[OpAMP] parse comma separated tags list from non-identifying attributes

internal/pkg/api/handleOpAMP.go

@@ -38,6 +38,7 @@ const (
 	kOpAMPMod          = "opAMP"
 	serverCapabilities = uint64(protobufs.ServerCapabilities_ServerCapabilities_AcceptsStatus |
 		protobufs.ServerCapabilities_ServerCapabilities_AcceptsEffectiveConfig)
+	tagsKey = "tags"
 )
 
 type OpAMPT struct {
@@ -288,6 +289,7 @@ func (oa *OpAMPT) enrollAgent(zlog zerolog.Logger, agentID string, aToS *protobu
 	meta := localMetadata{}
 	meta.Elastic.Agent.ID = agentID
 	agentType := ""
+	var tags []string
 	var identifyingAttributes, nonIdentifyingAttributes json.RawMessage
 	if aToS.AgentDescription != nil {
 		// Extract agent version
@@ -302,7 +304,7 @@ func (oa *OpAMPT) enrollAgent(zlog zerolog.Logger, agentID string, aToS *protobu
 		}
 		zlog.Debug().Str("opamp.agent.version", meta.Elastic.Agent.Version).Msg("extracted agent version")
 
-		// Extract hostname
+		// Extract hostname and tags
 		for _, nia := range aToS.AgentDescription.NonIdentifyingAttributes {
 			switch attribute.Key(nia.Key) {
 			case semconv.HostNameKey:
@@ -312,6 +314,12 @@ func (oa *OpAMPT) enrollAgent(zlog zerolog.Logger, agentID string, aToS *protobu
 			case semconv.OSTypeKey:
 				osType := nia.GetValue().GetStringValue()
 				meta.Os.Platform = osType
+			case tagsKey:
+				for _, t := range strings.Split(nia.GetValue().GetStringValue(), ",") {
+					if t = strings.TrimSpace(t); t != "" {
+						tags = append(tags, t)
+					}
+				}
 			}
 		}
 		zlog.Debug().Str("hostname", meta.Host.Hostname).Msg("extracted hostname")
@@ -321,7 +329,13 @@ func (oa *OpAMPT) enrollAgent(zlog zerolog.Logger, agentID string, aToS *protobu
 			return nil, fmt.Errorf("failed to marshal identifying attributes: %w", err)
 		}
 
-		nonIdentifyingAttributes, err = ProtobufKVToRawMessage(zlog, aToS.AgentDescription.NonIdentifyingAttributes)
+		filteredNIA := make([]*protobufs.KeyValue, 0, len(aToS.AgentDescription.NonIdentifyingAttributes))
+		for _, nia := range aToS.AgentDescription.NonIdentifyingAttributes {
+			if nia.Key != tagsKey {
+				filteredNIA = append(filteredNIA, nia)
+			}
+		}
+		nonIdentifyingAttributes, err = ProtobufKVToRawMessage(zlog, filteredNIA)
 		if err != nil {
 			return nil, fmt.Errorf("failed to marshal non-identifying attributes: %w", err)
 		}
@@ -349,7 +363,7 @@ func (oa *OpAMPT) enrollAgent(zlog zerolog.Logger, agentID string, aToS *protobu
 		IdentifyingAttributes:    identifyingAttributes,
 		NonIdentifyingAttributes: nonIdentifyingAttributes,
 		Type:                     "OPAMP",
-		Tags:                     []string{agentType},
+		Tags:                     dedupeSlice(append([]string{agentType}, tags...)),
 	}
 
 	data, err = json.Marshal(agent)
@@ -558,6 +572,19 @@ func isActiveStatus(status string) bool {
 		status == string(CheckinRequestStatusDegraded)
 }
 
+// dedupeSlice returns a copy of s with duplicate entries removed, preserving order.
+func dedupeSlice(s []string) []string {
+	seen := make(map[string]struct{}, len(s))
+	result := make([]string, 0, len(s))
+	for _, v := range s {
+		if _, ok := seen[v]; !ok {
+			seen[v] = struct{}{}
+			result = append(result, v)
+		}
+	}
+	return result
+}
+
 // decodeCapabilities converts capability bitmask to human-readable strings
 func decodeCapabilities(caps uint64) []string {
 	var result []string

internal/pkg/api/handleOpAMP_test.go

@@ -220,6 +220,107 @@ func TestEnrollAgentWithAgentToServerMessage(t *testing.T) {
 	bulker.AssertExpectations(t)
 }
 
