Elasticsearch

Send logs to Elasticsearch (including Amazon OpenSearch Service)

The es output plugin lets you ingest your records into anElasticsearch database. To use this plugin, you must have an operational Elasticsearch service running in your environment.

Configuration Parameters

Key	Description	Default
Host	IP address or hostname of the target Elasticsearch instance	127.0.0.1
Port	TCP port of the target Elasticsearch instance	9200
Path	Elasticsearch accepts new data on HTTP query path /_bulk. You can also serve Elasticsearch behind a reverse proxy on a sub-path. Define the path by adding a path prefix in the indexing HTTP POST URI.	Empty string
compress	Set payload compression mechanism. Option available is gzip.	none
Buffer_Size	Specify the buffer size used to read the response from the Elasticsearch HTTP service. Use for debugging purposes where required to read full responses. Response size grows depending of the number of records inserted. To use an unlimited amount of memory, set this value to False. Otherwise set the value according to the Unit Size.	512KB
Pipeline	Define which pipeline the database should use. For performance reasons, it's strongly suggested to do parsing and filtering on Fluent Bit side, and avoid pipelines.	none
AWS_Auth	Enable AWS Sigv4 Authentication for Amazon OpenSearch Service.	Off
AWS_Region	Specify the AWS region for Amazon OpenSearch Service.	none
AWS_STS_Endpoint	Specify the custom STS endpoint to be used with STS API for Amazon OpenSearch Service	none
AWS_Role_ARN	AWS IAM Role to assume to put records to your Amazon cluster	none
AWS_External_ID	External ID for the AWS IAM Role specified with aws_role_arn	none
AWS_Service_Name	Service name to use in AWS Sigv4 signature. For integration with Amazon OpenSearch Serverless, set to aoss. See Amazon OpenSearch Serverless for more information.	es
AWS_Profile	AWS profile name	default
Cloud_ID	If using Elastic's Elasticsearch Service you can specify the cloud_id of the cluster running. The string has the format <deployment_name>:<base64_info>. Once decoded, the base64_info string has the format <deployment_region>$<elasticsearch_hostname>$<kibana_hostname>.	none
Cloud_Auth	Specify the credentials to use to connect to Elastic's Elasticsearch Service running on Elastic Cloud	none
HTTP_User	Optional username credential for Elastic X-Pack access	none
HTTP_Passwd	Password for user defined in HTTP_User	none
Index	Index name	fluent-bit
Type	Type name	_doc
Logstash_Format	Enable Logstash format compatibility. This option takes a Boolean value: True/False, On/Off	Off
Logstash_Prefix	When Logstash_Format is enabled, the Index name is composed using a prefix and the date, e.g: If Logstash_Prefix is equal to mydata your index will become mydata-YYYY.MM.DD. The last string appended belongs to the date when the data is being generated.	logstash
Logstash_Prefix_Key	When included: the value of the key in the record will be evaluated as key reference and overrides Logstash_Prefix for index generation. If the key/value isn't found in the record then the Logstash_Prefix option will act as a fallback. The parameter is expected to be a record accessor.	none
Logstash_Prefix_Separator	Set a separator between Logstash_Prefix and date.	-
Logstash_DateFormat	Time format based on strftime to generate the second part of the Index name.	%Y.%m.%d
Time_Key	When Logstash_Format is enabled, each record will get a new timestamp field. The Time_Key property defines the name of that field.	@timestamp
Time_Key_Format	When Logstash_Format is enabled, this property defines the format of the timestamp.	%Y-%m-%dT%H:%M:%S
Time_Key_Nanos	When Logstash_Format is enabled, enabling this property sends nanosecond precision timestamps.	Off
Include_Tag_Key	When enabled, it append the Tag name to the record.	Off
Tag_Key	When Include_Tag_Key is enabled, this property defines the key name for the tag.	_flb-key
Generate_ID	When enabled, generate _id for outgoing records. This prevents duplicate records when retrying ES.	Off
Id_Key	If set, _id will be the value of the key from incoming record and Generate_ID option is ignored.	none
Write_Operation	Write_operation can be any of: create, index, update, upsert.	create
Replace_Dots	When enabled, replace field name dots with underscore. Required by Elasticsearch 2.0-2.3.	Off
Trace_Output	Print all ElasticSearch API request payloads to stdout for diagnostics.	Off
Trace_Error	If ElasticSearch returns an error, print the ElasticSearch API request and response for diagnostics.	Off
Current_Time_Index	Use current time for index generation instead of message record.	Off
Suppress_Type_Name	When enabled, mapping types is removed and Type option is ignored. Elasticsearch 8.0.0 or higher no longer supports mapping types, and is set to On.	Off
Workers	The number of workers to perform flush operations for this output.	2

If you have used a common relational database, the parameters index and type can be compared to the database and table concepts.

