---
layout: docs
page_title: Store Consul gossip encryption key on Vault secrets backend
description: >-
  Configuring the Consul Helm chart to use a gossip encryption key stored in Vault.
---

# Store Consul gossip encryption key on Vault secrets backend

This topic describes how to configure the Consul Helm chart to use a gossip encryption key stored in Vault.

## Overview

Complete the steps outlined in the [Data Integration](/consul/docs/deploy/server/k8s/vault/data) section to use a gossip encryption key stored in Vault.

Complete the following steps once:
  1. Store the secret in Vault.
  1. Create a Vault policy that authorizes the desired level of access to the secret.
  
Repeat the following steps for each datacenter in the cluster:
  1. Create Vault Kubernetes auth roles that link the policy to each Consul on Kubernetes service account that requires access.
  1. Update the Consul on Kubernetes helm chart.

## Prerequisites
Prior to setting up the data integration between Vault and Consul on Kubernetes, you will need to have:  
1. Read and completed the steps in the [Systems Integration](/consul/docs/deploy/server/k8s/vault/backend) section of [Vault as a Secrets Backend](/consul/docs/deploy/server/k8s/vault).
2. Read the [Data Integration Overview](/consul/docs/deploy/server/k8s/vault/data) section of [Vault as a Secrets Backend](/consul/docs/deploy/server/k8s/vault).

## Store the Secret in Vault
First, generate and store the gossip key in Vault. You will only need to perform this action once:

```shell-session
$ vault kv put secret/consul/gossip key="$(consul keygen)"
```
## Create Vault policy

Next, create a policy that allows read access to this secret.

The path to the secret referenced in the `path` resource is the same value that you will configure in the  `global.gossipEncryption.secretName` Helm configuration (refer to [Update Consul on Kubernetes Helm chart](#update-consul-on-kubernetes-helm-chart)).

<CodeBlockConfig filename="gossip-policy.hcl">

```HCL
path "secret/data/consul/gossip" {
  capabilities = ["read"]
}
```

</CodeBlockConfig>

Apply the Vault policy by issuing the `vault policy write` CLI command:

```shell-session
$ vault policy write gossip-policy gossip-policy.hcl
```

## Create Vault Authorization Roles for Consul

Next, we will create Kubernetes auth roles for the Consul server and client:

```shell-session
$ vault write auth/kubernetes/role/consul-server \
    bound_service_account_names=<Consul server service account> \
    bound_service_account_namespaces=<Consul installation namespace> \
    policies=gossip-policy \
    ttl=1h
```

```shell-session
$ vault write auth/kubernetes/role/consul-client \
    bound_service_account_names=<Consul client service account> \
    bound_service_account_namespaces=<Consul installation namespace> \
    policies=gossip-policy \
    ttl=1h
```

To find out the service account names of the Consul server and client,
you can run the following `helm template` commands with your Consul on Kubernetes values file:

- Generate Consul server service account name
  ```shell-session
  $ helm template --release-name ${RELEASE_NAME} -s templates/server-serviceaccount.yaml hashicorp/consul -f values.yaml
  ```

- Generate Consul client service account name
  ```shell-session
  $ helm template --release-name ${RELEASE_NAME} -s templates/client-serviceaccount.yaml hashicorp/consul -f values.yaml
  ```

## Update Consul on Kubernetes Helm chart

Now that we've configured Vault, you can configure the Consul Helm chart to
use the gossip key in Vault:

<CodeBlockConfig filename="values.yaml">

```yaml
global:
  secretsBackend:
    vault:
      enabled: true
      consulServerRole: consul-server
      consulClientRole: consul-client
  gossipEncryption:
    secretName: secret/data/consul/gossip
    secretKey: key
```

</CodeBlockConfig>

Note that `global.gossipEncryption.secretName` is the path of the secret in Vault.
This should be the same path as the one you'd include in your Vault policy.
`global.gossipEncryption.secretKey` is the key inside the secret data. This should be the same
as the key we passed when we created the gossip secret in Vault.
