Allow opamp extension to include resource attributes automatically (open-telemetry#38994)

#### Description
Introduces a new config struct element `IncludeResourceAttributes` which
when enabled (default is false) copies the set resource attributes from
the agent into the non-identifying attributes in the agent description
message.


#### Link to tracking issue
Fixes open-telemetry#37487

#### Testing
Unit


#### Documentation
n/a

---------

Co-authored-by: Evan Bradley <[email protected]>

Author: 2 people

.chloggen/enable-resource-attr-copying.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: Introduces a new config field `include_resource_attributes` which allows the extension to copy the agent's resource attributes to the non-identifying attributes in the agent description.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [37487]
+
+# (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]

extension/opampextension/README.md

@@ -47,6 +47,7 @@ The following settings are optional for both transports:
   - `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.
+  - `include_resource_attributes`: Copy the Collector's resource attributes into the set of non-identifying attributes in the agent description.
   - `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.
 - `ppid_poll_interval`: The poll interval between check for whether `ppid` is still alive or not. Defaults to 5 seconds.

extension/opampextension/config.go

@@ -49,6 +49,9 @@ type AgentDescription struct {
 	// NonIdentifyingAttributes are a map of key-value pairs that may be specified to provide
 	// extra information about the agent to the OpAMP server.
 	NonIdentifyingAttributes map[string]string `mapstructure:"non_identifying_attributes"`
+	// IncludeResourceAttributes determines whether the agent should copy its resource attributes
+	// to the non identifying attributes. (default: false)
+	IncludeResourceAttributes bool `mapstructure:"include_resource_attributes"`
 }
 
 type Capabilities struct {

extension/opampextension/go.mod

@@ -111,7 +111,7 @@ require (
 	github.com/tklauser/go-sysconf v0.3.14 // indirect
 	github.com/tklauser/numcpus v0.8.0 // indirect
 	github.com/yusufpapurcu/wmi v1.2.4 // indirect
-	go.opentelemetry.io/collector/pdata v1.30.0 // indirect
+	go.opentelemetry.io/collector/pdata v1.30.0
 	go.opentelemetry.io/collector/pipeline v0.124.0 // indirect
 	go.opentelemetry.io/otel v1.35.0 // indirect
 	go.opentelemetry.io/otel/metric v1.35.0 // indirect

extension/opampextension/opamp_agent.go

@@ -26,6 +26,7 @@ import (
 	"go.opentelemetry.io/collector/confmap"
 	"go.opentelemetry.io/collector/extension"
 	"go.opentelemetry.io/collector/extension/extensioncapabilities"
+	"go.opentelemetry.io/collector/pdata/pcommon"
 	semconv "go.opentelemetry.io/collector/semconv/v1.27.0"
 	"go.opentelemetry.io/collector/service"
 	"go.uber.org/zap"
@@ -52,8 +53,9 @@ type opampAgent struct {
 	cfg    *Config
 	logger *zap.Logger
 
-	agentType    string
-	agentVersion string
+	agentType     string
+	agentVersion  string
+	resourceAttrs map[string]string
 
 	instanceID uuid.UUID
 
@@ -89,6 +91,14 @@ var (
 	_ extensioncapabilities.ConfigWatcher          = (*opampAgent)(nil)
 	_ extensioncapabilities.PipelineWatcher        = (*opampAgent)(nil)
 	_ componentstatus.Watcher                      = (*opampAgent)(nil)
+
+	// identifyingAttributes is the list of semantic convention keys that are used
+	// for the agent description's identifying attributes.
+	identifyingAttributes = map[string]struct{}{
+		semconv.AttributeServiceName:       {},
+		semconv.AttributeServiceVersion:    {},
+		semconv.AttributeServiceInstanceID: {},
+	}
 )
 