TLS / SSL

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

write_operation

The write_operation can be any of:

Operation	Description
create	Adds new data. If the data already exists (based on its id), the op is skipped.
index	New data is added while existing data (based on its id) is replaced (reindexed).
update	Updates existing data (based on its id). If no data is found, the op is skipped.
upsert	Merge or insert if the data doesn't exist, updates if the data exists (based on its id).

Id_Key or Generate_ID is required for update and upsert.

Get started

To insert records into an Elasticsearch service, you run the plugin from the command line or through the configuration file:

Command Line

The es plugin can read the parameters from the command line in two ways:

• Through the -p argument (property).

• Setting them directly through the service URI.

The URI format is the following:

es://host:port/index/type

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

fluent-bit -i cpu -t cpu -o es://192.168.2.3:9200/my_index/my_type \
    -o stdout -m '*'

Which is similar to the following command:

fluent-bit -i cpu -t cpu -o es -p Host=192.168.2.3 -p Port=9200 \
    -p Index=my_index -p Type=my_type -o stdout -m '*'

Configuration File

In your main configuration file append the following Input and Output sections.

fluent-bit.yaml

pipeline:
    inputs:
        - name: cpu
          tag: cpu
          
    outputs:
        - name: es
          match: '*'
          host: 192.168.2.3
          port: 9200
          index: my_index
          type: my_type

fluent-bit.conf

[INPUT]
    Name  cpu
    Tag   cpu

[OUTPUT]
    Name  es
    Match *
    Host  192.168.2.3
    Port  9200
    Index my_index
    Type  my_type

About Elasticsearch field names

Some input plugins can generate messages where the field names contains dots. For Elasticsearch 2.0, this isn't allowed. The current es plugin replaces them with an underscore:

{"cpu0.p_cpu"=>17.000000}

becomes

{"cpu0_p_cpu"=>17.000000}

Use Fluent Bit ElasticSearch plugin with other services

Connect to Amazon OpenSearch or Elastic Cloud with the ElasticSearch plugin.

Amazon OpenSearch Service

The Amazon OpenSearch Service adds an extra security layer where HTTP requests must be signed with AWS Sigv4. Fluent Bit v1.5 introduced full support for Amazon OpenSearch Service with IAM Authentication.

See details on how AWS credentials are fetched.

Example configuration:

fluent-bit.yaml

pipeline:
    inputs:
        ...
          
    outputs:
        - name: es
          match: '*'
          host: vpc-test-domain-ke7thhzoo7jawsrhmm6mb7ite7y.us-west-2.es.amazonaws.com
          port: 443
          index: my_index
          type: my_type
          aws_auth: on
          aws_region: us-west-2
          tls: on

fluent-bit.conf

[OUTPUT]
    Name  es
    Match *
    Host  vpc-test-domain-ke7thhzoo7jawsrhmm6mb7ite7y.us-west-2.es.amazonaws.com
    Port  443
    Index my_index
    Type  my_type
    AWS_Auth On
    AWS_Region us-west-2
    tls     On

Be aware that the Port is set to 443, tls is enabled, and AWS_Region is set.

Use Fluent Bit with Elastic Cloud

Fluent Bit supports connecting toElastic Cloud by providing the cloud_id and the cloud_auth settings. cloud_auth uses theelastic user and password provided when the cluster was created. For details refer to theCloud ID usage page.

Example configuration:

fluent-bit.yaml

pipeline:
    inputs:
        ...
          
    outputs:
        - name: es
          include_tag_key: true
          tag_key: tags
          tls: on
          tls.verify: off
          cloud_id: 'elastic-obs-deployment:ZXVybxxxxxxxxxxxg=='
          cloud_auth: 'elastic:2vxxxxxxxxYV'

fluent-bit.conf

[OUTPUT]
    Name es
    Include_Tag_Key true
    Tag_Key tags
    tls On
    tls.verify Off
    Suppress_Type_Name On
    cloud_id elastic-obs-deployment:ZXVybxxxxxxxxxxxg==
    cloud_auth elastic:2vxxxxxxxxYV

In Elastic Cloud version 8 and great, the type option must be removed by settingSuppress_Type_Name On.

Without this you will see errors like:

{"error":{"root_cause":[{"type":"illegal_argument_exception","reason":"Action/metadata line [1] contains an unknown parameter [_type]"}],"type":"illegal_argument_exception","reason":"Action/metadata line [1] contains an unknown parameter [_type]"},"status":400}

Troubleshooting

Use the following information to help resolve errors using the ElasticSearch plugin.

Using multiple types in a single index

Elasticsearch 6.0 can't create multiple types in a single index. An error message like the following indicates you need to update your configuration to use a single type on each index.

Rejecting mapping update to [products] as the final mapping would have more than 1 type:

This means that you can't set up your configuration like the following:.

fluent-bit.yaml

pipeline:
    inputs:
        ...
          
    outputs:
        - name: es
          match: 'foo.*'
          index: search
          type: type1

        - name: es
          match: 'bar.*'
          index: search
          type: type2

fluent-bit.conf

[OUTPUT]
    Name  es
    Match foo.*
    Index search
    Type  type1

[OUTPUT]
    Name  es
    Match bar.*
    Index search
    Type  type2

For details, read the official blog post on that issue.

Mapping type names can't start with underscores (_)

Fluent Bit v1.5 changed the default mapping type from flb_type to _doc, matching the recommendation from Elasticsearch for version 6.2 and greater (see commit with rationale).

This doesn't work in Elasticsearch versions 5.6 through 6.1 (discussion and fix).

Ensure you set an explicit map such as doc or flb_type in the configuration, as seen on the last line:

fluent-bit.yaml

pipeline:
    inputs:
        ...
          
    outputs:
        - name: es
          match: '*'
          host: vpc-test-domain-ke7thhzoo7jawsrhmm6mb7ite7y.us-west-2.es.amazonaws.com
          port: 443
          index: my_index
          aws_auth: on
          aws_region: us-west-2
          tls: on
          type: doc

fluent-bit.conf

[OUTPUT]
    Name  es
    Match *
    Host  vpc-test-domain-ke7thhzoo7jawsrhmm6mb7ite7y.us-west-2.es.amazonaws.com
    Port  443
    Index my_index
    AWS_Auth On
    AWS_Region us-west-2
    tls   On
    Type  doc

Validation failures

In Fluent Bit v1.8.2 and greater, Fluent Bit started using create method (instead of index) for data submission. This makes Fluent Bit compatible with Datastream, introduced in Elasticsearch 7.9. You might see errors like:

Validation Failed: 1: an id must be provided if version type or value are set

If you see action_request_validation_exception errors on your pipeline with Fluent Bit versions greater than v1.8.2, correct them by turning on Generate_ID as follows:

fluent-bit.yaml

pipeline:
    inputs:
        ...
          
    outputs:
        - name: es
          match: '*'
          host: 192.168.12.1
          generate_id: on

fluent-bit.conf

[OUTPUT]
    Name es
    Match *
    Host  192.168.12.1
    Generate_ID on

Logstash_Prefix_Key

The following snippet demonstrates using the namespace name as extracted by thekubernetes filter as logstash prefix:

fluent-bit.yaml

pipeline:
    inputs:
        ...
          
    outputs:
        - name: es
          match: '*'
          # ...
          logstash_prefix: logstash
          logstash_prefix_key: $kubernetes['namespace_name'] 
          # ...

fluent-bit.conf

[OUTPUT]
    Name es
    Match *
    # ...
    Logstash_Prefix logstash
    Logstash_Prefix_Key $kubernetes['namespace_name']
    # ...

For records that don't have the field kubernetes.namespace_name, the default prefixlogstash will be used.