Fix drop processor for monitoring components

It fixes the drop processor for monitoring component logs, instead
of using the dataset that does not include any information about
whether the component is a monitoring component it now uses the
`component.id`.

changelog/fragments/1688401847-Fix-drop-processor-for-monitoring-components.yaml

@@ -0,0 +1,13 @@
+kind: bug-fix
+
+summary: Fix drop processor for monitoring components
+description: >-
+  It fixes the drop processor for monitoring component logs, instead
+  of using the dataset that does not include any information about
+  whether the component is a monitoring component it now uses the
+  `component.id`.
+component: elastic-agent
+
+pr: https://github.com/elastic/elastic-agent/pull/2982
+
+issue: https://github.com/elastic/elastic-agent/issues/2388

internal/pkg/agent/application/monitoring/v1_monitor.go

@@ -324,32 +324,21 @@ func (b *BeatsMonitor) injectLogsInput(cfg map[string]interface{}, components []
 					},
 				},
 			},
-			"processors": []interface{}{
+			"processors": []any{
 				// drop all events from monitoring components (do it early)
 				// without dropping these events the filestream gets stuck in an infinite loop
 				// if filestream hits an issue publishing the events it logs an error which then filestream monitor
-				// will read from the logs and try to also publish that new log message (thus the infinite loop)
+				// will read from the logs and try to also publish that new log message (thus the infinite loop).
+				// The only way to identify a monitoring component by looking
+				// at their ID. They all end in `-monitoring`, e.g:
+				// - "beat/metrics-monitoring"
+				// - "filestream-monitoring"
+				// - "http/metrics-monitoring"
 				map[string]interface{}{
 					"drop_event": map[string]interface{}{
 						"when": map[string]interface{}{
-							"or": []interface{}{
-								map[string]interface{}{
-									"equals": map[string]interface{}{
-										"component.dataset": fmt.Sprintf("elastic_agent.filestream_%s", monitoringOutput),
-									},
-								},
-								// for consistency this monitor is also not shipped (fetch-able with diagnostics)
-								map[string]interface{}{
-									"equals": map[string]interface{}{
-										"component.dataset": fmt.Sprintf("elastic_agent.beats_metrics_%s", monitoringOutput),
-									},
-								},
-								// for consistency with this monitor is also not shipped (fetch-able with diagnostics)
-								map[string]interface{}{
-									"equals": map[string]interface{}{
-										"component.dataset": fmt.Sprintf("elastic_agent.http_metrics_%s", monitoringOutput),
-									},
-								},
+							"regexp": map[string]interface{}{
+								"component.id": ".*-monitoring$",
 							},
 						},
 					},
@@ -432,7 +421,8 @@ func (b *BeatsMonitor) injectLogsInput(cfg map[string]interface{}, components []
 					"add_formatted_index": map[string]interface{}{
 						"index": "%{[data_stream.type]}-%{[data_stream.dataset]}-%{[data_stream.namespace]}",
 					},
-				}},
+				},
+			},
 		},
 	}
 

pkg/testing/tools/elasticsearch.go

@@ -209,6 +209,41 @@ func GetLogsForDatastream(client elastictransport.Interface, index string) (Docu
 	return GetLogsForDatastreamWithContext(context.Background(), client, index)
 }
 
+// GetLogsForAgentID returns any logs associated with the agent ID
+func GetLogsForAgentID(client elastictransport.Interface, id string) (Documents, error) {
+	indexQuery := map[string]interface{}{
+		"query": map[string]interface{}{
+			"match": map[string]interface{}{
+				"data_stream.dataset": "elastic_agent.*",
+			},
+		},
+	}
+
+	var buf bytes.Buffer
+	err := json.NewEncoder(&buf).Encode(indexQuery)
+	if err != nil {
+		return Documents{}, fmt.Errorf("error creating ES query: %w", err)
+	}
+
+	es := esapi.New(client)
+	res, err := es.Search(
+		es.Search.WithIndex("*.ds-logs*"),
+		es.Search.WithExpandWildcards("all"),
+		es.Search.WithBody(&buf),
+		es.Search.WithTrackTotalHits(true),
+		es.Search.WithPretty(),
+		es.Search.WithContext(context.Background()),
+		es.Search.WithQuery(fmt.Sprintf(`elastic_agent.id:%s`, id)),
+		// magic number, we try to get all entries it helps debugging test failures
+		es.Search.WithSize(300),
+	)
+	if err != nil {
+		return Documents{}, fmt.Errorf("error performing ES search: %w", err)
+	}
+
+	return handleDocsResponse(res)
+}
+
 // GetLogsForDatastreamWithContext returns any logs associated with the datastream
 func GetLogsForDatastreamWithContext(ctx context.Context, client elastictransport.Interface, index string) (Documents, error) {
 	indexQuery := map[string]interface{}{

testing/integration/enroll_test.go

@@ -7,18 +7,20 @@
 package integration
 
 import (
+	"encoding/json"
 	"fmt"
+	"os"
+	"regexp"
 	"testing"
 	"time"
 
+	"github.com/stretchr/testify/require"
 	"github.com/stretchr/testify/suite"
 
