---
layout: docs
page_title: Migrate Consul to Raft storage
description: >-
  Guide to migration of Consul storage to Raft. 
---

# Migrate Consul to Raft storage

This procedure assumes you have a Vault cluster deployed in a Kubernetes environment configured with Consul storage.  The storage migration can occur while leaving the Consul cluster intact.  A single change to the Consul cluster is a lock file written by Vault during the migration.

This guide uses basic examples and default Vault configurations.  It is for illustrative purposes, and adaption to specific configurations relevant to your environment is still required.

<Warning title="Back up data">

Always back up your data before attempting migration! Although this is an offline operation and the risk is low, it is advisable to take a recent snapshot from your Consul cluster before proceeding.

</Warning>

## Overview

This guide uses an intermediate Helm configuration to introduce an init container that will perform the storage migration, and then start a single Vault server using the Raft storage backend to verify the results.  Then update the Helm configuration to remove the init container and start Vault replicas.

### Vault and Kubernetes setup

Consider the following `vault status` output and Helm Chart values for Vault:

<CodeBlockConfig hideClipboard>

```plaintext
Key             Value
---             -----
Seal Type       shamir
Initialized     true
Sealed          false
Total Shares    1
Threshold       1
Version         1.14.8+ent
Build Date      2023-12-05T01:49:39Z
Storage Type    consul
Cluster Name    vault-cluster-68870bf8
Cluster ID      cd18c692-f2e3-77a5-fba3-28f06f41f375
HA Enabled      true
HA Cluster      https://vault-0.vault-internal:8201
HA Mode         active
Active Since    2024-04-10T02:45:33.367042122Z
Last WAL        52
```

</CodeBlockConfig>

Helm chart values:

<CodeBlockConfig hideClipboard>

```plaintext
global:
  enabled: false

server:
  enabled: true
  image:
    repository: hashicorp/vault-enterprise
    tag: 1.14.8-ent
  enterpriseLicense:
    secretName: vault-license
    secretKey: vault.hclic
  ha:
    enabled: true
    replicas: 3
    config: |
      ui = true
      service_registration "kubernetes" {}

      listener "tcp" {
        address = ":8200"
        cluster_address = ":8201"
        tls_disable = 1
      }

      storage "consul" {
        path = "vault"
        address = "http://HOST_IP:8500"
      }
```

</CodeBlockConfig>

### Migration procedure

1. Uninstall Vault via Helm.

  ```shell-session
  $ helm uninstall vault
  ```

  Deployed `StatefulSets` cannot have certain attributes modified after their initial deployment.  Therefore, the `StatefulSet` deployment must be entirely replaced.

 Vault servers using Consul storage are by default stateless. Unless explicitly configured, the Vault server `StatefulSet` does not create any Persistent Volume Claims (PVC) or other artifacts.  Vault's index holds its state, which is entirely stored in the Consul server `StatefulSet`'s persistent volumes.

  <Warning title='Caution'>

  It is strongly advised to review your Vault deployment configurations and take appropriate backups for any stateful information managed via Helm or other orchestration platforms.

  </Warning>

1. Create a `ConfigMap` containing the Storage Migration configuration.

  ```shell-session
  $ cat > vault-storage-migration-configmap.yml <<EOF
  apiVersion: v1
  kind: ConfigMap
  metadata:
    labels:
      app.kubernetes.io/instance: vault
      app.kubernetes.io/name: vault
    name: storage-migration
    namespace: default
  data:
    migrate.hcl: |-
      storage_source "consul" {
        address = "http://consul-server.default.svc.cluster.local:8500"
        path = "vault/"
      }

      storage_destination "raft" {
        path = "/vault/data"
      }

      cluster_addr = "https://vault-0.vault-internal:8201" 
  EOF
  ```
  
  Often your Vault server should communicate to Consul via a Consul client agent.  This example uses the service endpoint for a Consul server deployed in Kubernetes, although it can work for a Consul server cluster deployed outside of Kubernetes as well.