 // moduleInfo exposes the internal collector moduleInfo interface
@@ -303,6 +313,11 @@ func newOpampAgent(cfg *Config, set extension.Settings) (*opampAgent, error) {
 			}
 		}
 	}
+	resourceAttrs := make(map[string]string, set.Resource.Attributes().Len())
+	set.Resource.Attributes().Range(func(k string, v pcommon.Value) bool {
+		resourceAttrs[k] = v.Str()
+		return true
+	})
 
 	opampClient := cfg.Server.GetClient(set.Logger)
 	agent := &opampAgent{
@@ -313,6 +328,7 @@ func newOpampAgent(cfg *Config, set extension.Settings) (*opampAgent, error) {
 		instanceID:               uid,
 		capabilities:             cfg.Capabilities,
 		opampClient:              opampClient,
+		resourceAttrs:            resourceAttrs,
 		statusSubscriptionWg:     &sync.WaitGroup{},
 		componentHealthWg:        &sync.WaitGroup{},
 		readyCh:                  make(chan struct{}),
@@ -375,6 +391,15 @@ func (o *opampAgent) createAgentDescription() error {
 	for k, v := range o.cfg.AgentDescription.NonIdentifyingAttributes {
 		nonIdentifyingAttributeMap[k] = v
 	}
+	if o.cfg.AgentDescription.IncludeResourceAttributes {
+		for k, v := range o.resourceAttrs {
+			// skip the attributes that are being used in the identifying attributes.
+			if _, ok := identifyingAttributes[k]; ok {
+				continue
+			}
+			nonIdentifyingAttributeMap[k] = v
+		}
+	}
 
 	// Sort the non identifying attributes to give them a stable order for tests
 	keys := maps.Keys(nonIdentifyingAttributeMap)

extension/opampextension/opamp_agent_test.go

@@ -71,6 +71,8 @@ func TestCreateAgentDescription(t *testing.T) {
 	serviceName := "otelcol-distrot"
 	serviceVersion := "distro.0"
 	serviceInstanceUUID := "f8999bc1-4c9b-4619-9bae-7f009d2411ec"
+	extraResourceAttrKey := "hello"
+	extraResourceAttrValue := "world"
 
 	testCases := []struct {
 		name string
@@ -140,6 +142,26 @@ func TestCreateAgentDescription(t *testing.T) {
 				},
 			},
 		},
+		{
+			name: "Set IncludeResourceAttributes",
+			cfg: func(c *Config) {
+				c.AgentDescription.IncludeResourceAttributes = true
+			},
+			expected: &protobufs.AgentDescription{
+				IdentifyingAttributes: []*protobufs.KeyValue{
+					stringKeyValue(semconv.AttributeServiceInstanceID, serviceInstanceUUID),
+					stringKeyValue(semconv.AttributeServiceName, serviceName),
+					stringKeyValue(semconv.AttributeServiceVersion, serviceVersion),
+				},
+				NonIdentifyingAttributes: []*protobufs.KeyValue{
+					stringKeyValue(extraResourceAttrKey, extraResourceAttrValue),
+					stringKeyValue(semconv.AttributeHostArch, runtime.GOARCH),
+					stringKeyValue(semconv.AttributeHostName, hostname),
+					stringKeyValue(semconv.AttributeOSDescription, description),
+					stringKeyValue(semconv.AttributeOSType, runtime.GOOS),
+				},
+			},
+		},
 	}
 
 	for _, tc := range testCases {
@@ -151,6 +173,7 @@ func TestCreateAgentDescription(t *testing.T) {
 			set.Resource.Attributes().PutStr(semconv.AttributeServiceName, serviceName)
 			set.Resource.Attributes().PutStr(semconv.AttributeServiceVersion, serviceVersion)
 			set.Resource.Attributes().PutStr(semconv.AttributeServiceInstanceID, serviceInstanceUUID)
+			set.Resource.Attributes().PutStr(extraResourceAttrKey, extraResourceAttrValue)
 
 			o, err := newOpampAgent(cfg, set)
 			require.NoError(t, err)