+func TestEnrollAgentTags(t *testing.T) {
+	cases := []struct {
+		name         string
+		tagsValue    string
+		wantTags     []string
+		otherNIAKeys []string
+	}{
+		{
+			name:         "no tags attribute",
+			tagsValue:    "",
+			wantTags:     []string{"otel-collector"},
+			otherNIAKeys: []string{string(semconv.HostNameKey)},
+		},
+		{
+			name:         "single tag",
+			tagsValue:    "dev",
+			wantTags:     []string{"otel-collector", "dev"},
+			otherNIAKeys: []string{string(semconv.HostNameKey)},
+		},
+		{
+			name:         "multiple tags",
+			tagsValue:    "dev,west,us-west-1a",
+			wantTags:     []string{"otel-collector", "dev", "west", "us-west-1a"},
+			otherNIAKeys: []string{string(semconv.HostNameKey)},
+		},
+		{
+			name:         "tags with spaces",
+			tagsValue:    " dev , west , us-west-1a ",
+			wantTags:     []string{"otel-collector", "dev", "west", "us-west-1a"},
+			otherNIAKeys: []string{string(semconv.HostNameKey)},
+		},
+		{
+			name:         "duplicate of agent type is removed",
+			tagsValue:    "otel-collector,dev",
+			wantTags:     []string{"otel-collector", "dev"},
+			otherNIAKeys: []string{string(semconv.HostNameKey)},
+		},
+		{
+			name:         "duplicate tags within list are removed",
+			tagsValue:    "dev,west,dev",
+			wantTags:     []string{"otel-collector", "dev", "west"},
+			otherNIAKeys: []string{string(semconv.HostNameKey)},
+		},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			bulker := ftesting.NewMockBulk()
+			enrollKey := model.EnrollmentAPIKey{ //nolint:gosec // test data, not real credentials
+				APIKeyID: "enroll-key-id",
+				PolicyID: "policy-123",
+				Active:   true,
+			}
+			enrollKeyBytes, err := json.Marshal(enrollKey) //nolint:gosec // test data, not real credentials
+			require.NoError(t, err)
+			bulker.On("Search", mock.Anything, dl.FleetEnrollmentAPIKeys, mock.Anything, mock.Anything).
+				Return(&es.ResultT{HitsT: es.HitsT{Hits: []es.HitT{{Source: enrollKeyBytes}}}}, nil)
+			bulker.On("Create", mock.Anything, dl.FleetAgents, "agent-123", mock.Anything, mock.Anything).
+				Return("doc-id", nil)
+
+			nia := []*protobufs.KeyValue{
+				{
+					Key:   string(semconv.HostNameKey),
+					Value: &protobufs.AnyValue{Value: &protobufs.AnyValue_StringValue{StringValue: "host-1"}},
+				},
+			}
+			if tc.tagsValue != "" {
+				nia = append(nia, &protobufs.KeyValue{
+					Key:   "tags",
+					Value: &protobufs.AnyValue{Value: &protobufs.AnyValue_StringValue{StringValue: tc.tagsValue}},
+				})
+			}
+
+			msg := &protobufs.AgentToServer{
+				AgentDescription: &protobufs.AgentDescription{
+					IdentifyingAttributes: []*protobufs.KeyValue{
+						{
+							Key:   string(semconv.ServiceNameKey),
+							Value: &protobufs.AnyValue{Value: &protobufs.AnyValue_StringValue{StringValue: "otel-collector"}},
+						},
+					},
+					NonIdentifyingAttributes: nia,
+				},
+			}
+
+			oa := &OpAMPT{bulk: bulker}
+			zlog := zerolog.New(io.Discard)
+			agent, err := oa.enrollAgent(zlog, "agent-123", msg, &apikey.APIKey{ID: "enroll-key-id"})
+			require.NoError(t, err)
+			require.Equal(t, tc.wantTags, agent.Tags)
+
+			// tags must not appear in stored NonIdentifyingAttributes
+			var niMap map[string]interface{}
+			require.NoError(t, json.Unmarshal(agent.NonIdentifyingAttributes, &niMap))
+			require.NotContains(t, niMap, "tags")
+			for _, k := range tc.otherNIAKeys {
+				require.Contains(t, niMap, k, "expected NIA key %q to be present", k)
+			}
+		})
+	}
+}
+
 func TestUpdateAgentWithAgentToServerMessage(t *testing.T) {
 	checker := &mockCheckin{}
 	oa := &OpAMPT{bc: checker}