[extension/opamp] Report Available Components via OpAMP extension

.chloggen/report-available-components-opamp-extension.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: opampextension
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Support retrieval of available components via the OpAMP extension.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [37246]
+
+# (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: []

extension/opampextension/README.md

@@ -45,6 +45,7 @@ The following settings are optional for both transports:
 - `capabilities`: Keys with boolean true/false values that enable a particular OpAMP capability.
   - `reports_effective_config`: Whether to enable the OpAMP ReportsEffectiveConfig capability. Default is `true`.
   - `reports_health`: Whether to enable the OpAMP ReportsHealth capability. Default is `true`.
+  - `reports_available_components`: Whether to enable the OpAMP ReportsAvailableComponents capability. Default is `true`.
 - `agent_description`: Setting that modifies the agent description reported to the OpAMP server.
   - `non_identifying_attributes`: A map of key value pairs that will be added to the [non-identifying attributes](https://github.com/open-telemetry/opamp-spec/blob/main/specification.md#agentdescriptionnon_identifying_attributes) reported to the OpAMP server. If an attribute collides with the default non-identifying attributes that are automatically added, the ones specified here take precedence.
 - `ppid`: An optional process ID to monitor. When this process is no longer running, the extension will emit a fatal error, causing the collector to exit. This is meant to be set by the Supervisor or some other parent process, and should not be configured manually.

extension/opampextension/config.go

@@ -56,6 +56,8 @@ type Capabilities struct {
 	ReportsEffectiveConfig bool `mapstructure:"reports_effective_config"`
 	// ReportsHealth enables the OpAMP ReportsHealth Capability. (default: true)
 	ReportsHealth bool `mapstructure:"reports_health"`
+	// ReportsAvailableComponents enables the OpAMP ReportsAvailableComponents Capability (default: true)
+	ReportsAvailableComponents bool `mapstructure:"reports_available_components"`
 }
 
 func (caps Capabilities) toAgentCapabilities() protobufs.AgentCapabilities {
@@ -69,6 +71,10 @@ func (caps Capabilities) toAgentCapabilities() protobufs.AgentCapabilities {
 		agentCapabilities |= protobufs.AgentCapabilities_AgentCapabilities_ReportsHealth
 	}
 
+	if caps.ReportsAvailableComponents {
+		agentCapabilities |= protobufs.AgentCapabilities_AgentCapabilities_ReportsAvailableComponents
+	}
+
 	return agentCapabilities
 }
 

extension/opampextension/config_test.go

@@ -39,8 +39,9 @@ func TestUnmarshalConfig(t *testing.T) {
 			},
 			InstanceUID: "01BX5ZZKBKACTAV9WEVGEMMVRZ",
 			Capabilities: Capabilities{
-				ReportsEffectiveConfig: true,
-				ReportsHealth:          true,
+				ReportsEffectiveConfig:     true,
+				ReportsHealth:              true,
+				ReportsAvailableComponents: true,
 			},
 			PPIDPollInterval: 5 * time.Second,
 		}, cfg)
@@ -64,8 +65,9 @@ func TestUnmarshalHttpConfig(t *testing.T) {
 			},
 			InstanceUID: "01BX5ZZKBKACTAV9WEVGEMMVRZ",
 			Capabilities: Capabilities{
-				ReportsEffectiveConfig: true,
-				ReportsHealth:          true,
+				ReportsEffectiveConfig:     true,
+				ReportsHealth:              true,
+				ReportsAvailableComponents: true,
 			},
 			PPIDPollInterval: 5 * time.Second,
 		}, cfg)
@@ -292,8 +294,9 @@ func TestConfig_Validate(t *testing.T) {
 
