[extension/opamp] Add config options to specify extra non-identifying…

… attributes (#32153)

**Description:** <Describe what has changed.>
* Adds a new `agent_description.non_identifying_attributes` config
option to allow setting user-defined non-identifying attributes

**Link to tracking Issue:** Closes #32107

**Testing:**
Added unit tests
Manually tested against an OpAMP server

**Documentation:**
Added new parameter to extension docs

.chloggen/feat_opamp-extension-user-defined-attributes.yaml

@@ -0,0 +1,13 @@
+# 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: Added a new `agent_description.non_identifying_attributes` config option to allow setting user-defined non-identifying attributes
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [32107]

cmd/otelcontribcol/go.mod

@@ -694,7 +694,7 @@ require (
 	go.uber.org/multierr v1.11.0 // indirect
 	go.uber.org/zap v1.27.0 // indirect
 	golang.org/x/crypto v0.22.0 // indirect
-	golang.org/x/exp v0.0.0-20240205201215-2c58cdc269a3 // indirect
+	golang.org/x/exp v0.0.0-20240325151524-a685a6edb6d8 // indirect
 	golang.org/x/mod v0.16.0 // indirect
 	golang.org/x/net v0.24.0 // indirect
 	golang.org/x/oauth2 v0.19.0 // indirect

extension/opampextension/README.md

@@ -30,6 +30,8 @@ The following settings are optional:
   instance UID remains constant across process restarts.
 - `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`.
+- `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.
 
 ### Example
 

extension/opampextension/config.go

@@ -26,6 +26,15 @@ type Config struct {
 
 	// Capabilities contains options to enable a particular OpAMP capability
 	Capabilities Capabilities `mapstructure:"capabilities"`
+
+	// Agent descriptions contains options to modify the AgentDescription message
+	AgentDescription AgentDescription `mapstructure:"agent_description"`
+}
+
+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"`
 }
 
 type Capabilities struct {

extension/opampextension/go.mod

@@ -18,6 +18,7 @@ require (
 	go.opentelemetry.io/otel/trace v1.25.0
 	go.uber.org/goleak v1.3.0
 	go.uber.org/zap v1.27.0
+	golang.org/x/exp v0.0.0-20240325151524-a685a6edb6d8
 	gopkg.in/yaml.v3 v3.0.1
 )
 

extension/opampextension/opamp_agent.go

@@ -8,6 +8,7 @@ import (
 	"net/http"
 	"os"
 	"runtime"
+	"sort"
 	"strings"
 	"sync"
 
@@ -21,6 +22,7 @@ import (
 	"go.opentelemetry.io/collector/pdata/pcommon"
 	semconv "go.opentelemetry.io/collector/semconv/v1.18.0"
 	"go.uber.org/zap"
+	"golang.org/x/exp/maps"
 	"gopkg.in/yaml.v3"
 )
 
@@ -194,10 +196,25 @@ func (o *opampAgent) createAgentDescription() error {
 		stringKeyValue(semconv.AttributeServiceVersion, o.agentVersion),
 	}
 
-	nonIdent := []*protobufs.KeyValue{
-		stringKeyValue(semconv.AttributeOSType, runtime.GOOS),
-		stringKeyValue(semconv.AttributeHostArch, runtime.GOARCH),
-		stringKeyValue(semconv.AttributeHostName, hostname),
+	// Initially construct using a map to properly deduplicate any keys that
+	// are both automatically determined and defined in the config
+	nonIdentifyingAttributeMap := map[string]string{}
+	nonIdentifyingAttributeMap[semconv.AttributeOSType] = runtime.GOOS
+	nonIdentifyingAttributeMap[semconv.AttributeHostArch] = runtime.GOARCH
+	nonIdentifyingAttributeMap[semconv.AttributeHostName] = hostname
+
+	for k, v := range o.cfg.AgentDescription.NonIdentifyingAttributes {
+		nonIdentifyingAttributeMap[k] = v
+	}
+
+	// Sort the non identifying attributes to give them a stable order for tests
+	keys := maps.Keys(nonIdentifyingAttributeMap)
+	sort.Strings(keys)
+
+	nonIdent := make([]*protobufs.KeyValue, 0, len(nonIdentifyingAttributeMap))
+	for _, k := range keys {
+		v := nonIdentifyingAttributeMap[k]
+		nonIdent = append(nonIdent, stringKeyValue(k, v))
 	}
 
 	o.agentDescription = &protobufs.AgentDescription{

extension/opampextension/opamp_agent_test.go

@@ -7,10 +7,13 @@ import (
 	"context"
 	"os"
 	"path/filepath"
+	"runtime"
 	"testing"
 
