Don't include full ES index template in errors

CHANGELOG.next.asciidoc

@@ -242,6 +242,7 @@ https://github.com/elastic/beats/compare/v7.0.0-alpha2...master[Check the HEAD d
 - Fix handling of `file_selectors` in aws-s3 input. {pull}25792[25792]
 - Fix ILM alias creation when write alias exists and initial index does not exist {pull}26143[26143]
 - Include date separator in the filename prefix of `dateRotator` to make sure nothing gets purged accidentally {pull}26176[26176]
+- Omit full index template from errors that occur while loading the template. {pull}25743[25743]
 - In the script processor, the `decode_xml` and `decode_xml_wineventlog` processors are now available as `DecodeXML` and `DecodeXMLWineventlog` respectively.
 
 *Auditbeat*

libbeat/template/load.go

@@ -40,7 +40,7 @@ var (
 	}
 )
 
-//Loader interface for loading templates
+// Loader interface for loading templates.
 type Loader interface {
 	Load(config TemplateConfig, info beat.Info, fields []byte, migration bool) error
 }
@@ -94,15 +94,15 @@ func newTemplateBuilder() *templateBuilder {
 	return &templateBuilder{log: logp.NewLogger("template")}
 }
 
-// Load checks if the index mapping template should be loaded
+// Load checks if the index mapping template should be loaded.
 // In case the template is not already loaded or overwriting is enabled, the
-// template is built and written to index
+// template is built and written to index.
 func (l *ESLoader) Load(config TemplateConfig, info beat.Info, fields []byte, migration bool) error {
 	if l.client == nil {
 		return errors.New("can not load template without active Elasticsearch client")
 	}
 
-	//build template from config
+	// build template from config
 	tmpl, err := l.builder.template(config, info, l.client.GetVersion(), migration)
 	if err != nil || tmpl == nil {
 		return err
@@ -120,19 +120,19 @@ func (l *ESLoader) Load(config TemplateConfig, info beat.Info, fields []byte, mi
 	}
 
 	if exists && !config.Overwrite {
-		l.log.Infof("Template %s already exists and will not be overwritten.", templateName)
+		l.log.Infof("Template %q already exists and will not be overwritten.", templateName)
 		return nil
 	}
 
-	//loading template to ES
+	// loading template to ES
 	body, err := l.builder.buildBody(tmpl, config, fields)
 	if err != nil {
 		return err
 	}
 	if err := l.loadTemplate(templateName, config.Type, body); err != nil {
-		return fmt.Errorf("could not load template. Elasticsearch returned: %v. Template is: %s", err, body.StringToPrint())
+		return fmt.Errorf("failed to load template: %w", err)
 	}
-	l.log.Infof("template with name '%s' loaded.", templateName)
+	l.log.Infof("Template with name %q loaded.", templateName)
 	return nil
 }
 

libbeat/tests/system/test_template.py

@@ -107,7 +107,7 @@ def test_json_template(self):
         proc = self.start_beat()
         self.wait_until(lambda: self.log_contains("mockbeat start running."))
         self.wait_until(lambda: self.log_contains("Loading json template from file"))
-        self.wait_until(lambda: self.log_contains("template with name 'bla' loaded"))
+        self.wait_until(lambda: self.log_contains('Template with name "bla" loaded.'))
         proc.check_kill_and_wait()
 
         result = es.transport.perform_request('GET', '/_template/' + template_name)
@@ -149,7 +149,7 @@ def test_template_default(self):
         self.render_config()
         proc = self.start_beat()
         self.wait_until(lambda: self.log_contains("mockbeat start running."))
-        self.wait_until(lambda: self.log_contains("template with name 'mockbeat-9.9.9' loaded"))
+        self.wait_until(lambda: self.log_contains('Template with name "mockbeat-9.9.9" loaded.'))
         self.wait_until(lambda: self.log_contains("PublishEvents: 1 events have been published"))
         proc.check_kill_and_wait()