Migrate from IMDSv1 to IMDSv2

[Himtanaya]

Issue #, if available:
N/A

Description of changes:
IMDSv2 uses session authentication to retrieve EC2 instance metadata.
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/configuring-instance-metadata-service.html

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[waifa]

Looks like code build for your latest commit is failing?

[Himtanaya]

Build for the last commit passed. Can you refresh maybe you are not seeing the latest commit or it's possible GitHub is not updating build status.

[waifa]

Can we remove those two "Fix flake8 issues" commits? They don't seem to be adding anything substantial/relevant to this PR. If they are needed you can squash them into one commit to keep our commits clean.

[Himtanaya]

Can we remove those two "Fix flake8 issues" commits? They don't seem to be adding anything substantial/relevant to this PR. If they are needed you can squash them into one commit to keep our commits clean.

I am going to squash and merge, so there will be only one commit.

[evanuk]

👍

[hussam789]

PR Code Suggestions ✨

Category	Suggestion	Impact
Possible issue	Check HTTP response status The fetchString function should check the HTTP status code before returning the response text. If the status code indicates an error, the function should raise an exception to properly handle failure cases. aws_embedded_metrics/environment/ec2_environment.py [48-52] async def fetchString( session: aiohttp.ClientSession, method: str, url: str, headers: Dict[str, str] ) -> str: async with session.request(method, url, timeout=2, headers=headers) as response: + response.raise_for_status() return await response.text() Apply this suggestion Suggestion importance[1-10]: 8 __ Why: This suggestion enhances error handling in the fetchString function by ensuring that HTTP error responses raise exceptions before processing the body, which improves robustness without altering the core functionality.	Medium
	Validate HTTP response status Similar to the fetchString function, fetchJSON should check the HTTP status code before processing the response to ensure proper error handling. aws_embedded_metrics/environment/ec2_environment.py [38-45] async def fetchJSON( session: aiohttp.ClientSession, method: str, url: str, headers: Dict[str, str], ) -> Dict[str, Any]: async with session.request(method, url, timeout=2, headers=headers) as response: + response.raise_for_status() # content_type=None prevents validation of the HTTP Content-Type header # The EC2 metadata endpoint uses text/plain instead of application/json # https://github.com/aio-libs/aiohttp/blob/7f777333a4ec0043ddf2e8d67146a626089773d9/aiohttp/web_request.py#L582-L585 return cast(Dict[str, Any], await response.json(content_type=None)) Apply this suggestion Suggestion importance[1-10]: 8 __ Why: By adding a status check using response.raise_for_status() in fetchJSON, this suggestion ensures that any HTTP errors are caught early, aligning error handling consistently with similar improvements and enhancing overall reliability.	Medium
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