Define new component type "connector" (open-telemetry#6577)

This establishes the new component type without including anything
specific about the design of connectors.

.chloggen/connector-component.yaml

@@ -0,0 +1,16 @@
+# 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. otlpreceiver)
+component: component
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Define new component type 'connectors'
+
+# One or more tracking issues or pull requests related to the change
+issues: [6577]
+
+# (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:

component/component.go

@@ -104,6 +104,7 @@ const (
 	KindProcessor
 	KindExporter
 	KindExtension
+	KindConnector
 )
 
 // StabilityLevel represents the stability level of the component created by the factory.

config/connector.go

@@ -0,0 +1,46 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//       http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config // import "go.opentelemetry.io/collector/config"
+
+import (
+	"go.opentelemetry.io/collector/component"
+)
+
+// ConnectorSettings defines common settings for a component.Connector configuration.
+// Specific connectors can embed this struct and extend it with more fields if needed.
+//
+// It is highly recommended to "override" the Validate() function.
+//
+// When embedded in the exporter config, it must be with `mapstructure:",squash"` tag.
+type ConnectorSettings struct {
+	settings
+}
+
+// NewConnectorSettings return a new ConnectorSettings with the given ComponentID.
+func NewConnectorSettings(id component.ID) ConnectorSettings {
+	return ConnectorSettings{settings: newSettings(id)}
+}
+
+var _ component.Config = (*ConnectorSettings)(nil)
+
+// ID returns the connector ComponentID.
+func (cs *ConnectorSettings) ID() component.ID {
+	return cs.id
+}
+
+// SetIDName sets the connector name.
+func (cs *ConnectorSettings) SetIDName(idName string) {
+	cs.id = component.NewIDWithName(cs.id.Type(), idName)
+}

connector/connector.go

@@ -0,0 +1,37 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//       http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package connector // import "go.opentelemetry.io/collector/connector"
+
+import (
+	"go.opentelemetry.io/collector/component"
+)
+
+// Connector sends telemetry data from one pipeline to another. A connector
+// is both an exporter and receiver, working together to connect pipelines.
+// The purpose is to allow for differentiated processing of telemetry data.
+//
+// Connectors can be used to replicate or route data, merge data streams,
+// derive signals from other signals, etc.
+type Connector interface {
+	component.Component
+}
+
+// CreateSettings configures Connector creators.
+type CreateSettings struct {
+	TelemetrySettings component.TelemetrySettings
+
+	// BuildInfo can be used by components for informational purposes
+	BuildInfo component.BuildInfo
+}