fix: updates for tsdb blocks handling

[tjhop]

Two small fixes:

• I forgot the implementation for *apiClientImpl.Do() already extracts
  the response content from the enveloped data field in the response,
  so the wrapper struct isn't needed here.
• The compaction section of a block has an optional parents field
  for tracking block lineage in deeper compaction levels. This slipped
  my mind during implementation because I was looking at the example API
  response on the API docs, which use a mock response with a single block
  that is uncompacted.

I noticed these while working on tjhop/prometheus-mcp-server#77

Signed-off-by: TJ Hoplock t.hoplock@gmail.com

[kakkoyun]

Considering these issues slipped through the cracks, I would really appreciate if you could add more comprehensive tests so that we prevent similar future issues.

Thanks in advance 🙏

[tjhop]

That's fair, I can expand tests.

Ideally, it would be simpler to just import prometheus itself as a library and use the types already defined for these in prometheus. That would obviously help to keep things in sync and benefit from existing testing there. It becomes a bit awkward though, since prometheus itself also imports the client_golang library (mostly for implementing metrics) and so we'd be importing ourselves and nearing a circular import. It would also blow up dependencies, and I know this library is already heavily used/strictly watched for deps.

Perhaps this is a situation where a little bit of copying is better than a little bit of dependency?

[tjhop]

Both of the checks that are failing are for TestGoCollectorAllowList which is unrelated to this PR, so I think we should be good?

@kakkoyun sorry it's been a bit -- if you get some more time, I'd appreciate some fresh eyes please!