[[add-nomad-metadata]]
[role="xpack"]
=== Add Nomad metadata

++++
<titleabbrev>add_nomad_metadata</titleabbrev>
++++

experimental[]

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 runnning the allocation is located.

[source,yaml]
-------------------------------------------------------------------------------
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.

[source,hcl]
----
namespace "*" {
  policy = "read"
}
node {
  policy = "read"
}
agent {
  policy = "read"
}
----
`refresh_interval`:: (Optional) Interval used to updated 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, what can happen when
collecting logs. It defaults to 60 seconds.


You can decide if {beatname_uc} 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 {beatname_uc} is
collecting events from all the allocations in the cluster:

[source,yaml]
-------------------------------------------------------------------------------
processors:
  - add_nomad_metadata:
      scope: global
-------------------------------------------------------------------------------

==== Indexers and matchers

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

===== Indexers

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.
// Review examples below when new indexers are added with network information.

===== Matchers

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

===== `field_format`

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:

[source,yaml]
-------------------------------------------------------------------------------
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`

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:

[source,yaml]
-------------------------------------------------------------------------------
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']
-------------------------------------------------------------------------------

ifdef::has_nomad_logs_path_matcher[]
===== `logs_path`

Looks up allocation metadata using identifiers extracted from the log path stored in
the `log.file.path` field.

This matcher has an optional `logs_path` option with the base path of the
directory containing the logs for the local agent.

The default configuration is able to lookup the metadata using the allocation
UUID when the logs are collected under `/var/lib/nomad`.

For example the following configuration would use the allocation UUID when the logs
are collected from `/var/lib/NomadClient001/alloc/<alloc UUID>/alloc/logs/...`.

[source,yaml]
-------------------------------------------------------------------------------
processors:
- add_nomad_metadata:
    ...
    default_indexers.enabled: false
    default_matchers.enabled: false
    indexers:
      - allocation_uuid:
    matchers:
      - logs_path:
          logs_path: '/var/lib/NomadClient001'
-------------------------------------------------------------------------------
endif::has_nomad_logs_path_matcher[]
