Configure the Elasticsearch output

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Running Elastic Agent in standalone mode is an advanced use case. The documentation is incomplete and not yet mature. When possible, we recommend using Fleet-managed agents instead of standalone mode.

The Elasticsearch output sends events directly to Elasticsearch by using the Elasticsearch HTTP API.

Compatibility: This output works with all compatible versions of Elasticsearch. See the Elastic Support Matrix.

This example configures an Elasticsearch output called default in the elastic-agent.yml file:

outputs:
  default:
    type: elasticsearch
    hosts: [127.0.0.1:9200]
    username: elastic
    password: changeme

Elasticsearch output configuration settings

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The elasticsearch output type supports the following settings, grouped by category. Many of these settings have sensible defaults that allow you to run Elastic Agent with minimal configuration.

Commonly used settings

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Setting Description

enabled

(boolean) Enables or disables the output. If set to false, the output is disabled.

Default: true

hosts

(list) The list of Elasticsearch nodes to connect to. The events are distributed to these nodes in round robin order. If one node becomes unreachable, the event is automatically sent to another node. Each Elasticsearch node can be defined as a URL or IP:PORT. For example: http://192.15.3.2, https://es.found.io:9230 or 192.24.3.2:9300. If no port is specified, 9200 is used.

When a node is defined as an IP:PORT, the scheme and path are taken from the protocol and path settings.

outputs:
  default:
    type: elasticsearch
    hosts: ["10.45.3.2:9220", "10.45.3.1:9230"] 
    protocol: https
    path: /elasticsearch

In this example, the Elasticsearch nodes are available at https://10.45.3.2:9220/elasticsearch and https://10.45.3.1:9230/elasticsearch.

protocol

(string) The name of the protocol Elasticsearch is reachable on. The options are: http or https. The default is http. However, if you specify a URL for hosts, the value of protocol is overridden by whatever scheme you specify in the URL.

proxy_disable

(boolean) If set to true, all proxy settings, including HTTP_PROXY and HTTPS_PROXY variables, are ignored.

Default: false

proxy_headers

(string) Additional headers to send to proxies during CONNECT requests.

proxy_url

(string) The URL of the proxy to use when connecting to the Elasticsearch servers. The value may be either a complete URL or a host[:port], in which case the http scheme is assumed. If a value is not specified through the configuration file then proxy environment variables are used. See the Go documentation for more information about the environment variables.

Authentication settings

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When sending data to a secured cluster through the elasticsearch output, Elastic Agent can use any of the following authentication methods:

Basic authentication credentials
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outputs:
  default:
    type: elasticsearch
    hosts: ["https://myEShost:9200"]
    username: "your-username"
    password: "your-password"
Setting Description

password

(string) The basic authentication password for connecting to Elasticsearch.

username

(string) The basic authentication username for connecting to Elasticsearch.

This user needs the privileges required to publish events to Elasticsearch.

Token-based (API key) authentication
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outputs:
  default:
    type: elasticsearch
    hosts: ["https://myEShost:9200"]
    api_key: "KnR6yE41RrSowb0kQ0HWoA"
Setting Description

api_key

(string) Instead of using a username and password, you can use API keys to secure communication with Elasticsearch. The value must be the ID of the API key and the API key joined by a colon: id:api_key.

Public Key Infrastructure (PKI) certificates
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outputs:
  default:
    type: elasticsearch
    hosts: ["https://myEShost:9200"]
    ssl.certificate: "/etc/pki/client/cert.pem"
    ssl.key: "/etc/pki/client/cert.key"

For a list of available settings, refer to SSL/TLS, specifically the settings under Table 1, “Common configuration options” and Table 2, “Client configuration options”.

Kerberos
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The following encryption types are supported:

  • aes128-cts-hmac-sha1-96
  • aes128-cts-hmac-sha256-128
  • aes256-cts-hmac-sha1-96
  • aes256-cts-hmac-sha384-192
  • des3-cbc-sha1-kd
  • rc4-hmac

Example output config with Kerberos password-based authentication:

outputs:
  default:
    type: elasticsearch
    hosts: ["http://my-elasticsearch.elastic.co:9200"]
    kerberos.auth_type: password
    kerberos.username: "elastic"
    kerberos.password: "changeme"
    kerberos.config_path: "/etc/krb5.conf"
    kerberos.realm: "ELASTIC.CO"

The service principal name for the Elasticsearch instance is constructed from these options. Based on this configuration, the name would be:

HTTP/my-elasticsearch.elastic.co@ELASTIC.CO

Setting Description

kerberos.auth_type

(string) The type of authentication to use with Kerberos KDC:

password
When specified, also set kerberos.username and kerberos.password.
keytab
When specified, also set kerberos.username and kerberos.keytab. The keytab must contain the keys of the selected principal, or authentication fails.

Default: password

kerberos.config_path

(string) Path to the krb5.conf. Elastic Agent uses this setting to find the Kerberos KDC to retrieve a ticket.

kerberos.enabled

(boolean) Enables or disables the Kerberos configuration.

Kerberos settings are disabled if either enabled is set to false or the kerberos section is missing.

kerberos.enable_krb5_fast

(boolean) If true, enables Kerberos FAST authentication. This may conflict with some Active Directory installations.

