[8.15](backport #40121) [filebeat][filestream] Enable status reporter for filestream input

CHANGELOG.next.asciidoc

@@ -29,6 +29,7 @@ https://github.com/elastic/beats/compare/v8.8.1\...main[Check the HEAD diff]
 - Update Salesforce module to use new Salesforce input. {pull}37509[37509]
 - Tag events that come from a filestream in "take over" mode. {pull}39828[39828]
 - Fix high IO and handling of a corrupted registry log file. {pull}35893[35893]
+- Filebeat, when running with Elastic-Agent, reports status for Filestream input. {pull}40121[40121]
 - Enable file ingestion to report detailed status to Elastic Agent {pull}40075[40075]
 - Fix filestream's registry GC: registry entries will never be removed if clean_inactive is set to "-1". {pull}40258[40258]
 

filebeat/input/filestream/input.go

@@ -34,6 +34,7 @@ import (
 	"github.com/elastic/beats/v7/libbeat/common/file"
 	"github.com/elastic/beats/v7/libbeat/common/match"
 	"github.com/elastic/beats/v7/libbeat/feature"
+	"github.com/elastic/beats/v7/libbeat/management/status"
 	"github.com/elastic/beats/v7/libbeat/reader"
 	"github.com/elastic/beats/v7/libbeat/reader/debug"
 	"github.com/elastic/beats/v7/libbeat/reader/parser"
@@ -164,7 +165,11 @@ func (inp *filestream) Run(
 	})
 	defer streamCancel()
 
-	return inp.readFromSource(ctx, log, r, fs.newPath, state, publisher, metrics)
+	if err := inp.readFromSource(ctx, log, r, fs.newPath, state, publisher, metrics); err != nil {
+		ctx.UpdateStatus(status.Degraded, fmt.Sprintf("error while reading from source: %v", err))
+		return err
+	}
+	return nil
 }
 
 func initState(log *logp.Logger, c loginp.Cursor, s fileSource) state {

filebeat/input/filestream/internal/input-logfile/harvester.go

@@ -28,6 +28,7 @@ import (
 	"github.com/elastic/beats/v7/filebeat/input/filestream/internal/task"
 	inputv2 "github.com/elastic/beats/v7/filebeat/input/v2"
 	"github.com/elastic/beats/v7/libbeat/beat"
+	"github.com/elastic/beats/v7/libbeat/management/status"
 	"github.com/elastic/elastic-agent-libs/logp"
 	"github.com/elastic/go-concert/ctxtool"
 )
@@ -204,7 +205,7 @@ func startHarvester(
 			if errors.Is(err, ErrHarvesterAlreadyRunning) {
 				return nil
 			}
-
+			ctx.UpdateStatus(status.Degraded, fmt.Sprintf("error while adding new reader to the bookkeeper %v", err))
 			return fmt.Errorf("error while adding new reader to the bookkeeper %w", err)
 		}
 
@@ -214,6 +215,7 @@ func startHarvester(
 		resource, err := lock(ctx, hg.store, srcID)
 		if err != nil {
 			hg.readers.remove(srcID)
+			ctx.UpdateStatus(status.Degraded, fmt.Sprintf("error while locking resource: %v", err))
 			return fmt.Errorf("error while locking resource: %w", err)
 		}
 		defer releaseResource(resource)
@@ -223,6 +225,7 @@ func startHarvester(
 		})
 		if err != nil {
 			hg.readers.remove(srcID)
+			ctx.UpdateStatus(status.Degraded, fmt.Sprintf("error while connecting to output with pipeline: %v", err))
 			return fmt.Errorf("error while connecting to output with pipeline: %w", err)
 		}
 		defer client.Close()
@@ -234,6 +237,7 @@ func startHarvester(
 		err = hg.harvester.Run(ctx, src, cursor, publisher, metrics)
 		if err != nil && !errors.Is(err, context.Canceled) {
 			hg.readers.remove(srcID)
+			ctx.UpdateStatus(status.Degraded, fmt.Sprintf("error while running harvester: %v", err))
 			return fmt.Errorf("error while running harvester: %w", err)
 		}
 		// If the context was not cancelled it means that the Harvester is stopping because of

filebeat/input/filestream/internal/input-logfile/input.go

@@ -25,6 +25,7 @@ import (
 	input "github.com/elastic/beats/v7/filebeat/input/v2"
 	"github.com/elastic/beats/v7/libbeat/beat"
 	"github.com/elastic/beats/v7/libbeat/common/acker"
+	"github.com/elastic/beats/v7/libbeat/management/status"
 	"github.com/elastic/go-concert/ctxtool"
 )
 
@@ -53,6 +54,7 @@ func (inp *managedInput) Run(
 	ctx input.Context,
 	pipeline beat.PipelineConnector,
 ) (err error) {
+	ctx.UpdateStatus(status.Starting, "")
 	groupStore := inp.manager.getRetainedStore()
 	defer groupStore.Release()
 
@@ -85,6 +87,10 @@ func (inp *managedInput) Run(
 	defer prospectorStore.Release()
 	sourceStore := newSourceStore(prospectorStore, inp.sourceIdentifier)
 
+	// Mark it as running for now.
+	// Any errors encountered by harverter will change state to Degraded
+	ctx.UpdateStatus(status.Running, "")
+
 	inp.prospector.Run(ctx, sourceStore, hg)
 
 	// Notify the manager the input has stopped, currently that is used to