loki.relabel.md

---

title: loki.relabel

---

loki.relabel

The loki.relabel component rewrites the label set of each log entry passed to its receiver by applying one or more relabeling rules and forwards the results to the list of receivers in the component's arguments.

If no labels remain after the relabeling rules are applied, then the log entries are dropped.

The most common use of loki.relabel is to filter log entries or standardize the label set that is passed to one or more downstream receivers. The rule blocks are applied to the label set of each log entry in order of their appearance in the configuration file. The configured rules can be retrieved by calling the function in the rules export field.

If you're looking for a way to process the log entry contents, take a look at [the loki.process component][loki.process] instead.

[loki.process]: {{< relref "./loki.process.md" >}}

Multiple loki.relabel components can be specified by giving them different labels.

Usage

loki.relabel "LABEL" {
  forward_to = RECEIVER_LIST

  rule {
    ...
  }

  ...
}

Arguments

The following arguments are supported:

Name	Type	Description	Default	Required
forward_to	list(receiver)	Where to forward log entries after relabeling.		yes
max_cache_size	int	The maximum number of elements to hold in the relabeling cache	10,000	no

Blocks

The following blocks are supported inside the definition of loki.relabel:

Hierarchy	Name	Description	Required
rule	rule	Relabeling rules to apply to received log entries.	no

rule block

{{< docs/shared lookup="flow/reference/components/rule-block.md" source="agent" >}}

Exported fields

The following fields are exported and can be referenced by other components:

Name	Type	Description
receiver	receiver	The input receiver where log lines are sent to be relabeled.
rules	RelabelRules	The currently configured relabeling rules.

Component health

loki.relabel is only reported as unhealthy if given an invalid configuration. In those cases, exported fields are kept at their last healthy values.

Debug information

loki.relabel does not expose any component-specific debug information.

Debug metrics

• loki_relabel_entries_processed (counter): Total number of log entries processed.

• loki_relabel_entries_written (counter): Total number of log entries forwarded.

• loki_relabel_cache_misses (counter): Total number of cache misses.

• loki_relabel_cache_hits (counter): Total number of cache hits.

• loki_relabel_cache_size (gauge): Total size of relabel cache.

Example

The following example creates a loki.relabel component that only forwards entries whose 'level' value is set to 'error'.

loki.relabel "keep_error_only" {
  forward_to = [loki.write.onprem.receiver]

  rule {
    action        = "keep"
    source_labels = ["level"]
    regex         = "error"
  }
}