Default: false

kerberos.keytab

(string) If kerberos.auth_type is keytab, provide the path to the keytab of the selected principal.

kerberos.password

(string) If kerberos.auth_type is password, provide a password for the selected principal.

kerberos.realm

(string) Name of the realm where the output resides.

kerberos.username

(string) Name of the principal used to connect to the output.

Data parsing, filtering, and manipulation settings
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Settings used to parse, filter, and transform data.

Setting Description

escape_html

(boolean) Configures escaping of HTML in strings. Set to true to enable escaping.

Default: false

pipeline

(string) A format string value that specifies the ingest pipeline to write events to.

outputs:
  default:
    type: elasticsearchoutput.elasticsearch:
    hosts: ["http://localhost:9200"]
    pipeline: my_pipeline_id

You can set the ingest pipeline dynamically by using a format string to access any event field. For example, this configuration uses a custom field, fields.log_type, to set the pipeline for each event:

outputs:
  default:
    type: elasticsearch  hosts: ["http://localhost:9200"]
    pipeline: "%{[fields.log_type]}_pipeline"

With this configuration, all events with log_type: normal are sent to a pipeline named normal_pipeline, and all events with log_type: critical are sent to a pipeline named critical_pipeline.

To learn how to add custom fields to events, see the fields option.

See the pipelines setting for other ways to set the ingest pipeline dynamically.

pipelines

An array of pipeline selector rules. Each rule specifies the ingest pipeline to use for events that match the rule. During publishing, Elastic Agent uses the first matching rule in the array. Rules can contain conditionals, format string-based fields, and name mappings. If the pipelines setting is missing or no rule matches, the pipeline setting is used.

Rule settings:

pipeline
The pipeline format string to use. If this string contains field references, such as %{[fields.name]}, the fields must exist, or the rule fails.
mappings
A dictionary that takes the value returned by pipeline and maps it to a new name.
default
The default string value to use if mappings does not find a match.
when
A condition that must succeed in order to execute the current rule.

All the conditions supported by processors are also supported here.

The following example sends events to a specific pipeline based on whether the message field contains the specified string:

outputs:
  default:
    type: elasticsearch  hosts: ["http://localhost:9200"]
    pipelines:
      - pipeline: "warning_pipeline"
        when.contains:
          message: "WARN"
      - pipeline: "error_pipeline"
        when.contains:
          message: "ERR"

The following example sets the pipeline by taking the name returned by the pipeline format string and mapping it to a new name that’s used for the pipeline:

outputs:
  default:
    type: elasticsearch
    hosts: ["http://localhost:9200"]
    pipelines:
      - pipeline: "%{[fields.log_type]}"
        mappings:
          critical: "sev1_pipeline"
          normal: "sev2_pipeline"
        default: "sev3_pipeline"

With this configuration, all events with log_type: critical are sent to sev1_pipeline, all events with log_type: normal are sent to a sev2_pipeline, and all other events are sent to sev3_pipeline.

HTTP settings

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Settings that modify the HTTP requests sent to Elasticsearch.

Setting Description

headers

Custom HTTP headers to add to each request created by the Elasticsearch output.

Example:

outputs:
  default:
    type: elasticsearch
    headers:
      X-My-Header: Header contents

Specify multiple header values for the same header name by separating them with a comma.

parameters

Dictionary of HTTP parameters to pass within the URL with index operations.

path

(string) An HTTP path prefix that is prepended to the HTTP API calls. This is useful for the cases where Elasticsearch listens behind an HTTP reverse proxy that exports the API under a custom prefix.

Performance tuning settings

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Settings that may affect performance.

Setting Description

backoff.init

(string) The number of seconds to wait before trying to reconnect to Elasticsearch after a network error. After waiting backoff.init seconds, Elastic Agent tries to reconnect. If the attempt fails, the backoff timer is increased exponentially up to backoff.max. After a successful connection, the backoff timer is reset.

Default: 1s

backoff.max

(string) The maximum number of seconds to wait before attempting to connect to Elasticsearch after a network error.

Default: 60s

bulk_max_size

(int) The maximum number of events to bulk in a single Elasticsearch bulk API index request.

Events can be collected into batches. Elastic Agent will split batches larger than bulk_max_size into multiple batches.

Specifying a larger batch size can improve performance by lowering the overhead of sending events. However big batch sizes can also increase processing times, which might result in API errors, killed connections, timed-out publishing requests, and, ultimately, lower throughput.

Setting bulk_max_size to values less than or equal to 0 turns off the splitting of batches. When splitting is disabled, the queue decides on the number of events to be contained in a batch.

Default: 50

compression_level

(int) The gzip compression level. Set this value to 0 to disable compression. The compression level must be in the range of 1 (best speed) to 9 (best compression).

Increasing the compression level reduces network usage but increases CPU usage.

Default: 0

max_retries

(int) The number of times to retry publishing an event after a publishing failure. After the specified number of retries, the events are typically dropped.

Set max_retries to a value less than 0 to retry until all events are published.

Default: 3

timeout

(string) The HTTP request timeout in seconds for the Elasticsearch request.

Default: 90s

worker

(int) The number of workers per configured host publishing events to {output-type}. This is best used with load balancing mode enabled. Example: If you have two hosts and three workers, in total six workers are started (three for each host).

Default: 1