[chore][mdatagen] Support connector in MetricsBuilder generated code

.chloggen/fix_cmd_mdata-gen-metrics.yml

@@ -0,0 +1,25 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. otlpreceiver)
+component: mdatagen
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Fix mdatagen generated_metrics for connectors
+
+# One or more tracking issues or pull requests related to the change
+issues: [12402]
+
+# (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:
+
+# 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: [api]

cmd/mdatagen/README.md

@@ -17,7 +17,7 @@ Examples of this metadata about a component are:
 * its stability level
 * the distributions containing it
 * the types of pipelines it supports
-* metrics emitted in the case of a scraping receiver
+* metrics emitted in the case of a scraping receiver, a scrapper, or a connector
 
 The metadata generator defines a schema for specifying this information to ensure it is complete and well-formed.
 The metadata generator is then able to ingest the metadata, validate it against the schema and produce documentation in a standardized format.

cmd/mdatagen/go.mod

@@ -10,6 +10,8 @@ require (
 	go.opentelemetry.io/collector/component/componenttest v0.120.0
 	go.opentelemetry.io/collector/confmap v1.26.0
 	go.opentelemetry.io/collector/confmap/provider/fileprovider v1.26.0
+	go.opentelemetry.io/collector/connector v0.120.0
+	go.opentelemetry.io/collector/connector/connectortest v0.120.0
 	go.opentelemetry.io/collector/consumer v1.26.0
 	go.opentelemetry.io/collector/consumer/consumertest v0.120.0
 	go.opentelemetry.io/collector/filter v0.120.0
@@ -49,11 +51,14 @@ require (
 	github.com/spf13/pflag v1.0.6 // indirect
 	go.opentelemetry.io/auto/sdk v1.1.0 // indirect
 	go.opentelemetry.io/collector/component/componentstatus v0.120.0 // indirect
+	go.opentelemetry.io/collector/connector/xconnector v0.120.0 // indirect
 	go.opentelemetry.io/collector/consumer/consumererror v0.120.0 // indirect
 	go.opentelemetry.io/collector/consumer/xconsumer v0.120.0 // indirect
+	go.opentelemetry.io/collector/internal/fanoutconsumer v0.120.0 // indirect
 	go.opentelemetry.io/collector/pdata/pprofile v0.120.0 // indirect
 	go.opentelemetry.io/collector/pdata/testdata v0.120.0 // indirect
 	go.opentelemetry.io/collector/pipeline v0.120.0 // indirect
+	go.opentelemetry.io/collector/pipeline/xpipeline v0.120.0 // indirect
 	go.opentelemetry.io/collector/processor/xprocessor v0.120.0 // indirect
 	go.opentelemetry.io/collector/receiver/xreceiver v0.120.0 // indirect
 	go.opentelemetry.io/otel v1.34.0 // indirect
@@ -118,3 +123,7 @@ replace go.opentelemetry.io/collector/consumer/consumererror => ../../consumer/c
 replace go.opentelemetry.io/collector/scraper => ../../scraper
 
 replace go.opentelemetry.io/collector/scraper/scrapertest => ../../scraper/scrapertest
+
+replace go.opentelemetry.io/collector/connector => ../../connector
+
+replace go.opentelemetry.io/collector/connector/connectortest => ../../connector/connectortest

cmd/mdatagen/internal/sampleconnector/doc.go

@@ -0,0 +1,7 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+// Generate a test metrics builder from a sample metrics set covering all configuration options.
+//go:generate mdatagen metadata.yaml
+
+package sampleconnector // import "go.opentelemetry.io/collector/cmd/mdatagen/internal/sampleconnector"

cmd/mdatagen/internal/sampleconnector/documentation.md

@@ -0,0 +1,16 @@
+[comment]: <> (Code generated by mdatagen. DO NOT EDIT.)
+
+# sample
+
+## Resource Attributes
+
+| Name | Description | Values | Enabled |
+| ---- | ----------- | ------ | ------- |
+| map.resource.attr | Resource attribute with a map value. | Any Map | true |
+| optional.resource.attr | Explicitly disabled ResourceAttribute. | Any Str | false |
+| slice.resource.attr | Resource attribute with a slice value. | Any Slice | true |
+| string.enum.resource.attr | Resource attribute with a known set of string values. | Str: ``one``, ``two`` | true |
+| string.resource.attr | Resource attribute with any string value. | Any Str | true |
+| string.resource.attr_disable_warning | Resource attribute with any string value. | Any Str | true |
+| string.resource.attr_remove_warning | Resource attribute with any string value. | Any Str | false |
+| string.resource.attr_to_be_removed | Resource attribute with any string value. | Any Str | true |

cmd/mdatagen/internal/sampleconnector/factory.go

@@ -0,0 +1,41 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package sampleconnector // import "go.opentelemetry.io/collector/cmd/mdatagen/internal/sampleconnector"
+
+import (
+	"context"
+
+	"go.opentelemetry.io/collector/cmd/mdatagen/internal/sampleconnector/internal/metadata"
+	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/connector"
+	"go.opentelemetry.io/collector/consumer"
+	"go.opentelemetry.io/collector/pdata/pmetric"
+)
+
+// NewFactory returns a receiver.Factory for sample receiver.
+func NewFactory() connector.Factory {
+	return connector.NewFactory(
+		metadata.Type,
+		func() component.Config { return &struct{}{} },
+		connector.WithMetricsToMetrics(createMetricsToMetricsConnector, metadata.MetricsStability))
+}
+
+func createMetricsToMetricsConnector(context.Context, connector.Settings, component.Config, consumer.Metrics) (connector.Metrics, error) {
+	return nopInstance, nil
+}
+
+var nopInstance = &nopConnector{}
+
+type nopConnector struct {
+	component.StartFunc
+	component.ShutdownFunc
+}
+
+func (n nopConnector) Capabilities() consumer.Capabilities {
+	return consumer.Capabilities{MutatesData: false}
+}
+
+func (n nopConnector) ConsumeMetrics(context.Context, pmetric.Metrics) error {
+	return nil
+}