 	"github.com/oklog/ulid/v2"
+	"github.com/open-telemetry/opamp-go/protobufs"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/component/componenttest"
 	"go.opentelemetry.io/collector/confmap/confmaptest"
@@ -47,15 +50,101 @@ func TestNewOpampAgentAttributes(t *testing.T) {
 }
 
 func TestCreateAgentDescription(t *testing.T) {
-	cfg := createDefaultConfig()
-	set := extensiontest.NewNopCreateSettings()
-	o, err := newOpampAgent(cfg.(*Config), set.Logger, set.BuildInfo, set.Resource)
-	assert.NoError(t, err)
-
-	assert.Nil(t, o.agentDescription)
-	err = o.createAgentDescription()
-	assert.NoError(t, err)
-	assert.NotNil(t, o.agentDescription)
+	hostname, err := os.Hostname()
+	require.NoError(t, err)
+
+	serviceName := "otelcol-distrot"
+	serviceVersion := "distro.0"
+	serviceInstanceUUID := "f8999bc1-4c9b-4619-9bae-7f009d2411ec"
+	serviceInstanceULID := "7RK6DW2K4V8RCSQBKZ02EJ84FC"
+
+	testCases := []struct {
+		name string
+		cfg  func(*Config)
+
+		expected *protobufs.AgentDescription
+	}{
+		{
+			name: "No extra attributes",
+			cfg:  func(_ *Config) {},
+			expected: &protobufs.AgentDescription{
+				IdentifyingAttributes: []*protobufs.KeyValue{
+					stringKeyValue(semconv.AttributeServiceInstanceID, serviceInstanceULID),
+					stringKeyValue(semconv.AttributeServiceName, serviceName),
+					stringKeyValue(semconv.AttributeServiceVersion, serviceVersion),
+				},
+				NonIdentifyingAttributes: []*protobufs.KeyValue{
+					stringKeyValue(semconv.AttributeHostArch, runtime.GOARCH),
+					stringKeyValue(semconv.AttributeHostName, hostname),
+					stringKeyValue(semconv.AttributeOSType, runtime.GOOS),
+				},
+			},
+		},
+		{
+			name: "Extra attributes specified",
+			cfg: func(c *Config) {
+				c.AgentDescription.NonIdentifyingAttributes = map[string]string{
+					"env":                       "prod",
+					semconv.AttributeK8SPodName: "my-very-cool-pod",
+				}
+			},
+			expected: &protobufs.AgentDescription{
+				IdentifyingAttributes: []*protobufs.KeyValue{
+					stringKeyValue(semconv.AttributeServiceInstanceID, serviceInstanceULID),
+					stringKeyValue(semconv.AttributeServiceName, serviceName),
+					stringKeyValue(semconv.AttributeServiceVersion, serviceVersion),
+				},
+				NonIdentifyingAttributes: []*protobufs.KeyValue{
+					stringKeyValue("env", "prod"),
+					stringKeyValue(semconv.AttributeHostArch, runtime.GOARCH),
+					stringKeyValue(semconv.AttributeHostName, hostname),
+					stringKeyValue(semconv.AttributeK8SPodName, "my-very-cool-pod"),
+					stringKeyValue(semconv.AttributeOSType, runtime.GOOS),
+				},
+			},
+		},
+		{
+			name: "Extra attributes override",
+			cfg: func(c *Config) {
+				c.AgentDescription.NonIdentifyingAttributes = map[string]string{
+					semconv.AttributeHostName: "override-host",
+				}
+			},
+			expected: &protobufs.AgentDescription{
+				IdentifyingAttributes: []*protobufs.KeyValue{
+					stringKeyValue(semconv.AttributeServiceInstanceID, serviceInstanceULID),
+					stringKeyValue(semconv.AttributeServiceName, serviceName),
+					stringKeyValue(semconv.AttributeServiceVersion, serviceVersion),
+				},
+				NonIdentifyingAttributes: []*protobufs.KeyValue{
+					stringKeyValue(semconv.AttributeHostArch, runtime.GOARCH),
+					stringKeyValue(semconv.AttributeHostName, "override-host"),
+					stringKeyValue(semconv.AttributeOSType, runtime.GOOS),
+				},
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+
+			cfg := createDefaultConfig().(*Config)
+			tc.cfg(cfg)
+
+			set := extensiontest.NewNopCreateSettings()
+			set.Resource.Attributes().PutStr(semconv.AttributeServiceName, serviceName)
+			set.Resource.Attributes().PutStr(semconv.AttributeServiceVersion, serviceVersion)
+			set.Resource.Attributes().PutStr(semconv.AttributeServiceInstanceID, serviceInstanceUUID)
+
+			o, err := newOpampAgent(cfg, set.Logger, set.BuildInfo, set.Resource)
+			require.NoError(t, err)
+			assert.Nil(t, o.agentDescription)
+
+			err = o.createAgentDescription()
+			assert.NoError(t, err)
+			require.Equal(t, tc.expected, o.agentDescription)
+		})
+	}
 }
 
 func TestUpdateAgentIdentity(t *testing.T) {