to AWS should be improved to reduce the likelihood of errors and ensure that the instance type is loaded correctly.

Q: Is this issue specific to EKS or can it affect other services as well?

A: This issue is specific to EKS, but it can affect other services that use Launch Templates and instance types.

Q: Can I prevent this issue from occurring in the future?

A: Yes, you can prevent this issue from occurring in the future by:

Regularly checking the Launch Template versions: Regularly checking the Launch Template versions can help you identify any missing versions and prevent issues.
Improving network requests: Improving network requests to AWS can reduce the likelihood of errors and ensure that the instance type is loaded correctly.
Using a more robust Launch Template management system: Using a more robust Launch Template management system can help you manage Launch Templates and instance types more effectively and prevent issues.

Q: What is the current status of this issue?

A: The current status of this issue is that it is a known issue in the Rancher community, and a fix is being worked on. In the meantime, users can try the recommended solutions to resolve the issue.

Conclusion

In conclusion, the EKS - Rancher UI not loading exact instance type for EKS Node Group with custom LT is a known issue in the Rancher community. By understanding the root cause of the issue, reproducing it, and resolving it, users can improve their user experience and reduce the risk of errors and downtime for their EKS clusters.