Juju Charm - Vault secrets managment
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The vault charm deploys Vault, a tool for securely managing secrets used in modern computing (e.g. passwords, certificates, API keys). Charmed OpenStack employs Vault to handle TLS certificates, allowing for a centrally managed solution for the encryption of API services across the cloud. Vault is also commonly used to implement Encryption at Rest on Charmed OpenStack.

The charm installs Vault from a snap.

Important: Vault is a requirement for the OVN charms.



This section covers common and/or important configuration options. See file config.yaml for the full list of options, along with their descriptions and default values. See the Juju documentation for details on configuring applications.


The channel option sets the snap channel to use for deployment (e.g. 'latest/edge'). The default value is 'latest/stable'.


Important: Some steps must be performed after deployment. Section 'Post-deployment tasks' covers this.

Vault is often containerised. Here a single unit is deployed to a new container on machine '1':

juju deploy --to lxd:1 vault

Note: When Vault is deployed to metal or to a KVM guest the charm will enable mlock (memory locking) to prevent secrets from being saved to disk via page swapping. The mlock feature is not available to containers.

Now connect the vault application to an existing database. This can be the cloud's database or a separate, dedicated database.

Some database applications are influenced by the series. Prior to focal percona-cluster is used, otherwise it is replaced by mysql-innodb-cluster. The postgresql application can also be used.

For percona-cluster:

juju add-relation vault:shared-db percona-cluster:shared-db

For mysql-innodb-cluster:

juju deploy mysql-router vault-mysql-router
juju add-relation vault-mysql-router:db-router mysql-innodb-cluster:db-router
juju add-relation vault-mysql-router:shared-db vault:shared-db

For postgresql:

juju add-relation vault:db postgresql:db

Note: For PostgreSQL, its version and the underlying machine series must be compatible (e.g. 9.5/xenial or 10/bionic). The postgresql charm's configuration option version is used to select a version at deploy time.


Communication with the Vault REST API can be encrypted with TLS. This is configured with the following charm configuration options:

  • ssl-ca
  • ssl-cert
  • ssl-chain
  • ssl-key

Note: The process of encrypting the Vault API is separate from that of using Vault to manage the encryption of OpenStack API services. See Managing TLS certificates in the OpenStack Charms Deployment Guide for details.

Post-deployment tasks

Once the application is deployed the following tasks must be performed:

  • Vault initialisation
  • Unsealing of Vault
  • Charm authorisation

Vault itself will be needed as a client to perform these tasks.

Vault client

Vault is needed as a client in order to manage the Vault deployment. Install it on the host where the Juju client resides:

sudo snap install vault

Initialise Vault

Identify the vault unit by setting the VAULT_ADDR environment variable based on the IP address of the unit. This can be discovered from juju status output (column 'Public address'). Here we'll use '':

export VAULT_ADDR=""

Initialise Vault by specifying the number of unseal keys that should get generated as well as the number of unseal keys that are needed in order to complete the unseal process. Below we will specify five and three, respectively:

vault operator init -key-shares=5 -key-threshold=3

Sample output:

Unseal Key 1: XONSc5Ku8HJu+ix/zbzWhMvDTiPpwWX0W1X/e/J1Xixv
Unseal Key 2: J/fQCPvDeMFJT3WprfPy17gwvyPxcvf+GV751fTHUoN/
Unseal Key 3: +bRfX5HMISegsODqNZxvNcupQp/kYQuhsQ2XA+GamjY4
Unseal Key 4: FMRTPJwzykgXFQOl2XTupw2lfgLOXbbIep9wgi9jQ2ls
Unseal Key 5: 7rrxiIVQQWbDTJPMsqrZDKftD6JxJi6vFOlyC0KSabDB

Initial Root Token: s.ezlJjFw8ZDZO6KbkAkm605Qv

Vault initialized with 5 key shares and a key threshold of 3. Please securely
distribute the key shares printed above. When the Vault is re-sealed,
restarted, or stopped, you must supply at least 3 of these keys to unseal it
before it can start servicing requests.

Vault does not store the generated master key. Without at least 3 key to
reconstruct the master key, Vault will remain permanently sealed!

