[Discuss] Add agent.group and host.group field

[adrianchen-es]

Summary

Add agent.group,host.group field to facilitate searching for a group of agents/hosts based on a user-configurable arbitrary grouping.

Motivation:
These arbitrary user-configurable fields will improve the search and analysis experience for Security and Observability.

Security:

• Find alerts and events based on agent.group or host.group
• Create custom alerts to target a group of hosts

Observability:

• Find alerts and metrtics based on agent.group or host.group
• Create custom alerts to target a group of hosts

ABAC:

• Grant access to a user group based on agent.group or host.group

Once added as an ECS field, it should be included in the Elastic Security fields.

Currently, users create a custom field to facilitate this type of grouping.

Detailed Design:
The agent.group or host.group field could treated like data_stream.namespace but used to group agents or hosts instead of data.

• Field names

• agent.group
• host.group

• Example values for the fields
  -APP-A_PROD
  -APP-A_DEV
  -APP-B_DEV

• Suggested appropriate datatypes
  Type: keyword

• Any example events that map to the proposed use case(s)

Event A from host001 in the APP-A_PROD group

{
  "_index": ".ds-metrics-system.process.summary-default-2024.05.03-000042",
  "_id": "FVwmT7YoA8jJjD7HAAABj0PMPl0",
  "_version": 1,
  "_score": 0,
  "_source": {
    "@timestamp": "2024-05-04T13:30:09.885Z",
    "agent": {
      "ephemeral_id": "85174b4b-4415-46c4-89ce-160e27a56bc5",
      "id": "a8435320-1d60-49f7-b1e7-25ed5d5eb59c",
      "name": "host001",
      "group": "APP-A_PROD",
      "type": "metricbeat",
      "version": "8.13.3"
    },
    "data_stream": {
      "dataset": "system.process.summary",
      "namespace": "default",
      "type": "metrics"
    },
    "ecs": {
      "version": "8.0.0"
    },
    "elastic_agent": {
      "id": "a8435320-1d60-49f7-b1e7-25ed5d5eb59c",
      "snapshot": false,
      "version": "8.13.3"
    },
    "event": {
      "agent_id_status": "verified",
      "dataset": "system.process.summary",
      "duration": 16289873,
      "ingested": "2024-05-04T13:30:10Z",
      "module": "system"
    },
    "host": {
      "architecture": "x86_64",
      "containerized": false,
      "hostname": "host001",
      "group": "APP-A_PROD",
      "id": "0ba1be1199e74165a458a3bb0f65fb8f",
      "ip": [
      ],
      "mac": [
      ],
      "name": "host001",
      "os": {
        "codename": "Plow",
        "family": "redhat",
        "kernel": "5.14.0-427.13.1.el9_4.x86_64",
        "name": "Red Hat Enterprise Linux",
        "platform": "rhel",
        "type": "linux",
        "version": "9.0 (Plow)"
      }
    },
    "metricset": {
      "name": "process_summary",
      "period": 10000
    },
    "service": {
      "type": "system"
    },
    "system": {
      "process": {
        "summary": {
          "disk_sleep": 1,
          "idle": 96,
          "sleeping": 272,
          "threads": {
            "blocked": 14,
            "running": 1
          },
          "total": 370,
          "zombie": 1
        }
      }
    }
  }
}

Event B from host002 in the APP-A_PROD group

{
  "_index": ".ds-metrics-system.process.summary-default-2024.05.03-000042",
  "_id": "FVwmT7YoA8jJjD7HAAABj0PMPl0",
  "_version": 1,
  "_score": 0,
  "_source": {
    "@timestamp": "2024-05-04T13:30:09.885Z",
    "agent": {
      "ephemeral_id": "85174b4b-4415-46c4-89ce-160e27a56bc5",
      "id": "a8435320-1d60-49f7-b1e7-25ed5d5eb59c",
      "name": "host002",
      "group": "APP-A_PROD",
      "type": "metricbeat",
      "version": "8.13.3"
    },
    "data_stream": {
      "dataset": "system.process.summary",
      "namespace": "default",
      "type": "metrics"
    },
    "ecs": {
      "version": "8.0.0"
    },
    "elastic_agent": {
      "id": "a8435320-1d60-49f7-b1e7-25ed5d5eb59c",
      "snapshot": false,
      "version": "8.13.3"
    },
    "event": {
      "agent_id_status": "verified",
      "dataset": "system.process.summary",
      "duration": 16289873,
      "ingested": "2024-05-04T13:30:10Z",
      "module": "system"
    },
    "host": {
      "architecture": "x86_64",
      "containerized": false,
      "hostname": "host002",
      "group": "APP-A_PROD",
      "id": "0ba1be1199e74165a458a3bb0f65fb8f",
      "ip": [
      ],
      "mac": [
      ],
      "name": "host002",
      "os": {
        "codename": "Plow",
        "family": "redhat",
        "kernel": "5.14.0-427.13.1.el9_4.x86_64",
        "name": "Red Hat Enterprise Linux",
        "platform": "rhel",
        "type": "linux",
        "version": "9.0 (Plow)"
      }
    },
    "metricset": {
      "name": "process_summary",
      "period": 10000
    },
    "service": {
      "type": "system"
    },
    "system": {
      "process": {
        "summary": {
          "disk_sleep": 1,
          "idle": 96,
          "sleeping": 272,
          "threads": {
            "blocked": 14,
            "running": 1
          },
          "total": 370,
          "zombie": 1
        }
      }
    }
  }
}