loki built-in output plugin allows you to send your log or events to a Loki service. It support data enrichment with Kubernetes labels, custom label keys and Tenant ID within others.key=value pairs. In addition to fixed parameters, it also allows to add custom record keys (similar to label_keys property). More details in the Labels section.json or key_value. If set to json, the log line sent to Loki will be the Fluent Bit record dumped as JSON. If set to key_value, the log line will be each item in the record concatenated together (separated by a single space) in the format.job and the value of the record key called stream , your labels configuration properties might look as follows:job has the value fluentbit and the second label is configured to access the nested map called sub targeting the value of the key stream . Note that the second label name must starts with a $, that means that's a Record Accessor pattern so it provide you the ability to retrieve values from nested maps by using the key names.label_keys propertylabel_keys allow to specify multiple record keys that needs to be placed as part of the outgoing Stream Labels, yes, this is a similar feature than the one explained above in the labels property. Consider this as another way to set a record key in the Stream, but with the limitation that you cannot use a custom name for the key value.auto_kubernetes_labels which will auto-populate the streams with the Pod labels for you. Consider the following configuration:out_loki.conf: