Elasticsearch

The es output plugin, allows to ingest your records into a Elasticsearch database. The following instructions assumes that you have a fully 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". But it is also possible to serve Elasticsearch behind a reverse proxy on a subpath. This option defines such path on the fluent-bit side. It simply adds a path prefix in the indexing HTTP POST URI.

Empty string

Buffer_Size

Specify the buffer size used to read the response from the Elasticsearch HTTP service. This option is useful for debugging purposes where is required to read full responses, note that response size grows depending of the number of records inserted. To set an unlimited amount of memory set this value to False, otherwise the value must be according to the Unit Size specification.

4KB

Pipeline

Newer versions of Elasticsearch allows to setup filters called pipelines. This option allows to define which pipeline the database should use. For performance reasons is strongly suggested to do parsing and filtering on Fluent Bit side, avoid pipelines.

AWS_Auth

Enable AWS Sigv4 Authentication for Amazon ElasticSearch Service

Off

AWS_Region

Specify the AWS region for Amazon ElasticSearch Service

AWS_STS_Endpoint

Specify the custom sts endpoint to be used with STS API for Amazon ElasticSearch Service

AWS_Role_ARN

AWS IAM Role to assume to put records to your Amazon ES cluster

AWS_External_ID

External ID for the AWS IAM Role specified with aws_role_arn

HTTP_User

Optional username credential for Elastic X-Pack access

HTTP_Passwd

Password for user defined in HTTP_User

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 equals 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_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

Replace_Dots

When enabled, replace field name dots with underscore, required by Elasticsearch 2.0-2.3.

Off

Trace_Output

When enabled print the elasticsearch API calls to stdout (for diag only)

Off

Current_Time_Index

Use current time for index generation instead of message record

Off

Logstash_Prefix_Key

When included: the value in the record that belongs to the key will be looked up and over-write the Logstash_Prefix for index generation. If the key/value is not found in the record then the Logstash_Prefix option will act as a fallback. Nested keys are not supported (if desired, you can use the nest filter plugin to remove nesting)

The parameters index and type can be confusing if you are new to Elastic, if you have used a common relational database before, they can be compared to the database and table concepts. Also see the FAQ below

TLS / SSL

Elasticsearch output plugin supports TTL/SSL, for more details about the properties available and general configuration, please refer to the TLS/SSL section.

Getting Started

In order to insert records into a Elasticsearch service, you can 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) or 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 do:

$ 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 & Output sections:

[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 may generate messages where the field names contains dots, since Elasticsearch 2.0 this is not longer allowed, so the current es plugin replaces them with an underscore, e.g:

{"cpu0.p_cpu"=>17.000000}

becomes

{"cpu0_p_cpu"=>17.000000}

FAQ

Elasticsearch rejects requests saying "the final mapping would have more than 1 type"

Since Elasticsearch 6.0, you cannot create multiple types in a single index. This means that you cannot set up your configuration as below anymore.

[OUTPUT]
Name es
Match foo.*
Index search
Type type1
[OUTPUT]
Name es
Match bar.*
Index search
Type type2

If you see an error message like below, you'll need to fix your configuration to use a single type on each index.

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

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

Elasticsearch rejects requests saying "Document mapping type name can't start with '_'"

Fluent Bit v1.5 changed the default mapping type from flb_type to _doc, which matches the recommendation from Elasticsearch from version 6.2 forwards (see commit with rationale). This doesn't work in Elasticsearch versions 5.6 through 6.1 (see Elasticsearch discussion and fix). Ensure you set an explicit map (such as doc or flb_type) in the configuration, as seen on the last line:

[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

Fluent Bit + Amazon Elasticsearch Service

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

Fluent Bit supports sourcing AWS credentials from any of the standard sources (for example, an Amazon EKS IAM Role for a Service Account).

Example configuration:

[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

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