[connector/routing] Support metric routing

.chloggen/routing-by-metrics.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. filelogreceiver)
+component: routingconnector
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Add ability to route by metric context
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [36236]
+
+# (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: []

connector/routingconnector/README.md

@@ -33,7 +33,7 @@ If you are not already familiar with connectors, you may find it helpful to firs
 The following settings are available:
 
 - `table (required)`: the routing table for this connector.
-- `table.context (optional, default: resource)`: the [OTTL Context] in which the statement will be evaluated. Currently, only `resource`, `log`, and `request` are supported.
+- `table.context (optional, default: resource)`: the [OTTL Context] in which the statement will be evaluated. Currently, only `resource`, `metric`, `log`, and `request` are supported.
 - `table.statement`: the routing condition provided as the [OTTL] statement. Required if `table.condition` is not provided. May not be used for `request` context.
 - `table.condition`: the routing condition provided as the [OTTL] condition. Required if `table.statement` is not provided. Required for `request` context.
 - `table.pipelines (required)`: the list of pipelines to use when the routing condition is met.
@@ -43,7 +43,7 @@ The following settings are available:
 
 ### Limitations
 
-- The `match_once` setting is only supported when using the `resource` context. If any routes use `log` or `request` context, `match_once` must be set to `true`.
+- The `match_once` setting is only supported when using the `resource` context. If any routes use `metric`, `log` or `request` context, `match_once` must be set to `true`.
 - The `request` context requires use of the `condition` setting, and relies on a very limited grammar. Conditions must be in the form of `request["key"] == "value"` or `request["key"] != "value"`. (In the future, this grammar may be expanded to support more complex conditions.)
 
 ### Supported [OTTL] functions

connector/routingconnector/config.go

@@ -77,7 +77,7 @@ func (c *Config) Validate() error {
 				return err
 			}
 			fallthrough
-		case "log": // ok
+		case "metric", "log": // ok
 			if !c.MatchOnce {
 				return fmt.Errorf(`%q context is not supported with "match_once: false"`, item.Context)
 			}

connector/routingconnector/config_test.go

@@ -218,6 +218,22 @@ func TestValidateConfig(t *testing.T) {
 			},
 			error: "invalid context: invalid",
 		},
+		{
+			name: "metric context with match_once false",
+			config: &Config{
+				MatchOnce: false,
+				Table: []RoutingTableItem{
+					{
+						Context:   "metric",
+						Statement: `route() where attributes["attr"] == "acme"`,
+						Pipelines: []pipeline.ID{
+							pipeline.NewIDWithName(pipeline.SignalTraces, "otlp"),
+						},
+					},
+				},
+			},
+			error: `"metric" context is not supported with "match_once: false"`,
+		},
 		{
 			name: "log context with match_once false",
 			config: &Config{

connector/routingconnector/internal/pmetricutil/metrics.go

@@ -16,3 +16,46 @@ func MoveResourcesIf(from, to pmetric.Metrics, f func(pmetric.ResourceMetrics) b
 		return true
 	})
 }
+
+// MoveMetricsWithContextIf calls f sequentially for each Metric present in the first pmetric.Metrics.
+// If f returns true, the element is removed from the first pmetric.Metrics and added to the second pmetric.Metrics.
+// Notably, the Resource and Scope associated with the Metric are created in the second pmetric.Metrics only once.
+// Resources or Scopes are removed from the original if they become empty. All ordering is preserved.
+func MoveMetricsWithContextIf(from, to pmetric.Metrics, f func(pmetric.ResourceMetrics, pmetric.ScopeMetrics, pmetric.Metric) bool) {
+	rms := from.ResourceMetrics()
+	for i := 0; i < rms.Len(); i++ {
+		rm := rms.At(i)
+		sms := rm.ScopeMetrics()
+		var rmCopy *pmetric.ResourceMetrics
+		for j := 0; j < sms.Len(); j++ {
+			sm := sms.At(j)
+			ms := sm.Metrics()
+			var smCopy *pmetric.ScopeMetrics
+			ms.RemoveIf(func(m pmetric.Metric) bool {
+				if !f(rm, sm, m) {
+					return false
+				}
+				if rmCopy == nil {
+					rmc := to.ResourceMetrics().AppendEmpty()
+					rmCopy = &rmc
+					rm.Resource().CopyTo(rmCopy.Resource())
+					rmCopy.SetSchemaUrl(rm.SchemaUrl())
+				}
+				if smCopy == nil {
+					smc := rmCopy.ScopeMetrics().AppendEmpty()
+					smCopy = &smc
+					sm.Scope().CopyTo(smCopy.Scope())
+					smCopy.SetSchemaUrl(sm.SchemaUrl())
+				}
+				m.CopyTo(smCopy.Metrics().AppendEmpty())
+				return true
+			})
+		}
+		sms.RemoveIf(func(sm pmetric.ScopeMetrics) bool {
+			return sm.Metrics().Len() == 0
+		})
+	}
+	rms.RemoveIf(func(rm pmetric.ResourceMetrics) bool {
+		return rm.ScopeMetrics().Len() == 0
+	})
+}

