[receiver/chrony] Enable re-aggregation feature (#47533)

#### Description
Enables dynamic metric reaggregation in the Chrony receiver. Collector
configuration files can now define a set of attributes per metric to
aggregate data by. This can be done for any metric attribute at a
[requirement
level](open-telemetry/opentelemetry-collector#13913)
of `recommended` or below.

For more information about how reaggregation works, see
open-telemetry/opentelemetry-collector#14281.

Changes:
- Set `reaggregation_enabled: true` in `metadata.yaml`
- Set `leap.status` attribute to `requirement_level: recommended`
- Ran `go generate ./...` to regenerate all derived files

#### Link to tracking issue
Fixes
#46350
Part of
#45396

#### Testing
- `go test -race ./...` in `receiver/chronyreceiver/` — all 27 tests
pass (including `reaggregate_set`)
- `go vet ./...` — clean
- `make chlog-validate` — valid

#### Documentation
No documentation changes needed. The generated `documentation.md` is
updated automatically by `go generate`.

Author: lazureykis

.chloggen/46350-chrony-enable-reaggregation.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: 'enhancement'
+
+# The name of the component, or a single word describing the area of concern, (e.g. receiver/filelog)
+component: receiver/chrony
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Enables dynamic metric reaggregation in the Chrony receiver. This does not break existing configuration files.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [46350]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user, api]

receiver/chronyreceiver/factory_test.go

@@ -35,14 +35,13 @@ func TestCreatingMetricsReceiver(t *testing.T) {
 
 	factory := NewFactory()
 	mbc := metadata.DefaultMetricsBuilderConfig()
-	mbc.Metrics = metadata.MetricsConfig{
-		NtpTimeCorrection: metadata.MetricConfig{
-			Enabled: true,
-		},
-		NtpSkew: metadata.MetricConfig{
-			Enabled: true,
-		},
-	}
+	mbc.Metrics.NtpFrequencyOffset.Enabled = false
+	mbc.Metrics.NtpSkew.Enabled = true
+	mbc.Metrics.NtpStratum.Enabled = false
+	mbc.Metrics.NtpTimeCorrection.Enabled = true
+	mbc.Metrics.NtpTimeLastOffset.Enabled = false
+	mbc.Metrics.NtpTimeRmsOffset.Enabled = false
+	mbc.Metrics.NtpTimeRootDelay.Enabled = false
 	mem, err := factory.CreateMetrics(
 		t.Context(),
 		receivertest.NewNopSettings(metadata.Type),

receiver/chronyreceiver/internal/metadata/config.schema.yaml

@@ -11,6 +11,22 @@ $defs:
           enabled:
             type: boolean
             default: false
+          aggregation_strategy:
+            type: string
+            enum:
+              - "sum"
+              - "avg"
+              - "min"
+              - "max"
+            default: "avg"
+          attributes:
+            type: array
+            items:
+              type: string
+              enum:
+                - "leap.status"
+            default:
+              - "leap.status"
       ntp.skew:
         description: "NtpSkewMetricConfig provides config for the ntp.skew metric."
         type: object
@@ -32,27 +48,91 @@ $defs:
           enabled:
             type: boolean
             default: true
+          aggregation_strategy:
+            type: string
+            enum:
+              - "sum"
+              - "avg"
+              - "min"
+              - "max"
+            default: "avg"
+          attributes:
+            type: array
+            items:
+              type: string
+              enum:
+                - "leap.status"
+            default:
+              - "leap.status"
       ntp.time.last_offset:
         description: "NtpTimeLastOffsetMetricConfig provides config for the ntp.time.last_offset metric."
         type: object
         properties:
           enabled:
             type: boolean
             default: true
+          aggregation_strategy:
+            type: string
+            enum:
+              - "sum"
+              - "avg"
+              - "min"
+              - "max"
+            default: "avg"
+          attributes:
+            type: array
+            items:
+              type: string
+              enum:
+                - "leap.status"
+            default:
+              - "leap.status"
       ntp.time.rms_offset:
         description: "NtpTimeRmsOffsetMetricConfig provides config for the ntp.time.rms_offset metric."
         type: object
         properties:
           enabled:
             type: boolean
             default: false
+          aggregation_strategy:
+            type: string
+            enum:
+              - "sum"
+              - "avg"
+              - "min"
+              - "max"
+            default: "avg"
+          attributes:
+            type: array
+            items:
+              type: string
+              enum:
+                - "leap.status"
+            default:
+              - "leap.status"
       ntp.time.root_delay:
         description: "NtpTimeRootDelayMetricConfig provides config for the ntp.time.root_delay metric."
         type: object
         properties:
           enabled:
             type: boolean
             default: false
+          aggregation_strategy:
+            type: string
+            enum:
+              - "sum"
+              - "avg"
+              - "min"
+              - "max"
+            default: "avg"
+          attributes:
+            type: array
+            items:
+              type: string
+              enum:
+                - "leap.status"
+            default:
+              - "leap.status"
   metrics_builder_config:
     description: MetricsBuilderConfig is a configuration for chrony metrics builder.
     type: object