Documentation Grafana Cloud Instrument and send data Grafana Alloy Reference Components loki loki.source.gelf

loki.source.gelf

loki.source.gelf reads Graylog Extended Long Format (GELF) logs from a UDP listener and forwards them to other loki.* components.

Multiple loki.source.gelf components can be specified by giving them different labels and ports.

Usage

alloy Copy

loki.source.gelf "LABEL" {
  forward_to    = RECEIVER_LIST
}

Arguments

The component starts a new UDP listener and fans out log entries to the list of receivers passed in forward_to.

loki.source.gelf supports the following arguments:

NOTE: GELF logs can be sent uncompressed or compressed with GZIP or ZLIB. A job label is added with the full name of the component loki.source.gelf.LABEL.

The relabel_rules argument can make use of the rules export from a loki.relabel component to apply one or more relabling rules to log entries before they’re forward to the list of receivers specified in forward_to.

Incoming messages have the following internal labels available:

• __gelf_message_level: The GELF level as a string.
• __gelf_message_host: The host sending the GELF message.
• __gelf_message_host: The GELF level message version sent by the client.
• __gelf_message_facility: The GELF facility.

All labels starting with __ are removed prior to forwarding log entries. To keep these labels, relabel them using a loki.relabel component and pass its rules export to the relabel_rules argument.

Component health

loki.source.gelf is only reported as unhealthy if given an invalid configuration.

Debug Metrics

• gelf_target_entries_total (counter): Total number of successful entries sent to the GELF target.
• gelf_target_parsing_errors_total (counter): Total number of parsing errors while receiving GELF messages.

Example

alloy Copy

loki.relabel "gelf" {
  rule {
    source_labels = ["__gelf_message_host"]
    target_label  = "host"
  }
}

loki.source.gelf "listen"  {
  forward_to    = [loki.write.endpoint.receiver]
  relabel_rules = loki.relabel.gelf.rules
}

loki.write "endpoint" {
  endpoint {
    url ="loki:3100/api/v1/push"
  }
}

Compatible components

loki.source.gelf can accept arguments from the following components:

• Components that export Loki LogsReceiver