connector/routingconnector/internal/pmetricutil/metrics_test.go

@@ -80,3 +80,147 @@ func TestMoveResourcesIf(t *testing.T) {
 		})
 	}
 }
+
+func TestMoveMetricsWithContextIf(t *testing.T) {
+	testCases := []struct {
+		name       string
+		moveIf     func(pmetric.ResourceMetrics, pmetric.ScopeMetrics, pmetric.Metric) bool
+		from       pmetric.Metrics
+		to         pmetric.Metrics
+		expectFrom pmetric.Metrics
+		expectTo   pmetric.Metrics
+	}{
+		{
+			name: "move_none",
+			moveIf: func(_ pmetric.ResourceMetrics, _ pmetric.ScopeMetrics, _ pmetric.Metric) bool {
+				return false
+			},
+			from:       pmetricutiltest.NewMetrics("AB", "CD", "EF", "GH"),
+			to:         pmetric.NewMetrics(),
+			expectFrom: pmetricutiltest.NewMetrics("AB", "CD", "EF", "GH"),
+			expectTo:   pmetric.NewMetrics(),
+		},
+		{
+			name: "move_all",
+			moveIf: func(_ pmetric.ResourceMetrics, _ pmetric.ScopeMetrics, _ pmetric.Metric) bool {
+				return true
+			},
+			from:       pmetricutiltest.NewMetrics("AB", "CD", "EF", "GH"),
+			to:         pmetric.NewMetrics(),
+			expectFrom: pmetric.NewMetrics(),
+			expectTo:   pmetricutiltest.NewMetrics("AB", "CD", "EF", "GH"),
+		},
+		{
+			name: "move_all_from_one_resource",
+			moveIf: func(rl pmetric.ResourceMetrics, _ pmetric.ScopeMetrics, _ pmetric.Metric) bool {
+				rname, ok := rl.Resource().Attributes().Get("resourceName")
+				return ok && rname.AsString() == "resourceB"
+			},
+			from:       pmetricutiltest.NewMetrics("AB", "CD", "EF", "GH"),
+			to:         pmetric.NewMetrics(),
+			expectFrom: pmetricutiltest.NewMetrics("A", "CD", "EF", "GH"),
+			expectTo:   pmetricutiltest.NewMetrics("B", "CD", "EF", "GH"),
+		},
+		{
+			name: "move_all_from_one_scope",
+			moveIf: func(rl pmetric.ResourceMetrics, sl pmetric.ScopeMetrics, _ pmetric.Metric) bool {
+				rname, ok := rl.Resource().Attributes().Get("resourceName")
+				return ok && rname.AsString() == "resourceB" && sl.Scope().Name() == "scopeC"
+			},
+			from: pmetricutiltest.NewMetrics("AB", "CD", "EF", "GH"),
+			to:   pmetric.NewMetrics(),
+			expectFrom: pmetricutiltest.NewMetricsFromOpts(
+				pmetricutiltest.WithResource('A',
+					pmetricutiltest.WithScope('C', pmetricutiltest.WithMetric('E', "GH"), pmetricutiltest.WithMetric('F', "GH")),
+					pmetricutiltest.WithScope('D', pmetricutiltest.WithMetric('E', "GH"), pmetricutiltest.WithMetric('F', "GH")),
+				),
+				pmetricutiltest.WithResource('B',
+					pmetricutiltest.WithScope('D', pmetricutiltest.WithMetric('E', "GH"), pmetricutiltest.WithMetric('F', "GH")),
+				),
+			),
+			expectTo: pmetricutiltest.NewMetrics("B", "C", "EF", "GH"),
+		},
+		{
+			name: "move_all_from_one_scope_in_each_resource",
+			moveIf: func(_ pmetric.ResourceMetrics, sl pmetric.ScopeMetrics, _ pmetric.Metric) bool {
+				return sl.Scope().Name() == "scopeD"
+			},
+			from:       pmetricutiltest.NewMetrics("AB", "CD", "EF", "GH"),
+			to:         pmetric.NewMetrics(),
+			expectFrom: pmetricutiltest.NewMetrics("AB", "C", "EF", "GH"),
+			expectTo:   pmetricutiltest.NewMetrics("AB", "D", "EF", "GH"),
+		},
+		{
+			name: "move_one",
+			moveIf: func(rl pmetric.ResourceMetrics, sl pmetric.ScopeMetrics, m pmetric.Metric) bool {
+				rname, ok := rl.Resource().Attributes().Get("resourceName")
+				return ok && rname.AsString() == "resourceA" && sl.Scope().Name() == "scopeD" && m.Name() == "metricF"
