HDDS-14558. [Recon] Show fs reserved space in datanodes page table under Storage Capacity

[priyeshkaratha]

What changes were proposed in this pull request?

On the Recon Datanode page, the Storage Capacity section currently displays Filesystem Capacity and Ozone Capacity. The difference between these two values represents the reserved space, but this is not explicitly shown, which can be confusing for users.

This pull request improves clarity by explicitly exposing the reserved space value. To achieve this, the existing datanode backend endpoint has been updated to return the correct reserved space, and the UI has been enhanced to display this value alongside the existing capacity metrics.

What is the link to the Apache JIRA

HDDS-14558

How was this patch tested?

Patch is tested manually

[ArafatKhan2198]

Hey @priyeshkaratha, thanks for the changes. Could you also document these updates in the Recon Swagger API and any other documentation that references or points to this report?

I think for the overview page as well we will have to document it.

[priyeshkaratha]

Thanks @ArafatKhan2198. I have filed https://issues.apache.org/jira/browse/HDDS-14594 for documentation update in Recon.

[devmadhuu]

Thanks @priyeshkaratha . Changes LGTM +1

[devabhishekpal]

Thanks for the reviews @devmadhuu @ArafatKhan2198.
Thanks for the improvement @priyeshkaratha.
LGTM, +1, merging this PR

[adoroszlai]

@devabhishekpal please feel free to remove Co-authored-by for insignificant contribution (merging master into the PR branch)

[devabhishekpal]

Sure, @adoroszlai I had missed that on this patch. We might have to revert this patch, will keep this in mind for the future.

[adoroszlai]

We might have to revert this patch

I don't think it should be reverted for this.