 	"github.com/elastic/elastic-agent-libs/kibana"
 	atesting "github.com/elastic/elastic-agent/pkg/testing"
 	"github.com/elastic/elastic-agent/pkg/testing/define"
 	"github.com/elastic/elastic-agent/pkg/testing/tools"
-
-	"github.com/stretchr/testify/require"
 )
 
 func TestEnrollAndLog(t *testing.T) {
@@ -27,7 +29,7 @@ func TestEnrollAndLog(t *testing.T) {
 			{Type: define.Linux},
 		},
 		Stack: &define.Stack{},
-		Local: false,
+		Local: true,
 		Sudo:  true,
 	})
 	t.Logf("got namespace: %s", info.Namespace)
@@ -47,8 +49,84 @@ func (runner *EnrollRunner) SetupSuite() {
 	require.NoError(runner.T(), err)
 }
 
-func (runner *EnrollRunner) SetupTest() {
+func (runner *EnrollRunner) SetupTest() {}
+
+// TestDropMonitoringLogs ensures logs from the monitoring components are not
+// sent to the output
+func (runner *EnrollRunner) TestDropMonitoringLogs() {
+	t := runner.T()
+	t.Logf("In TestDropMonitoringLogs")
+
+	defineInfo := runner.requirementsInfo
+	kibClient := runner.requirementsInfo.KibanaClient
+
+	// Enroll agent in Fleet with a test policy
+	createPolicyReq := kibana.AgentPolicy{
+		Name:        fmt.Sprintf("test-monitoring-logs-%d", time.Now().Unix()),
+		Namespace:   "testdropmonitoringlogs",
+		Description: "test policy for drop processors",
+		MonitoringEnabled: []kibana.MonitoringEnabledOption{
+			kibana.MonitoringEnabledLogs,
+			kibana.MonitoringEnabledMetrics,
+		},
+		AgentFeatures: []map[string]interface{}{
+			{
+				"name":    t.Name(),
+				"enabled": true,
+			},
+		},
+	}
+
+	// As part of the cleanup process, we'll uninstall the agent
+	policy, err := tools.InstallAgentWithPolicy(t, runner.agentFixture, kibClient, createPolicyReq)
+	require.NoError(t, err, "could not install Elastic Agent with Policy")
+	t.Logf("created policy: %s", policy.ID)
+
+	t.Cleanup(func() {
+		require.NoError(t, tools.UnEnrollAgent(kibClient), "could not un-enroll Elastic-Agent")
+	})
+
+	t.Log("waiting 20s so the components can generate some logs and" +
+		"Filebeat can collect them")
+	time.Sleep(20 * time.Second)
+	t.Log("Done sleeping")
 
+	hostname, err := os.Hostname()
+	if err != nil {
+		t.Fatalf("could not get hostname to filter Agent: %s", err)
+	}
+
+	agentID, err := tools.GetAgentIDByHostname(defineInfo.KibanaClient, hostname)
+	t.Logf("Agent ID: %q", agentID)
+
+	// We cannot search for `component.id` because at the moment of writing
+	// this field is not mapped. There is an issue for that:
+	// https://github.com/elastic/integrations/issues/6545
+	docs, err := tools.GetLogsForAgentID(defineInfo.ESClient, agentID)
+	require.NoError(t, err, "could not get logs from Agent ID: %q, err: %s",
+		agentID, err)
+
+	monRegExp := regexp.MustCompile(".*-monitoring$")
+	for i, d := range docs.Hits.Hits {
+		// Lazy way to navigate a map[string]any: convert to JSON then
+		// decode into a struct.
+		jsonData, err := json.Marshal(d.Source)
+		if err != nil {
+			t.Fatalf("could not encode document source as JSON: %s", err)
+		}
+
+		doc := ESDocument{}
+		if err := json.Unmarshal(jsonData, &doc); err != nil {
+			t.Fatalf("could not unmarshal document source: %s", err)
+		}
+
+		if monRegExp.MatchString(doc.Component.ID) {
+			t.Errorf("[%d] Document on index %q with 'component.id': %q "+
+				"and 'elastic_agent.id': %q. 'elastic_agent.id' must not "+
+				"end in '-monitoring'\n",
+				i, d.Index, doc.Component.ID, doc.ElasticAgent.ID)
+		}
+	}
 }
 
 func (runner *EnrollRunner) TestEnroll() {
@@ -129,3 +207,21 @@ func (runner *EnrollRunner) TestEnroll() {
 	require.NotZero(runner.T(), len(docs.Hits.Hits))
 
 }
+
+type ESDocument struct {
+	ElasticAgent ElasticAgent `json:"elastic_agent"`
+	Component    Component    `json:"component"`
+	Host         Host         `json:"host"`
+}
+type ElasticAgent struct {
+	ID       string `json:"id"`
+	Version  string `json:"version"`
+	Snapshot bool   `json:"snapshot"`
+}
+type Component struct {
+	Binary string `json:"binary"`
+	ID     string `json:"id"`
+}
+type Host struct {
+	Hostname string `json:"hostname"`
+}