+			},
+			from: pmetricutiltest.NewMetrics("AB", "CD", "EF", "GH"),
+			to:   pmetric.NewMetrics(),
+			expectFrom: pmetricutiltest.NewMetricsFromOpts(
+				pmetricutiltest.WithResource('A',
+					pmetricutiltest.WithScope('C', pmetricutiltest.WithMetric('E', "GH"), pmetricutiltest.WithMetric('F', "GH")),
+					pmetricutiltest.WithScope('D', pmetricutiltest.WithMetric('E', "GH")),
+				),
+				pmetricutiltest.WithResource('B',
+					pmetricutiltest.WithScope('C', pmetricutiltest.WithMetric('E', "GH"), pmetricutiltest.WithMetric('F', "GH")),
+					pmetricutiltest.WithScope('D', pmetricutiltest.WithMetric('E', "GH"), pmetricutiltest.WithMetric('F', "GH")),
+				),
+			),
+			expectTo: pmetricutiltest.NewMetrics("A", "D", "F", "GH"),
+		},
+		{
+			name: "move_one_from_each_scope",
+			moveIf: func(_ pmetric.ResourceMetrics, _ pmetric.ScopeMetrics, m pmetric.Metric) bool {
+				return m.Name() == "metricE"
+			},
+			from:       pmetricutiltest.NewMetrics("AB", "CD", "EF", "GH"),
+			to:         pmetric.NewMetrics(),
+			expectFrom: pmetricutiltest.NewMetrics("AB", "CD", "F", "GH"),
+			expectTo:   pmetricutiltest.NewMetrics("AB", "CD", "E", "GH"),
+		},
+		{
+			name: "move_one_from_each_scope_in_one_resource",
+			moveIf: func(rl pmetric.ResourceMetrics, _ pmetric.ScopeMetrics, m pmetric.Metric) bool {
+				rname, ok := rl.Resource().Attributes().Get("resourceName")
+				return ok && rname.AsString() == "resourceB" && m.Name() == "metricE"
+			},
+			from: pmetricutiltest.NewMetrics("AB", "CD", "EF", "GH"),
+			to:   pmetric.NewMetrics(),
+			expectFrom: pmetricutiltest.NewMetricsFromOpts(
+				pmetricutiltest.WithResource('A',
+					pmetricutiltest.WithScope('C', pmetricutiltest.WithMetric('E', "GH"), pmetricutiltest.WithMetric('F', "GH")),
+					pmetricutiltest.WithScope('D', pmetricutiltest.WithMetric('E', "GH"), pmetricutiltest.WithMetric('F', "GH")),
+				),
+				pmetricutiltest.WithResource('B',
+					pmetricutiltest.WithScope('C', pmetricutiltest.WithMetric('F', "GH")),
+					pmetricutiltest.WithScope('D', pmetricutiltest.WithMetric('F', "GH")),
+				),
+			),
+			expectTo: pmetricutiltest.NewMetrics("B", "CD", "E", "GH"),
+		},
+		{
+			name: "move_some_to_preexisting",
+			moveIf: func(_ pmetric.ResourceMetrics, sl pmetric.ScopeMetrics, _ pmetric.Metric) bool {
+				return sl.Scope().Name() == "scopeD"
+			},
+			from:       pmetricutiltest.NewMetrics("AB", "CD", "EF", "GH"),
+			to:         pmetricutiltest.NewMetrics("1", "2", "3", "4"),
+			expectFrom: pmetricutiltest.NewMetrics("AB", "C", "EF", "GH"),
+			expectTo: pmetricutiltest.NewMetricsFromOpts(
+				pmetricutiltest.WithResource('1', pmetricutiltest.WithScope('2', pmetricutiltest.WithMetric('3', "4"))),
+				pmetricutiltest.WithResource('A', pmetricutiltest.WithScope('D', pmetricutiltest.WithMetric('E', "GH"), pmetricutiltest.WithMetric('F', "GH"))),
+				pmetricutiltest.WithResource('B', pmetricutiltest.WithScope('D', pmetricutiltest.WithMetric('E', "GH"), pmetricutiltest.WithMetric('F', "GH"))),
+			),
+		},
+	}
+
+	for _, tt := range testCases {
+		t.Run(tt.name, func(t *testing.T) {
+			pmetricutil.MoveMetricsWithContextIf(tt.from, tt.to, tt.moveIf)
+			assert.NoError(t, pmetrictest.CompareMetrics(tt.expectFrom, tt.from), "from not modified as expected")
+			assert.NoError(t, pmetrictest.CompareMetrics(tt.expectTo, tt.to), "to not as expected")
+		})
+	}
+}

