change error handling, clean up log messages

libbeat/idxmgmt/index_support.go

@@ -232,6 +232,8 @@ func (m *indexManager) VerifySetup(loadTemplate, loadLifecycle LoadMode) (bool,
 	if !templateComponent.load {
 		warn += "Template loading not enabled.\n"
 	}
+	// remove last newline so we don't get weird formatting when this is printed to the console
+	warn = strings.TrimSuffix(warn, "\n")
 	return warn == "", warn
 }
 

libbeat/idxmgmt/lifecycle/config.go

@@ -50,8 +50,9 @@ type LifecycleConfig struct {
 // RawConfig half-unpacks the policy config, allowing us to tell if a user has explicitly
 // enabled a given config value
 type RawConfig struct {
-	ILM *config.C `config:"setup.ilm"`
-	DSL *config.C `config:"setup.dsl"`
+	ILM          *config.C `config:"setup.ilm"`
+	DSL          *config.C `config:"setup.dsl"`
+	TemplateName string    `config:"setup.template.name"`
 }
 
 // DefaultILMPolicy defines the default policy to be used if no custom policy is

libbeat/idxmgmt/lifecycle/es_client_handler.go

@@ -23,6 +23,7 @@ import (
 	"net/http"
 
 	"github.com/elastic/beats/v7/libbeat/beat"
+	"github.com/elastic/elastic-agent-libs/logp"
 	"github.com/elastic/elastic-agent-libs/mapstr"
 )
 
@@ -41,11 +42,11 @@ type ESClientHandler struct {
 // NewESClientHandler initializes and returns an ESClientHandler
 func NewESClientHandler(c ESClient, info beat.Info, cfg RawConfig) (*ESClientHandler, error) {
 	if !cfg.DSL.Enabled() && cfg.ILM.Enabled() && c.IsServerless() {
-		return nil, fmt.Errorf("ILM is enabled but %s is connected to a serverless instance; ILM isn't supported on Serverless Elasticsearch", info.Beat)
+		return nil, fmt.Errorf("ILM is enabled/configured but %s is connected to a serverless instance; ILM isn't supported on Serverless Elasticsearch. Configure DSL or set setup.ilm.enabled to false", info.Beat)
 	}
 
 	if !cfg.ILM.Enabled() && cfg.DSL.Enabled() && !c.IsServerless() {
-		return nil, fmt.Errorf("DSL is enabled but %s is connected to a stateful instance; DSL is only supported on Serverless Elasticsearch", info.Beat)
+		return nil, fmt.Errorf("DSL is enabled/configured but %s is connected to a stateful instance; DSL is only supported on Serverless Elasticsearch. Configure ILM or set setup.dsl.enabled to false", info.Beat)
 	}
 
 	if cfg.ILM.Enabled() && cfg.DSL.Enabled() {
@@ -79,6 +80,14 @@ func NewESClientHandler(c ESClient, info beat.Info, cfg RawConfig) (*ESClientHan
 	if name == "" && lifecycleCfg.Enabled {
 		return nil, errors.New("could not generate usable policy name from config. Check setup.*.policy_name fields")
 	}
+	// deal with conflicts between policy name and template name
+	// under serverless, it doesn't make sense to have a policy name that differs from the template name
+	// if the user has set both to different values, throw a warning, as overwrite operations will probably fail
+	if c.IsServerless() {
+		if cfg.TemplateName != "" && cfg.TemplateName != name {
+			logp.L().Warnf("policy name is %s but template name is %s; under serverless, non-default template and policy names should be the same. Updates & overwrites may not work.")
+		}
+	}
 
 	// set defaults
 	defaultPolicy := DefaultILMPolicy

libbeat/template/load.go

@@ -148,7 +148,7 @@ func (l *ESLoader) Load(config TemplateConfig, info beat.Info, fields []byte, mi
 	}
 	if dataStreamExist {
 		l.log.Infof("Data stream with name %q already exists.", templateName)
-		// for serverless, we can update the lifetimes safely
+		// for serverless, we can update the lifecycle policy safely
 		// Note that updating the lifecycle will delete older documents
 		// if the policy requires it; i.e, changing the data_retention from 10d to 7d
 		// will delete the documents older than 7 days.