 func TestCapabilities_toAgentCapabilities(t *testing.T) {
 	type fields struct {
-		ReportsEffectiveConfig bool
-		ReportsHealth          bool
+		ReportsEffectiveConfig     bool
+		ReportsHealth              bool
+		ReportsAvailableComponents bool
 	}
 	tests := []struct {
 		name   string
@@ -303,25 +306,28 @@ func TestCapabilities_toAgentCapabilities(t *testing.T) {
 		{
 			name: "default capabilities",
 			fields: fields{
-				ReportsEffectiveConfig: false,
-				ReportsHealth:          false,
+				ReportsEffectiveConfig:     false,
+				ReportsHealth:              false,
+				ReportsAvailableComponents: false,
 			},
 			want: protobufs.AgentCapabilities_AgentCapabilities_ReportsStatus,
 		},
 		{
 			name: "all supported capabilities enabled",
 			fields: fields{
-				ReportsEffectiveConfig: true,
-				ReportsHealth:          true,
+				ReportsEffectiveConfig:     true,
+				ReportsHealth:              true,
+				ReportsAvailableComponents: true,
 			},
-			want: protobufs.AgentCapabilities_AgentCapabilities_ReportsStatus | protobufs.AgentCapabilities_AgentCapabilities_ReportsEffectiveConfig | protobufs.AgentCapabilities_AgentCapabilities_ReportsHealth,
+			want: protobufs.AgentCapabilities_AgentCapabilities_ReportsStatus | protobufs.AgentCapabilities_AgentCapabilities_ReportsEffectiveConfig | protobufs.AgentCapabilities_AgentCapabilities_ReportsHealth | protobufs.AgentCapabilities_AgentCapabilities_ReportsAvailableComponents,
 		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			caps := Capabilities{
-				ReportsEffectiveConfig: tt.fields.ReportsEffectiveConfig,
-				ReportsHealth:          tt.fields.ReportsHealth,
+				ReportsEffectiveConfig:     tt.fields.ReportsEffectiveConfig,
+				ReportsHealth:              tt.fields.ReportsHealth,
+				ReportsAvailableComponents: tt.fields.ReportsEffectiveConfig,
 			}
 			assert.Equalf(t, tt.want, caps.toAgentCapabilities(), "toAgentCapabilities()")
 		})

extension/opampextension/factory.go

@@ -26,8 +26,9 @@ func createDefaultConfig() component.Config {
 	return &Config{
 		Server: &OpAMPServer{},
 		Capabilities: Capabilities{
-			ReportsEffectiveConfig: true,
-			ReportsHealth:          true,
+			ReportsEffectiveConfig:     true,
+			ReportsHealth:              true,
+			ReportsAvailableComponents: true,
 		},
 		PPIDPollInterval: 5 * time.Second,
 	}

extension/opampextension/go.mod

@@ -2,10 +2,12 @@ module github.com/open-telemetry/opentelemetry-collector-contrib/extension/opamp
 
 go 1.22.0
 
+replace github.com/open-telemetry/opamp-go => /Users/ian/git/opamp-go
+
 require (
 	github.com/google/uuid v1.6.0
 	github.com/oklog/ulid/v2 v2.1.0
-	github.com/open-telemetry/opamp-go v0.18.0
+	github.com/open-telemetry/opamp-go v0.18.1-0.20250109233938-e6fac32dddf5
 	github.com/open-telemetry/opentelemetry-collector-contrib/extension/opampcustommessages v0.117.0
 	github.com/open-telemetry/opentelemetry-collector-contrib/pkg/status v0.117.0
 	github.com/shirou/gopsutil/v4 v4.24.12

extension/opampextension/opamp_agent.go

@@ -5,6 +5,7 @@ package opampextension // import "github.com/open-telemetry/opentelemetry-collec
 
 import (
 	"context"
+	"crypto/sha256"
 	"errors"
 	"fmt"
 	"net/http"
@@ -66,7 +67,8 @@ type opampAgent struct {
 
 	capabilities Capabilities
 
-	agentDescription *protobufs.AgentDescription
+	agentDescription    *protobufs.AgentDescription
+	availableComponents *protobufs.AvailableComponents
 
 	opampClient client.OpAMPClient
 
@@ -133,7 +135,8 @@ func (o *opampAgent) Start(ctx context.Context, host component.Host) error {
 			},
 			OnMessage: o.onMessage,
 		},
-		Capabilities: o.capabilities.toAgentCapabilities(),
+		Capabilities:        o.capabilities.toAgentCapabilities(),
+		AvailableComponents: o.availableComponents,
 	}
 
 	if err := o.createAgentDescription(); err != nil {
@@ -303,6 +306,8 @@ func newOpampAgent(cfg *Config, set extension.Settings) (*opampAgent, error) {
 		agent.initHealthReporting()
 	}
 
