From d2b785acb1aeae9d83232dfabc73a79b10ecbc9f Mon Sep 17 00:00:00 2001
From: "mergify[bot]" <37929162+mergify[bot]@users.noreply.github.com>
Date: Wed, 4 Dec 2024 09:27:24 -0600
Subject: [PATCH] don't panic loading twice (#41857) (#41872)

(cherry picked from commit ab0f3c836e4578b10fa59a0423fdc9ef83f89d66)

Co-authored-by: Lee E Hinman <57081003+leehinman@users.noreply.github.com>
---
 CHANGELOG.next.asciidoc              |  1 +
 libbeat/processors/namespace.go      | 11 ++++++++---
 libbeat/processors/namespace_test.go |  2 +-
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/CHANGELOG.next.asciidoc b/CHANGELOG.next.asciidoc
index 146fc8ba1b7c..ad659714f8a9 100644
--- a/CHANGELOG.next.asciidoc
+++ b/CHANGELOG.next.asciidoc
@@ -110,6 +110,7 @@ https://github.com/elastic/beats/compare/v8.8.1\...main[Check the HEAD diff]
 - Add `translate_ldap_attribute` processor. {pull}41472[41472]
 - Remove unnecessary debug logs during idle connection teardown {issue}40824[40824]
 - Fix incorrect cloud provider identification in add_cloud_metadata processor using provider priority mechanism {pull}41636[41636]
+- Prevent panic if libbeat processors are loaded more than once. {issue}41475[41475] {pull}41857[51857]
 
 *Auditbeat*
 
diff --git a/libbeat/processors/namespace.go b/libbeat/processors/namespace.go
index 0ccf1deda458..5d015b16bcf1 100644
--- a/libbeat/processors/namespace.go
+++ b/libbeat/processors/namespace.go
@@ -38,6 +38,11 @@ type pluginer interface {
 	Plugin() Constructor
 }
 
+var (
+	ErrExistsAlready           error = errors.New("exists already")
+	ErrPluginAlreadyRegistered error = errors.New("non-namespace plugin already registered")
+)
+
 func NewNamespace() *Namespace {
 	return &Namespace{
 		reg: map[string]pluginer{},
@@ -47,7 +52,7 @@ func NewNamespace() *Namespace {
 func (ns *Namespace) Register(name string, factory Constructor) error {
 	p := plugin{NewConditional(factory)}
 	names := strings.Split(name, ".")
-	if err := ns.add(names, p); err != nil {
+	if err := ns.add(names, p); err != nil && !errors.Is(err, ErrExistsAlready) && !errors.Is(err, ErrPluginAlreadyRegistered) {
 		return fmt.Errorf("plugin %s registration fail %w", name, err)
 	}
 	return nil
@@ -59,7 +64,7 @@ func (ns *Namespace) add(names []string, p pluginer) error {
 	// register plugin if intermediate node in path being processed
 	if len(names) == 1 {
 		if _, found := ns.reg[name]; found {
-			return fmt.Errorf("%v exists already", name)
+			return fmt.Errorf("%s %w", name, ErrExistsAlready)
 		}
 
 		ns.reg[name] = p
@@ -71,7 +76,7 @@ func (ns *Namespace) add(names []string, p pluginer) error {
 	if found {
 		ns, ok := tmp.(*Namespace)
 		if !ok {
-			return errors.New("non-namespace plugin already registered")
+			return ErrPluginAlreadyRegistered
 		}
 		return ns.add(names[1:], p)
 	}
diff --git a/libbeat/processors/namespace_test.go b/libbeat/processors/namespace_test.go
index 07c62328c2c1..221cee9b2e37 100644
--- a/libbeat/processors/namespace_test.go
+++ b/libbeat/processors/namespace_test.go
@@ -65,7 +65,7 @@ func TestNamespaceRegisterFail(t *testing.T) {
 	fatalError(t, err)
 
 	err = ns.Register("test", newTestFilterRule)
-	assert.Error(t, err)
+	assert.NoError(t, err)
 }
 
 func TestNamespaceError(t *testing.T) {