Send errors in API calls and bulker flushes to APM (#3053) (#3055)

* Send errors in API calls to APM

* Capture errors in bulker transactions

* Add changelog

(cherry picked from commit 2e7e33b)

Co-authored-by: Josh Dover <[email protected]>

changelog/fragments/1698163014-apm-errors.yaml

@@ -0,0 +1,32 @@
+# Kind can be one of:
+# - breaking-change: a change to previously-documented behavior
+# - deprecation: functionality that is being removed in a later release
+# - bug-fix: fixes a problem in a previous version
+# - enhancement: extends functionality but does not break or fix existing behavior
+# - feature: new functionality
+# - known-issue: problems that we are aware of in a given version
+# - security: impacts on the security of a product or a user’s deployment.
+# - upgrade: important information for someone upgrading from a prior version
+# - other: does not fit into any of the other categories
+kind: enhancement
+
+# Change summary; a 80ish characters long description of the change.
+summary: Send errors in API calls and bulker flushes to APM
+
+# Long description; in case the summary is not enough to describe the change
+# this field accommodate a description without length limits.
+# NOTE: This field will be rendered only for breaking-change and known-issue kinds at the moment.
+#description:
+
+# Affected component; a word indicating the component this changeset affects.
+component:
+
+# PR URL; optional; the PR number that added the changeset.
+# If not present is automatically filled by the tooling finding the PR where this changelog fragment has been added.
+# NOTE: the tooling supports backports, so it's able to fill the original PR number instead of the backport PR number.
+# Please provide it if you are adding a fragment for a different PR.
+pr: https://github.com/elastic/fleet-server/pull/3053
+
+# Issue URL; optional; the GitHub issue related to this changeset (either closes or is part of).
+# If not present is automatically filled by the tooling with the issue linked to the PR number.
+#issue: https://github.com/owner/repo/1234

internal/pkg/api/error.go

@@ -20,6 +20,7 @@ import (
 	"github.com/elastic/fleet-server/v7/internal/pkg/file/uploader"
 	"github.com/elastic/fleet-server/v7/internal/pkg/limit"
 	"github.com/elastic/fleet-server/v7/internal/pkg/logger"
+	"go.elastic.co/apm/v2"
 
 	"github.com/rs/zerolog"
 	"github.com/rs/zerolog/hlog"
@@ -513,6 +514,11 @@ func ErrorResp(w http.ResponseWriter, r *http.Request, err error) {
 		e = e.Int64(ECSEventDuration, time.Since(ts).Nanoseconds())
 	}
 	e.Msg("HTTP request error")
+
+	if (resp.StatusCode >= 500) {
+		apm.CaptureError(r.Context(), err).Send()
+	}
+
 	if rerr := resp.Write(w); rerr != nil {
 		zlog.Error().Err(rerr).Msg("fail writing error response")
 	}

internal/pkg/bulk/engine.go

@@ -318,6 +318,7 @@ func (b *Bulker) flushQueue(ctx context.Context, w *semaphore.Weighted, queue qu
 
 		if err != nil {
 			failQueue(queue, err)
+			apm.CaptureError(ctx, err).Send()
 		}
 
 		log.Trace().