+	agent.initAvailableComponents(set.ModuleInfo)
+
 	return agent, nil
 }
 
@@ -472,6 +477,83 @@ func (o *opampAgent) initHealthReporting() {
 	go o.componentHealthEventLoop()
 }
 
+func (o *opampAgent) initAvailableComponents(set extension.ModuleInfo) {
+	if !o.capabilities.ReportsAvailableComponents {
+		return
+	}
+
+	o.availableComponents = &protobufs.AvailableComponents{
+		Hash: generateAvailableComponentsHash(set),
+		Components: map[string]*protobufs.ComponentDetails{
+			"receivers": {
+				SubComponentMap: createComponentTypeAvailableComponentDetails(set.Receiver),
+			},
+			"processors": {
+				SubComponentMap: createComponentTypeAvailableComponentDetails(set.Processor),
+			},
+			"exporters": {
+				SubComponentMap: createComponentTypeAvailableComponentDetails(set.Exporter),
+			},
+			"extensions": {
+				SubComponentMap: createComponentTypeAvailableComponentDetails(set.Extension),
+			},
+			"connectors": {
+				SubComponentMap: createComponentTypeAvailableComponentDetails(set.Connector),
+			},
+		},
+	}
+}
+
+func generateAvailableComponentsHash(set extension.ModuleInfo) []byte {
+	var builder strings.Builder
+
+	addComponentTypeComponentsToStringBuilder(&builder, set.Receiver, "receiver")
+	addComponentTypeComponentsToStringBuilder(&builder, set.Processor, "processor")
+	addComponentTypeComponentsToStringBuilder(&builder, set.Exporter, "exporter")
+	addComponentTypeComponentsToStringBuilder(&builder, set.Extension, "extension")
+	addComponentTypeComponentsToStringBuilder(&builder, set.Connector, "connector")
+
+	// Compute the SHA-256 hash of the serialized representation.
+	hash := sha256.Sum256([]byte(builder.String()))
+	return hash[:]
+}
+
+func addComponentTypeComponentsToStringBuilder(builder *strings.Builder, componentTypeComponents map[component.Type]string, componentType string) {
+	// Collect components and sort them to ensure deterministic ordering.
+	components := make([]component.Type, 0, len(componentTypeComponents))
+	for k := range componentTypeComponents {
+		components = append(components, k)
+	}
+	sort.Slice(components, func(i, j int) bool {
+		return components[i].String() < components[j].String()
+	})
+
+	// Append the component type and its sorted key-value pairs.
+	builder.WriteString(componentType + ":")
+	for _, k := range components {
+		builder.WriteString(k.String() + "=" + componentTypeComponents[k] + ";")
+	}
+}
+
+func createComponentTypeAvailableComponentDetails(componentTypeComponents map[component.Type]string) map[string]*protobufs.ComponentDetails {
+	availableComponentDetails := map[string]*protobufs.ComponentDetails{}
+	for componentType, r := range componentTypeComponents {
+		availableComponentDetails[componentType.String()] = &protobufs.ComponentDetails{
+			Metadata: []*protobufs.KeyValue{
+				{
+					Key: "code.namespace",
+					Value: &protobufs.AnyValue{
+						Value: &protobufs.AnyValue_StringValue{
+							StringValue: r,
+						},
+					},
+				},
+			},
+		}
+	}
+	return availableComponentDetails
+}
+
 func (o *opampAgent) componentHealthEventLoop() {
 	// Record events with component.StatusStarting, but queue other events until
 	// PipelineWatcher.Ready is called. This prevents aggregate statuses from