HTTP

The HTTP output plugin lets you flush your records into an HTTP endpoint. It issues a POST request with the data records in MessagePack (or JSON) format.

Configuration parameters

The plugin supports the following configuration parameters:

Key	Description	Default
host	IP address or hostname of the target HTTP Server.	127.0.0.1
http_User	Basic Auth username.	none
http_Passwd	Basic Auth password. Requires HTTP_User to be set.	none
AWS_Auth	Enable AWS SigV4 authentication.	false
AWS_Service	Specify the AWS service code of your service, used by SigV4 authentication (for example, es, xray.) Usually found in the service endpoint's subdomains, protocol://service-code.region-code.amazonaws.com.	none
AWS_Region	Specify the AWS region of your service, used by SigV4 authentication.	none
AWS_STS_Endpoint	Specify the custom STS endpoint to be used by STS API. Used with the AWS_Role_ARN option and by SigV4 authentication.	none
AWS_Role_ARN	AWS IAM Role to assume, used by SigV4 authentication.	none
AWS_External_ID	External ID for the AWS IAM Role specified with aws_role_arn, used by SigV4 authentication.	none
port	TCP port of the target HTTP Server.	80
Proxy	Specify an HTTP Proxy. The expected format of this value is http://HOST:PORT. HTTPS isn't supported. It's recommended to configure the HTTP proxy environment variables instead as they support both HTTP and HTTPS.	none
uri	Specify an optional HTTP URI for the target web server. For example, /somepath.	/
compress	Set payload compression mechanism. Allowed value: gzip.	none
format	Specify the data format to be used in the HTTP request body. Supported formats: gelf, json, json_stream, json_lines, msgpack.	msgpack
allow_duplicated_headers	Specify if duplicated headers are allowed. If a duplicated header is found, the latest key/value set is preserved.	true
log_response_payload	Specify if the response payload should be logged or not.	true
header_tag	Specify an optional HTTP header field for the original message tag.	none
header	Add a HTTP header key/value pair. Multiple headers can be set.	none
json_date_key	Specify the name of the time key in the output record. To disable the time key, set the value to false.	date
json_date_format	Specify the format of the date. Supported formats: double, epoch, iso8601, java_sql_timestamp.	double
gelf_timestamp_key	Specify the key to use for timestamp in gelf format.	none
gelf_host_key	Specify the key to use for the host in gelf format.	none
gelf_short_message_key	Specify the key to use as the short message in gelf format.	none
gelf_full_message_key	Specify the key to use for the full message in gelf format.	none
gelf_level_key	Specify the key to use for the level in gelf format.	none
body_key	Specify the key to use as the body of the request (must prefix with $). The key must contain either a binary or raw string, and the content type can be specified using headers_key, which must be passed whenever body_key is present. When this option is present, each msgpack record will create a separate request.	none
headers_key	Specify the key to use as the headers of the request (must prefix with $). The key must contain a map, which will have the contents merged on the request headers. This can be used for many purposes, such as specifying the content type of the data contained in body_key.	none
workers	The number of workers to perform flush operations for this output.	2

TLS / SSL

The HTTP output plugin supports TLS/SSL. For more details about the properties available and general configuration, see TLS/SSL.

Get started

To insert records into an HTTP server, you can run the plugin from the command line or through the configuration file.

Command line

The HTTP plugin can read the parameters from the command line through the -p argument (property) or setting them directly through the service URI. The URI format is the following:

http://host:port/something

Using the format specified, you could start Fluent Bit through:

fluent-bit -i cpu -t cpu -o http://192.168.2.3:80/something -m '*'

Configuration file

In your main configuration file append the following:

fluent-bit.yaml

pipeline:
  inputs:
    - name: cpu
      tag:  cpu
  outputs:
    - name: http
      match: '*'
      host: 192.168.2.3
      port: 80
      uri: /something

fluent-bit.conf

[INPUT]
  Name  cpu
  Tag   cpu

[OUTPUT]
  Name  http
  Match *
  Host  192.168.2.3
  Port  80
  URI   /something

By default, the URI becomes tag of the message, the original tag is ignored. To retain the tag, multiple configuration sections have to be made based and flush to more than one URI.

Another supported approach is the sending the original message tag in a configurable header. It's up to the receiver to do what it wants with that header field. For example, parse it and use it as the tag for example.

To configure this behaviour, add this configuration:

fluent-bit.yaml

pipeline:

  outputs:
    - name: http
      match: '*'
      host: 192.168.2.3
      port: 80
      uri: /something
      format: json
      header_tag: FLUENT-TAG

fluent-bit.conf

[OUTPUT]
  Name  http
  Match *
  Host  192.168.2.3
  Port  80
  URI   /something
  Format json
  header_tag  FLUENT-TAG

Provided you are using Fluentd as data receiver, you can combine in_http and out_rewrite_tag_filter to make use of this HTTP header.

<source>
  @type http
  add_http_headers true
</source>

<match something>
  @type rewrite_tag_filter
  <rule>
    key HTTP_FLUENT_TAG
    pattern /^(.*)$/
    tag $1
  </rule>
</match>

Fluent Bit overrides the tag, which is from URI path, with a custom header.

Add a header

This example adds a header.

fluent-bit.yaml

pipeline:

  outputs:
    - name: http
      match: '*'
      host: 127.0.0.1
      port: 9000
      header:
        - X-Key-A Value_A
        - X-Key-B Value_B
      uri: /something

fluent-bit.conf

[OUTPUT]
  Name           http
  Match          *
  Host           127.0.0.1
  Port           9000
  Header         X-Key-A Value_A
  Header         X-Key-B Value_B
  URI            /something

Sumo Logic HTTP collector

The following is a suggested configuration for Sumo Logic using json_lines with iso8601 timestamps. The PrivateKey is specific to a configured HTTP collector.

fluent-bit.yaml

pipeline:

  outputs:
    - name: http
      match: '*'
      host: collectors.au.sumologic.com
      port: 443
      uri: /receiver/v1/http/[PrivateKey]
      format: json_lines
      json_date_key: timestamp
      json_date_format: iso8601

fluent-bit.conf

[OUTPUT]
  Name             http
  Match            *
  Host             collectors.au.sumologic.com
  Port             443
  URI              /receiver/v1/http/[PrivateKey]
  Format           json_lines
  Json_date_key    timestamp
  Json_date_format iso8601

A sample Sumo Logic query for the CPU input. (Requires json_lines format with iso8601 date format for the timestamp field).

_sourcecategory="my_fluent_bit"
| json "cpu_p" as cpu
| timeslice 1m
| max(cpu) as cpu group by _timeslice