ElasticSearch / OpenSearch plugin

The elasticsearch plugin inserts Alumet measurements into ElasticSearch or OpenSearch (the API that we use is identical in both projects).

Requirements

Write access to an ElasticSearch or Opensearch instance

Configuration

Here is an example of how to configure this plugin. Put the following in the configuration file of the Alumet agent (usually alumet-config.toml).

[plugins.elasticsearch]
# The url of the database instance.
server_url = "http://localhost:9200"
# Controls the use of certificate validation and hostname verification.
# You should think very carefully before you use this!
allow_insecure = false
# The prefix added to each index (format `{index_prefix}-{metric_name}`).
index_prefix = "alumet"
# Controls the use of an optional suffix for each index (format `{index_prefix}-{metric_name}-{metric_unit_unique_name}`).
metric_unit_as_index_suffix = false

[plugins.elasticsearch.auth.basic]
# Authentication Settings: Credentials in the config (Basic auth)
user = "TODO"
password = "TODO"

Authentication

Multiple auth schemes are supported.

Basic auth

You can give the username and password in the config:

[plugins.elasticsearch.auth.basic]
# Authentication Settings: Credentials in the config (Basic auth)
user = "TODO"
password = "TODO"

Or ask the plugin to read them from a file, which must contain the username and password separated by a colon (:):

[plugins.elasticsearch.auth.basic_file]
# Authentication Settings: Credentials in another file (Basic auth)
file = "basic_auth.txt"

Example file basic_auth.txt:

user:password

API key auth

[plugins.elasticsearch.auth.api_key]
# Authentication Settings: Credentials in the config (API key auth)
key = "your key here"

Bearer auth

[plugins.elasticsearch.auth.bearer]
# Authentication Settings: Credentials in the config (Bearer auth)
token = "your token here"

The elasticsearch plugin inserts Alumet measurements by generating an index in the database for each metric in format {index_prefix}-{metric_name} or {index_prefix}-{metric_name}-{metric_unit_unique_name} if configured so.

See index basics.

Output Example

Here is the json representation for a MeasurementPoint for the metric kernel_cpu_time inside the database:

{
  "_index": "alumet-kernel_cpu_time",
  "_id": "gmyozJgBNhZm2PkkYwJ8",
  "_version": 1,
  "_score": 1,
  "fields": {
    "cpu_state": [
      "user"
    ],
    "consumer_id": [
      ""
    ],
    "@timestamp": [
      "2025-01-01T12:00:00.000000000Z"
    ],
    "cpu_state.keyword": [
      "user"
    ],
    "resource_id": [
      ""
    ],
    "resource_kind": [
      "local_machine"
    ],
    "consumer_kind": [
      "local_machine"
    ],
    "value": [
      1420
    ]
  }
}

See MeasurementPoint for more details.

ALUMET user guide