feat: add app_name as a service label (#13660)

docs/sources/shared/configuration.md

@@ -3325,7 +3325,7 @@ The `limits_config` block configures global and per-tenant limits in Loki. The v
 # list to service_name. If none of the configured labels exist in the stream,
 # label is set to unknown_service. Empty list disables setting the label.
 # CLI flag: -validation.discover-service-name
-[discover_service_name: <list of strings> | default = [service app application name app_kubernetes_io_name container container_name k8s_container_name component workload job k8s_job_name]]
+[discover_service_name: <list of strings> | default = [service app application app_name name app_kubernetes_io_name container container_name k8s_container_name component workload job k8s_job_name]]
 
 # Discover and add log levels during ingestion, if not present already. Levels
 # would be added to Structured Metadata with name

pkg/validation/limits.go

@@ -271,6 +271,7 @@ func (l *Limits) RegisterFlags(f *flag.FlagSet) {
 		"service",
 		"app",
 		"application",
+		"app_name",
 		"name",
 		"app_kubernetes_io_name",
 		"container",