It is possible to generate new unseal keys, provided you have a quorum of
existing unseal keys shares. See "vault operator rekey" for more information.

Besides displaying the five unseal keys the output also includes an "initial root token". This token is used to access the Vault API.

Warning: It is not possible to unseal Vault without the unseal keys, nor is it possible to manage Vault without the initial root token. Store this information in a safe place immediately.

Unseal Vault

Unseal the vault unit using the requisite number of unique keys (three in this example):

vault operator unseal XONSc5Ku8HJu+ix/zbzWhMvDTiPpwWX0W1X/e/J1Xixv
vault operator unseal FMRTPJwzykgXFQOl2XTupw2lfgLOXbbIep9wgi9jQ2ls
vault operator unseal 7rrxiIVQQWbDTJPMsqrZDKftD6JxJi6vFOlyC0KSabDB

In an HA environment repeat the unseal process for each unit. Prior to unsealing a unit change the value of the VAULT_ADDR variable so that it points to that unit.

Note: Maintenance work on the cloud may require vault units to be paused and later resumed. A resumed vault unit will be sealed and will therefore require unsealing. See Managing power events in the OpenStack Charms Deployment Guide for details.

Proceed to the next step once all units have been unsealed.

Authorise the vault charm

The vault charm must be authorised to access the Vault deployment in order to create storage backends (for secrets) and roles (to allow other applications to access Vault for encryption key storage).

Generate a root token with a limited lifetime (10 minutes here) using the initial root token:

export VAULT_TOKEN=s.ezlJjFw8ZDZO6KbkAkm605Qv
vault token create -ttl=10m

Sample output:

Key                  Value
---                  -----
token                s.QMhaOED3UGQ4MeH3fmGOpNED
token_accessor       nApB972Dp2lnTTIF5VXQqnnb
token_duration       10m
token_renewable      true
token_policies       ["root"]
identity_policies    []
policies             ["root"]

This temporary token ('token') is then used to authorise the charm:

juju run-action --wait vault/leader authorize-charm token=s.QMhaOED3UGQ4MeH3fmGOpNED

After the action completes execution, the vault unit(s) will become active and any pending requests for secrets storage will be processed for consuming applications.

Here is sample status output for an unsealed three-unit Vault cluster:

vault/0*                 active    idle   0/lxd/1      8200/tcp  Unit is ready (active: false, mlock: disabled)
  vault-hacluster/0*     active    idle                  Unit is ready and clustered
  vault-mysql-router/0*  active    idle                  Unit is ready
vault/1                  active    idle   1/lxd/1      8200/tcp  Unit is ready (active: true, mlock: disabled)
  vault-hacluster/2      active    idle                  Unit is ready and clustered
  vault-mysql-router/2   active    idle                  Unit is ready
vault/2                  active    idle   2/lxd/1      8200/tcp  Unit is ready (active: false, mlock: disabled)
  vault-hacluster/1      active    idle                  Unit is ready and clustered
  vault-mysql-router/1   active    idle                  Unit is ready

Now that the post-deployment steps have been completed you will most likely want to add a CA certificate to Vault. See Managing TLS certificates in the OpenStack Charms Deployment Guide for details.


This section lists Juju actions supported by the charm. Actions allow specific operations to be performed on a per-unit basis.

  • authorize-charm
  • disable-pki
  • generate-root-ca
  • get-csr
  • get-root-ca
  • pause
  • refresh-secrets
  • reissue-certificates
  • resume
  • upload-signed-csr
  • reload
  • restart

To display action descriptions run juju actions --schema vault. If the charm is not deployed then see file actions.yaml.

High availability

When more than one unit is deployed with the hacluster application the charm will bring up an HA active/active cluster.

There are two mutually exclusive high availability options: using virtual IP(s) or DNS. In both cases the hacluster subordinate charm is used to provide the Corosync and Pacemaker backend HA functionality.

In addition, HA Vault will require the etcd and easyrsa applications.

See Infrastructure high availability in the OpenStack Charms Deployment Guide for details.


The OpenStack Charms project maintains two documentation guides:


Please report bugs on Launchpad.