Prometheus remote write

An input plugin to ingest payloads of Prometheus remote write

Supported event types: metrics

The Prometheus remote write input plugin lets you ingest a payload in the Prometheus remote-write format. A remote-write sender can transmit data to Fluent Bit.

Configuration parameters

The table below includes both:

• settings specific to the Prometheus remote write input plugin

• shared http_server.* listener settings that are used by several HTTP-based inputs

For a cross-plugin explanation of the shared listener settings, see Shared HTTP listener settings for inputs.

Key	Description	Default
buffer_chunk_size	Sets the chunk size for incoming data. These chunks are then stored and managed in the space specified by buffer_max_size. Compatibility alias for http_server.buffer_chunk_size.	512K
buffer_max_size	Specifies the maximum buffer size to receive a request. Compatibility alias for http_server.buffer_max_size.	4M
http2	Enable HTTP/2 support. Compatibility alias for http_server.http2.	true
http_server.max_connections	Maximum number of concurrent active HTTP connections. 0 means unlimited.	0
http_server.workers	Number of HTTP listener worker threads.	1
http_server.ingress_queue_event_limit	Maximum number of deferred ingress queue entries. Applies only when http_server.workers is greater than 1.	8192
http_server.ingress_queue_byte_limit	Maximum size of the deferred ingress queue. Applies only when http_server.workers is greater than 1.	256M
listen	The address to listen on.	0.0.0.0
port	The port to listen on.	8080
successful_response_code	Specifies the success response code. Supported values are 200, 201, and 204.	201
tag_from_uri	If true, a tag will be created from the uri parameter (for example, api_prom_push from /api/prom/push), and any tag specified in the configuration will be ignored. If false, you must provide a tag in the configuration for this plugin.	true
threaded	Specifies whether to run this input in its own thread.	false
uri	Specifies an optional HTTP URI for the target web server listening for Prometheus remote write payloads (for example, /api/prom/push).	none

The http_server.ingress_queue_event_limit and http_server.ingress_queue_byte_limit settings matter only when http_server.workers is greater than 1.

Configuration file

The following examples are sample configuration files for this input plugin:

fluent-bit.yaml

pipeline:
  inputs:
    - name: prometheus_remote_write
      listen: 127.0.0.1
      port: 8080
      uri: /api/prom/push

  outputs:
    - name: stdout
      match: '*'

fluent-bit.conf

These sample configurations configure Fluent Bit to listen for data on port 8080. You can send payloads in Prometheus remote-write format to the endpoint /api/prom/push.

Examples

Communicate with TLS

The Prometheus remote write input plugin supports TLS and SSL. For more details about the properties available and general configuration, refer to the Transport security documentation.

To communicate with TLS, you must use these TLS-related parameters:

fluent-bit.yaml

pipeline:
  inputs:
    - name: prometheus_remote_write
      listen: 127.0.0.1
      port: 8080
      uri: /api/prom/push
      tls: on
      tls.crt_file: /path/to/certificate.crt
      tls.key_file: /path/to/certificate.key

fluent-bit.conf

Now, you should be able to send data over TLS to the remote-write input.