openstack-charmers/charm-interface-vault-kv

Vault interface for simple KV secrets management

Overview

This interface handles the communication with the vault charm using the vault-kv interface type.

Vault will enable simple KV based secrets backends with AppRole based authentication and policies to allow consuming charms to store and retrieve secrets in Vault.

Access to the backend will be limited to the network address binding of of the relation endpoint name and ownership of a secret_id which the consuming application must retrieve using a one-shot token out-of-band from Juju.

Usage

Requires

The interface layer will set the following reactive states, as appropriate:

• {relation_name}.connected The relation is established and ready for the local charm to make a request for access to a secrets backend using the request_secret_backend method.

• {relation_name}.available When vault has created the backend and an associated AppRole to allow the local charm to store and retrieve secrets in vault - the vault_url and unit_role_id properties will be set.

For example:

from charms.reactive.flags import endpoint_from_flag

 @when('secrets-storage.connected')
 def ss_connected():
 	secrets = endpoint_from_flag('secrets-storage.connected')
 	secrets.request_secret_backend('charm-vaultlocker', isolated=True)


 @when('secrets-storage.available')
 def ss_ready_for_use():
 	secrets = endpoint_from_flag('secrets-storage.connected')
 	configure_my_local_service(
 		vault_url=secrets.vault_url,
 		role_id=secrets.unit_role_id,
        secret_id=vault.get_response(secrets.unit_token),
 		backend='charm-vaultlocker',
 	)

Interface Schema Details

• Initiates the kv-store requesting a secrets backend by sending:

  • str - secret_backend

    Note that the backend name must be prefixed with 'charm-' otherwise the vault charm will skip creation of the secrets backend and associated access.

  • str - unit_name

    formatted by the requirer as '$model-uuid:$unit-name' using a '-' to delimit between the model-uuid and the juju unit-name

  • str - access_address

    ip address used to gain access this kv-store, will be associated as a CIDR with netmask /32 with the authorized vault token when isolated

  • str - hostname

    Creates an approle with a policy associated with this unit's hostname.

  • bool - isolated (defaults: True )

    • True - sets the policy on the secret to SECRET_BACKEND_HCL
    • False - sets the policy on the secret to SECRET_BACKEND_SHARED_HCL