connector/routingconnector/internal/pmetricutiltest/metrics.go

@@ -43,3 +43,59 @@ func NewMetrics(resourceIDs, scopeIDs, metricIDs, dataPointIDs string) pmetric.M
 	}
 	return md
 }
+
+type Resource struct {
+	id     byte
+	scopes []Scope
+}
+
+type Scope struct {
+	id      byte
+	metrics []Metric
+}
+
+type Metric struct {
+	id         byte
+	dataPoints string
+}
+
+func WithResource(id byte, scopes ...Scope) Resource {
+	r := Resource{id: id}
+	r.scopes = append(r.scopes, scopes...)
+	return r
+}
+
+func WithScope(id byte, metrics ...Metric) Scope {
+	s := Scope{id: id}
+	s.metrics = append(s.metrics, metrics...)
+	return s
+}
+
+func WithMetric(id byte, dataPoints string) Metric {
+	return Metric{id: id, dataPoints: dataPoints}
+}
+
+// NewMetricsFromOpts creates a pmetric.Metrics with the specified resources, scopes, metrics,
+// and data points. The general idea is the same as NewMetrics, but this function allows for
+// more flexibility in creating non-uniform structures.
+func NewMetricsFromOpts(resources ...Resource) pmetric.Metrics {
+	md := pmetric.NewMetrics()
+	for _, resource := range resources {
+		r := md.ResourceMetrics().AppendEmpty()
+		r.Resource().Attributes().PutStr("resourceName", "resource"+string(resource.id))
+		for _, scope := range resource.scopes {
+			s := r.ScopeMetrics().AppendEmpty()
+			s.Scope().SetName("scope" + string(scope.id))
+			for _, metric := range scope.metrics {
+				m := s.Metrics().AppendEmpty()
+				m.SetName("metric" + string(metric.id))
+				dps := m.SetEmptyGauge().DataPoints()
+				for i := 0; i < len(metric.dataPoints); i++ {
+					dp := dps.AppendEmpty()
+					dp.Attributes().PutStr("dpName", "dp"+string(metric.dataPoints[i]))
+				}
+			}
+		}
+	}
+	return md
+}