Add Nomad metadata

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This functionality is in technical preview and may be changed or removed in a future release. Elastic will work to fix any issues, but features in technical preview are not subject to the support SLA of official GA features.

The add_nomad_metadata processor adds fields with relevant metadata for applications deployed in Nomad.

Each event is annotated with the following information:

  • Allocation name, identifier and status.
  • Job name and type.
  • Namespace where the job is deployed.
  • Datacenter and region where the agent running the allocation is located.
processors:
  - add_nomad_metadata: ~

It has the following settings to configure the connection:

address
(Optional) The URL of the agent API used to request the metadata. It uses http://127.0.0.1:4646 by default.
namespace
(Optional) Namespace to watch. If set, only events for allocations in this namespace will be annotated.
region
(Optional) Region to watch. If set, only events for allocations in this region will be annotated.
secret_id
(Optional) SecretID to use when connecting with the agent API. This is an example ACL policy to apply to the token.
namespace "*" {
  policy = "read"
}
node {
  policy = "read"
}
agent {
  policy = "read"
}
refresh_interval
(Optional) Interval used to update the cached metadata. It defaults to 30 seconds.
cleanup_timeout
(Optional) After an allocation has been removed, time to wait before cleaning up their associated resources. This is useful if you expect to receive events after an allocation has been removed, which can happen when collecting logs. It defaults to 60 seconds.

You can decide if Functionbeat should annotate events related to allocations in local node or on the whole cluster configuring the scope with the following settings:

scope
(Optional) Scope of the resources to watch. It can be node to get metadata only for the allocations in a single agent, or global, to get metadata for allocations running on any agent. It defaults to node.
node
(Optional) When using scope: node, use node to specify the name of the local node if it cannot be discovered automatically.

For example the following configuration could be used if Functionbeat is collecting events from all the allocations in the cluster:

processors:
  - add_nomad_metadata:
      scope: global

Indexers and matchers

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Indexers and matchers are used to correlate fields in events with actual metadata. Functionbeat uses this information to know what metadata to include in each event.

Indexers

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Indexers use allocation metadata to create unique identifiers for each one of the pods.

Avaliable indexers are: allocation_name:: Identifies allocations by its name and namespace (as <namespace>/<name>) allocation_uuid:: Identifies allocations by its unique identifier.

Matchers

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Matchers are used to construct the lookup keys that match with the identifiers created by indexes.

field_format

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Looks up allocation metadata using a key created with a string format that can include event fields.

This matcher has an option format to define the string format. This string format can contain placeholders for any field in the event.

For example, the following configuration uses the allocation_name indexer to identify the allocation metadata by its name and namespace, and uses custom fields existing in the event as match keys:

processors:
- add_nomad_metadata:
    ...
    default_indexers.enabled: false
    default_matchers.enabled: false
    indexers:
      - allocation_name:
    matchers:
      - field_format:
          format: '%{[labels.nomad_namespace]}/%{[fields.nomad_alloc_name]}'

fields

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Looks up allocation metadata using as key the value of some specific fields. When multiple fields are defined, the first one included in the event is used.

This matcher has an option lookup_fields to define the fields whose value will be used for lookup.

For example, the following configuration uses the allocation_uuid indexer to identify allocations, and defines a matcher that uses some fields where the allocation UUID can be found for lookup, the first it finds in the event:

processors:
- add_nomad_metadata:
    ...
    default_indexers.enabled: false
    default_matchers.enabled: false
    indexers:
      - allocation_uuid:
    matchers:
      - fields:
          lookup_fields: ['host.name', 'fields.nomad_alloc_uuid']