---
layout: docs
page_title: keyring Block in Agent Configuration
description: >-
  Configure keyring protection behavior in the `keyring` block of a Nomad agent configuration. Enable a keyring and configure a name. Learn how to configure keyring high availability (HA) and migrate keyrings.
---

# `keyring` Block in Agent Configuration

<Placement groups={['keyring']} />

This page provides reference information for configuring keyring protection
behavior in the `keyring` block of a Nomad agent configuration. Enable a keyring
and configure a name. Learn how to configure keyring high availability (HA) and
migrate keyrings.

The `keyring` block configures how the Nomad server protects the keyring used
for encrypting [variables][] and signing [workload identities][]. By default,
Nomad encrypts the key material with a unique key encryption key (KEK) that is
not shared between servers, and writes the wrapped key material to disk as
described in [Key Management][]. Nomad refers to this as `"aead"` (authenticated
encryption with associated data). Using the `keyring` configuration block, Nomad
servers can instead use an external key management system (KMS) or Vault transit
encryption. The encrypted key is stored on disk but is now protected against
offline attacks because the KEK is not present in the file.

All `keyring` blocks require a label for the KMS type. Each external KMS has its
own configuration options. The `keyring` block only applies to Nomad servers,
not Nomad clients.

```hcl
keyring [TYPE] {
  name   = "example"
  active = true
}
```

The default `keyring` configuration is as follows:

```hcl
keyring "aead" {
  active = true
}
```

## `keyring` Parameters

All `keyring` blocks support the following parameters.

- `name` `(string: "")` - A unique identifier for the `keyring` block, used to
  disambiguate when there are multiple blocks of the same type.

- `active` `(bool: false)` - Indicates which block to use for encrypting
  keys. For existing servers, changing which block is `active` only impacts new
  keys created by a [key rotation][]. Existing keys are encrypted with the
  previous `active` block, so those blocks should not be removed from the
  configuration until they have been garbage collected and the keys have been
  removed from the keystore. In Nomad Community Edition, only a single keyring
  can be `active` at a time.

## Migrating Keyrings

To migrate to a new keyring, add the new `keyring` block to the servers with
`active=true`, and restart the servers. The server starts using the new keyring
wrapper when the current key is rotated either periodically or via the [`nomad
operator root keyring rotate`][keyring_rotate_cmd] command.

Adding or removing a keyring requires restarting the Nomad server. You should
not remove a keyring until all keys it wraps have been garbage collected. You
can examine the contents of the `keystore` directory found in the Nomad server's
data directory and compare this against the output of [`nomad operator root
keyring list`][keyring_list_cmd].

## High Availability

<EnterpriseAlert product="nomad"/>

Keyring high availability provides the means to configure multiple active
`keyring` blocks, in order to have resilience against an outage of an external
KMS. When there are multiple `keyring` blocks with `active = true`, Nomad
Enterprise encrypts each key it creates in all the active KMS providers. On
startup, Nomad tries each KMS provider in order until it finds a provider that
can decrypt each key.

In this example high availability configuration, both `keyring` blocks use the
`"awskms"` provider, but each block uses a different KMS key in a different AWS
region.

```hcl
keyring "awskms" {
  active     = true
  name       = "kms-us-east-1"
  region     = "us-east-1"
  kms_key_id = "arn:aws:kms:us-east-1:000000000000:key/7d23633a-4464-11ef-a273-abd12example"
}

keyring "awskms" {
  active     = true
  name       = "kms-us-east-2"
  region     = "us-east-2"
  kms_key_id = "alias/nomad-keyring-us-east-2"
}
```

[variables]: /nomad/docs/concepts/variables
[workload identities]: /nomad/docs/concepts/workload-identity
[Key Management]: /nomad/docs/operations/key-management
[key rotation]: /nomad/docs/operations/key-management#key-rotation
[keyring_rotate_cmd]: /nomad/docs/commands/operator/root/keyring-rotate
[keyring_list_cmd]: /nomad/docs/commands/operator/root/keyring-list