1. Apply the `ConfigMap`.

  ```shell-session
  $ kubectl create -f vault-storage-migration-configmap.yml
  ```

1. Install Vault via Helm deployment with Raft Migration storage configuration.

  ```shell-session
  $ cat > vault-migration-values.yml <<EOF
  global:
    enabled: false

  server:
    enabled: true
    image:
      repository: hashicorp/vault-enterprise
      tag: 1.14.8-ent
    enterpriseLicense:
      secretName: vault-license
      secretKey: vault.hclic
    extraInitContainers:
      - name: vault-storage-migration
        image: hashicorp/vault-enterprise:1.14.8-ent
        command:
          - "/bin/sh"
          - "-ec"
        args:
          - "/bin/vault operator migrate -config /vault/storage-migration/migrate.hcl"
        volumeMounts:
          - name: storage-migration
            mountPath: "/vault/storage-migration"
          - name: data
            mountPath: "/vault/data"
    volumeMounts:
      - name: storage-migration
        mountPath: "/vault/storage-migration"
    volumes:
      - name: storage-migration
        configMap:
          name: storage-migration
    dataStorage:
      enabled: true
      size: "1Gi"
    ha:
      enabled: true
      replicas: 1
      raft:
        enabled: true
        config: |
          ui = true
          service_registration "kubernetes" {}

          listener "tcp" {
            address = ":8200"
            cluster_address = ":8201"
            tls_disable = 1
          }

          storage "raft" {
            path = "/vault/data"
            retry_join {
              auto_join_scheme = "http"
              auto_join = "provider=k8s"
            }
          }
  EOF
  ```

  **Configuration notes**
    - `storage “raft”` configuration to specify the path for the Raft DB (`/vault/data` by default), and any `retry_join` parameters in your original configuration.
      - This example uses `auto_join` to automatically find Raft peers via the Kubernetes API.  See the [`retry_join`](/vault/docs/configuration/storage/raft#retry_join-stanza) for more information.
    - `dataStorage` configuration in the Helm override values, to specify the parameters of the PVCs the Vault `StatefulSet` will create.
    - `extraInitContainers` will start an init container mounting the storage migration ConfigMap and `data` volume, which it will then use to execute the storage migration.  
    - `replicas: 1`
      - This setting is temporary for the purposes of the migration.  A new Vault `StatefulSet` with one replica to confirm the init container completed the migration and unseal Vault using the new storage backend.

1. Apply this configuration.

  ```shell-session
  $ helm install vault hashicorp/vault -f vault-migration-values.yml
  ```
  
1. Review the migration logs.
  
  ```shell-session
  $ kubectl logs vault-0 -c vault-server-migration
  ```
  
1. Unseal Vault.

  ```shell-session
  $ kubectl exec -it vault-0 -- vault operator unseal
  Key                     Value
  ---                     -----
  Seal Type               shamir
  Initialized             true
  Sealed                  false
  Total Shares            1
  Threshold               1
  Version                 1.14.8+ent
  Build Date              2023-12-05T01:49:39Z
  Storage Type            raft
  Cluster Name            vault-cluster-68870bf8
  Cluster ID              cd18c692-f2e3-77a5-fba3-28f06f41f375
  HA Enabled              true
  HA Cluster              https://vault-0.vault-internal:8201
  HA Mode                 active
  Active Since            2024-04-10T04:20:23.707098402Z
  Raft Committed Index    157
  Raft Applied Index      157
  Last WAL                55
  ```

