Rename env to EC2_INSTANCE_TAG

[jongwooo]

Proposed changes:

Related issue litmuschaos/litmus#4807 (comment)

This PR fixes an issue where the ec2-stop-by-tag experiment fails to target the intended EC2 instance.

The ec2-stop-by-tag experiment encounters a TARGET_SELECTION_ERROR due to an incorrect retrieval of the EC2_INSTANCE_TAG environment variable.

Fault Summary:
TARGET_SELECTION_ERROR
{"errorCode":"TARGET_SELECTION_ERROR","phase":"PreChaos","reason":"failed to get the instance tag, invalid instance tag","target":"{EC2 Instance Tag: , Region: ap-northeast-2}"}

By correctly renaming the environment variable from INSTANCE_TAG to EC2_INSTANCE_TAG, we can accurately target the intended EC2 instance.

Types of changes:

What types of changes does your code introduce to Litmus? Put an x in the boxes that apply

• New feature (non-breaking change which adds functionality)
• Bugfix (non-breaking change which fixes an issue)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices applies)

Special notes for your reviewer:

cc. @namkyu1999

Checklist

• DCO signed
• Chart Version bumped
• Variables are documented in the README.md

[Jonsy13]

Hi @jongwooo ,

Lint Charts check is failing. For fixing the same, Bump the version to next patch (3.9.1). And then run helm-docs also in same directory.

Ref contributing guide for more details - https://github.com/litmuschaos/litmus-helm/blob/master/CONTRIBUTING.md

[Jonsy13]

Thanks @jongwooo , Just noticed that go runner image is also getting updated as part of this PR. Which means we first need to release go-runner. So now plan is lets wait till release of 3.10.0 which will have your fix. And then you can update your PR with 3.10.0 and then we can merge your PR.