Fix/prometheus metadata sorting

[Sinscerly]

Description

This PR adds Prometheus metadata to all metrics types. Therefor Prometheus can include the TYPE and HELP information when scraping the endpoint.

See more details in #12110.

Fixes: #12110

Types of changes

• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] Enhancement (improves an existing feature and functionality)
• [ ] Cleanup (Code refactoring and cleanup, that may add test cases)
• [ ] Build/CI
• [ ] Test (unit or integration test code)

Feature/Enhancement Scale or Bug Severity

Feature/Enhancement Scale

• [ ] Major
• [x] Minor

Bug Severity

• [ ] BLOCKER
• [ ] Critical
• [ ] Major
• [x] Minor
• [ ] Trivial

Screenshots (if appropriate):

How Has This Been Tested?

I've tested the code change with a simplistic setup (didn't got all running, @abh1sar could you test it together more fully with your extra Prometheus metrics as my dev environment is still not working correctly) I've successfully seen that the TYPE and HELP information is added to the nicely sorted list of metrics the exporter provides.

How did you try to break this feature and the system with this change?

I've enabled the Prometheus exporter and queried the endpoint multiple times to see the data came out like this:

# Cloudstack Prometheus Metrics
# HELP cloudstack_domain_limit_cpu_cores_total Total CPU core limit across all domains
# TYPE cloudstack_domain_limit_cpu_cores_total gauge
cloudstack_domain_limit_cpu_cores_total 0
# HELP cloudstack_domain_limit_memory_mibs_total Total memory limit in MiB across all domains
# TYPE cloudstack_domain_limit_memory_mibs_total gauge
cloudstack_domain_limit_memory_mibs_total 0
# HELP cloudstack_domain_resource_count Resource usage count per domain
# TYPE cloudstack_domain_resource_count gauge
cloudstack_domain_resource_count{domain="/", type="memory"} 0
cloudstack_domain_resource_count{domain="/", type="cpu"} 0
cloudstack_domain_resource_count{domain="/", type="gpu"} 0
cloudstack_domain_resource_count{domain="/", type="primary_storage"} 0

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[DaanHoogland]

@blueorangutan package

[blueorangutan]

@DaanHoogland a [SL] Jenkins job has been kicked to build packages. It will be bundled with KVM, XenServer and VMware SystemVM templates. I'll keep you posted as I make progress.

[codecov[bot]]

Codecov Report

:x: Patch coverage is 0% with 43 lines in your changes missing coverage. Please review. :white_check_mark: Project coverage is 17.56%. Comparing base (6dc259c) to head (8851dd9).

Files with missing lines	Patch %	Lines
...che/cloudstack/metrics/PrometheusExporterImpl.java	0.00%	43 Missing :warning:

Additional details and impacted files

@@            Coverage Diff            @@
##               main   #12112   +/-   ##
=========================================
  Coverage     17.55%   17.56%           
- Complexity    15535    15541    +6     
=========================================
  Files          5911     5911           
  Lines        529359   529377   +18     
  Branches      64655    64656    +1     
=========================================
+ Hits          92949    92993   +44     
+ Misses       425952   425924   -28     
- Partials      10458    10460    +2     

Flag	Coverage Δ
uitests	3.58% <ø> (ø)
unittests	18.63% <0.00%> (+<0.01%)	:arrow_up:

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[blueorangutan]

Packaging result [SF]: ✔️ el8 ✔️ el9 ✔️ el10 ✔️ debian ✔️ suse15. SL-JID 15807

[DaanHoogland]

@blueorangutan test

[blueorangutan]

@DaanHoogland a [SL] Trillian-Jenkins test job (ol8 mgmt + kvm-ol8) has been kicked to run smoke tests

[blueorangutan]

[SF] Trillian Build Failed (tid-14851)

[blueorangutan]

[SF] Trillian Build Failed (tid-14866)

[blueorangutan]

[SF] Trillian test result (tid-14870) Environment: kvm-ol8 (x2), zone: Advanced Networking with Mgmt server ol8 Total time taken: 49860 seconds Marvin logs: https://github.com/blueorangutan/acs-prs/releases/download/trillian/pr12112-t14870-kvm-ol8.zip Smoke tests completed. 150 look OK, 0 have errors, 0 did not run Only failed and skipped tests results shown below:

Test	Result	Time (s)	Test File

[DaanHoogland]

@kiranchavala @NuxRo , can you guys have a look at this?

[DaanHoogland]

@Sinscerly , given comment https://github.com/apache/cloudstack/pull/12112#discussion_r2618715937, will you work on this more or do you want this merged as is? cc @kiranchavala @NuxRo @nvazquez