1. Update Vault Helm deployment with Raft storage configuration.

  ```shell-session
  $ cat > vault-raft-values.yml <<EOF
  global:
    enabled: false
  server:
    enabled: true
    image:
      repository: hashicorp/vault-enterprise
      tag: 1.14.8-ent
    enterpriseLicense:
      secretName: vault-license
      secretKey: vault.hclic
    dataStorage:
      enabled: true
      size: "1Gi"
    ha:
      enabled: true
      replicas: 5
      raft:
        enabled: true
        config: |
          ui = true
          service_registration "kubernetes" {}

          listener "tcp" {
            address = ":8200"
            cluster_address = ":8201"
            tls_disable = 1
          }

          storage "raft" {
            path = "/vault/data"
            retry_join {
              auto_join_scheme = "http"
              auto_join = "provider=k8s"
            }
          }
  EOF
  ```
  **Configuration notes**
    - `replicas: 5`
      - Upgrade the Helm deployment in place using the final Raft storage configuration, removing the `extraInitContainer` and storage migration `ConfigMap`, and increasing the number of replicas.  The `retry_join` parameters used by the new Vault server replicas to automatically join the cluster.

1. Apply the configuration.

  ```shell-session
  $ helm upgrade vault hashicorp/vault -f vault-raft-values.yml
  ```
  
1. Unseal Vault.

  ```shell-session
  $ for i in {1..4} ; do kubectl exec -it vault-0 -- vault operator unseal ; done
  ```

1. Confirm the Raft peers have formed a quorum.

  ```shell-session
  $ kubectl exec -it vault-0 -- vault operator raft list-peers

  Node                                    Address                        State       Voter
  ----                                    -------                        -----       -----
  24c166d8-a8bb-3ac7-f8a0-12bd066a34bb    vault-0.vault-internal:8201    leader      true
  626434d1-170b-575a-2a04-af4f2e90820b    vault-1.vault-internal:8201    follower    true
  1dfbba31-9b5b-2d16-18ce-bfa7b6c0ead6    vault-2.vault-internal:8201    follower    true
  3f333082-1a64-7559-0142-e4f1658a28f3    vault-3.vault-internal:8201    follower    true
  9ca5a15e-3ddc-d132-0b46-5b895f3828dc    vault-4.vault-internal:8201    follower    true
  ```
  
## Rollback procedure

To revert to the original configuration, you'll just need to delete the Helm deployment, and re-deploy it using the override values specifying your Consul storage configuration.

Note that the Vault Helm Chart's default configuration using Raft storage will retain any PVCs created.  Vault does not use these while configured with Consul storage.  You will need to remove the PVCs before re-attempting the migration.

1. Uninstall Vault via Helm.

  ```shell-session
  $ helm uninstall vault
  ```

1. Install Vault via Helm with old Consul storage configuration.

  ```shell-session
  $ `helm install vault hashicorp/vault -f vault-consul-values.yml
  ```
  
1. Unseal Vault and confirm the storage has reverted to Consul.

  <CodeBlockConfig highlight="11">

  ```she-session
  $ kubectl exec -it vault-0 -- vault status
  Key             Value
  ---             -----
  Seal Type       shamir
  Initialized     true
  Sealed          false
  Total Shares    1
  Threshold       1
  Version         1.14.8+ent
  Build Date      2023-12-05T01:49:39Z
  Storage Type    consul
  Cluster Name    vault-cluster-68870bf8
  Cluster ID      cd18c692-f2e3-77a5-fba3-28f06f41f375
  HA Enabled      true
  HA Cluster      https://vault-0.vault-internal:8201
  HA Mode         active
  Active Since    2024-04-10T04:44:12.516016652Z
  Last WAL        54
  ```

  </CodeBlockConfig>

## References

- [Vault operator migrate command](/vault/docs/commands/operator/migrate)
- [Helm Chart configuration](/vault/docs/platform/k8s/helm/configuration)
- [Vault on Kubernetes deployment guide](/vault/tutorials/kubernetes/kubernetes-raft-deployment-guide)
- [Vault Helm Chart configuration](https://github.com/hashicorp/vault-helm)
- [kubectl commands](https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands)
- [Kubernetes storage volumes](https://kubernetes.io/docs/concepts/storage/volumes/)
- [Create a Pod that has an Init Container](https://kubernetes.io/docs/tasks/configure-pod-container/configure-pod-initialization/#create-a-pod-that-has-an-init-container)
- [Helm docs](https://helm.sh/docs/)
