feat(metrics): added a gauge with version information

[cstockton]

This adds the 4 gauges seen below:

  # HELP global_auth_version_major Set to this auth servers major version number.
  # TYPE global_auth_version_major gauge
  global_auth_version_major{otel_scope_name="gotrue",otel_scope_version=""} 2

  # HELP global_auth_version_minor Set to this auth servers minor version number.
  # TYPE global_auth_version_minor gauge
  global_auth_version_minor{otel_scope_name="gotrue",otel_scope_version=""} 187

  # HELP global_auth_version_patch Set to this auth servers patch version number.
  # TYPE global_auth_version_patch gauge
  global_auth_version_patch{otel_scope_name="gotrue",otel_scope_version=""} 0

  # HELP global_auth_version_rc Set to this auth servers rc version number.
  # TYPE global_auth_version_rc gauge
  global_auth_version_rc{otel_scope_name="gotrue",otel_scope_version=""} 5

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

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📝 Walkthrough

Summary by CodeRabbit

• New Features
  • Version metrics are now collected and exposed, providing detailed version component information (major, minor, patch, release candidate) through observability platforms.

Walkthrough

The changes introduce a version metrics initialization system to internal/utilities/version.go, which exports the Version variable and InitVersionMetrics function. InitVersionMetrics parses semantic version information into major, minor, patch, and release candidate components, then creates OpenTelemetry gauge metrics for each component with bounds validation. The ConfigureMetrics function in internal/observability/metrics.go now calls InitVersionMetrics during metric setup. Comprehensive tests validate the semantic version parsing across multiple format variations and the complete initialization flow.

Sequence Diagram

sequenceDiagram
    actor ConfigureMetrics as metrics.ConfigureMetrics()
    participant InitVersionMetrics as utilities.InitVersionMetrics()
    participant ParseVersion as parseSemver()
    participant InitMetrics as initMetrics()
    participant Gauge as OTLP Gauges

    ConfigureMetrics->>InitVersionMetrics: ctx
    InitVersionMetrics->>ParseVersion: Version string
    alt ParseVersion succeeds
        ParseVersion-->>InitVersionMetrics: versionInfo{Major, Minor, Patch, RC}
    else ParseVersion fails
        ParseVersion-->>InitVersionMetrics: error (use empty versionInfo)
    end
    InitVersionMetrics->>InitMetrics: ctx, versionInfo
    InitMetrics->>Gauge: Create & record major gauge
    InitMetrics->>Gauge: Create & record minor gauge
    InitMetrics->>Gauge: Create & record patch gauge
    InitMetrics->>Gauge: Create & record rc gauge
    Gauge-->>InitMetrics: errors (if any)
    InitMetrics-->>InitVersionMetrics: aggregated errors
    InitVersionMetrics-->>ConfigureMetrics: error

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🚥 Pre-merge checks | ✅ 3 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: adding version information metrics. It directly reflects the core functionality introduced across the modified files.
Merge Conflict Detection	✅ Passed	✅ No merge conflicts detected when merging into master

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

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[coderabbitai]

Actionable comments posted: 2

🤖 Fix all issues with AI agents

In `@cmd/root_cmd.go`:
- Around line 56-59: The call to utilities.InitVersionMetrics(ctx) is ignoring
its returned error when config.Metrics.Enabled is true; capture the error and
handle it instead of discarding it. Update the block that checks
config.Metrics.Enabled to call err := utilities.InitVersionMetrics(ctx), then if
err != nil either return or wrap the error from the enclosing function (or log
it and exit) so failures are visible; reference the symbols
config.Metrics.Enabled and utilities.InitVersionMetrics(ctx) when making the
change.

In `@internal/utilities/version.go`:
- Around line 23-33: initVersionMetrics currently swallows parseSemver errors
and always returns nil, which hides malformed versions; change it to capture the
parse error from parseSemver(ver), still call initMetrics(ctx, vi) using a
zeroed vi when parse fails, and then return the original parse error (or a
wrapped error) if parseSemver returned one while still returning any initMetrics
error if that fails; reference parseSemver, initMetrics, initVersionMetrics, and
versionInfo to locate the changes.

🧹 Nitpick comments (1)

internal/utilities/version_test.go (1)

141-148: Improve the error assertion message for debuggability.

The current t.Fatalf("exp ") is truncated, making failures hard to diagnose.

🛠️ Suggested fix

 		if tc.err != "" {
 			if err == nil {
 				t.Fatal("exp non-nil err")
 			}
 			if exp, got := tc.err, err.Error(); !strings.Contains(got, exp) {
-				t.Fatalf("exp ")
+				t.Fatalf("exp error containing %q; got %q", exp, got)
 			}
 			continue
 		}

[jnschaeffer]

Out of curiosity, why have different gauges for each version number rather than a single label with a version string?

[cstockton]

Out of curiosity, why have different gauges for each version number rather than a single label with a version string?

I chose this because it sets maximum cardinality to 4 and I think it makes for better querying.

[coveralls]

Pull Request Test Coverage Report for Build 22100400863

Details

• 61 of 74 (82.43%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.05%) to 69.08%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
internal/observability/metrics.go	0	3	0.0%
internal/utilities/version.go	61	71	85.92%

Totals
Change from base Build 22075658585:	0.05%
Covered Lines:	15002
Relevant Lines:	21717

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💛 - Coveralls