Juju Charm - Keystone
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
Zuul b900f831a5 Merge "Review README" 6 days ago
actions Fix lint errors E741 and E741 6 months ago
charmhelpers Batch update to land Ubuntu Groovy support into the charms 1 month ago
files Sync charm/ceph helpers, tox, and requirements 1 year ago
hooks Make Fernet key distribution more robust 2 weeks ago
lib Update README.md and gitkeep consistancy 1 year ago
scripts Make Fernet key distribution more robust 2 weeks ago
templates Make catalog-cache-expiration configurable 2 months ago
tests Add focal-victoria to the test gate 2 months ago
unit_tests Make Fernet key distribution more robust 2 weeks ago
.gitignore endpoint notification: provide full endpoint 9 months ago
.gitreview OpenDev Migration Patch 1 year ago
.project Merge ssl-everywhere branch (may break stuff) 6 years ago
.pydevproject endpoint notification: provide full endpoint 9 months ago
.stestr.conf Configure stestr directly 1 year ago
.zuul.yaml Switch to Ussuri jobs 1 year ago
LICENSE Re-license charm as Apache-2.0 4 years ago
Makefile Resync charmhelpers 9 months ago
README.md Review README 1 week ago
actions.yaml Add security checklist to Keystone 1 year ago
charm-helpers-hooks.yaml Sync charm/ceph helpers, tox, and requirements 1 year ago
config.yaml Review README 1 week ago
copyright Re-license charm as Apache-2.0 4 years ago
hardening.yaml Add hardening support 4 years ago
icon.svg Updated icon 3 years ago
metadata.yaml Updates for 20.08 cycle start for groovy and libs 4 months ago
requirements.txt Do not leak credentials on leader-set failure 2 months ago
setup.cfg Add Python 3 Train unit tests 1 year ago
test-requirements.txt Sync libraries & common files prior to freeze 2 months ago
tox.ini Do not leak credentials on leader-set failure 2 months ago



The keystone charm deploys Keystone, the core OpenStack service that provides API client authentication, service discovery, and distributed multi-tenant authorization. The charm works alongside other Juju-deployed OpenStack services.



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 openstack-origin option states the software sources. A common value is an OpenStack UCA release (e.g. ‘cloud:bionic-ussuri’ or ‘cloud:focal-victoria’). See Ubuntu Cloud Archive. The underlying host’s existing apt sources will be used if this option is not specified (this behaviour can be explicitly chosen by using the value of ‘distro’).


Keystone is often containerised. Here a single unit is deployed to a new container on machine ‘1’:

juju deploy --to lxd:1 keystone

Now connect the keystone application to an existing cloud database. The database application is determined by the series. Prior to focal percona-cluster is used, otherwise it is mysql-innodb-cluster. In the example deployment below mysql-innodb-cluster has been chosen.

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


The keystone:shared-db relation added at deployment time stores the Keystone admin password in the cloud database. By default this password is generated randomly but, for testing purposes, can be set via the admin-password configuration option. This option can also be used to view and change the password post-deployment.


This section covers Juju actions supported by the charm. Actions allow specific operations to be performed on a per-unit basis. To display action descriptions run juju actions keystone. If the charm is not deployed then see file actions.yaml.

  • openstack-upgrade
  • pause
  • resume
  • security-checklist

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.

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


Communication between Keystone and cloud services (as well as the OpenStack client) can be encrypted with TLS. Keystone also publishes API endpoints for the cloud (e.g. cinder, glance, keystone, neutron, nova, and placement), which may be TLS-based.

There are two methods for managing TLS keys and certificates:

  1. with Vault
  2. manually (via charm options)

Vault can set up private keys and server certificates for an application. It can also store a central CA certificate for the cloud. See the vault charm for more information.

Vault is the recommended method and is what will be covered here.

The private key and server certificate (and its signing) are enabled via a relation made to the vault application:

juju add-relation keystone:certificates vault:certificates

Other applications

Other applications can enable TLS by adding their own relation to Vault. Vault will issue certificates to the application and Keystone will update the corresponding API endpoint from HTTP to HTTPS.

For example, the Placement API:

juju add-relation placement:certificates vault:certificates

Note: API endpoints can be listed with openstack catalog list.


This charm supports the use of Juju Network Spaces, allowing the charm to be bound to network space configurations managed directly by Juju. This is only supported with Juju 2.0 and above.

API endpoints can be bound to distinct network spaces supporting the network separation of public, internal and admin endpoints.

Access to the underlying MySQL instance can also be bound to a specific space using the shared-db relation.

To use this feature, use the --bind option when deploying the charm:

juju deploy keystone --bind \
   "public=public-space \
    internal=internal-space \
    admin=admin-space \

Alternatively, these can also be provided as part of a Juju native bundle configuration:

      charm: cs:xenial/keystone
      num_units: 1
        public: public-space
        admin: admin-space
        internal: internal-space
        shared-db: internal-space

NOTE: Spaces must be configured in the underlying provider prior to attempting to use them.

NOTE: Existing deployments using os\-\*-network configuration options will continue to function; these options are preferred over any network space binding provided if set.

Policy Overrides

Policy overrides is an advanced feature that allows an operator to override the default policy of an OpenStack service. The policies that the service supports, the defaults it implements in its code, and the defaults that a charm may include should all be clearly understood before proceeding.

Caution: It is possible to break the system (for tenants and other services) if policies are incorrectly applied to the service.

Policy statements are placed in a YAML file. This file (or files) is then (ZIP) compressed into a single file and used as an application resource. The override is then enabled via a Boolean charm option.

Here are the essential commands (filenames are arbitrary):

zip overrides.zip override-file.yaml
juju attach-resource keystone policyd-override=overrides.zip
juju config keystone use-policyd-override=true

See appendix Policy Overrides in the OpenStack Charms Deployment Guide for a thorough treatment of this feature.


The charm supports the following relations. They are primarily of use to developers:

  • identity-admin: Used by charms to obtain the credentials for the admin user. This is intended for charms that automatically provision users, tenants, etc.

  • identity-credentials: Used by charms to obtain Keystone credentials without creating a service catalogue entry. Set ‘username’ only on the relation and Keystone will set defaults and return authentication details. Possible relation settings:

    • username: Username to be created.
    • project: Project (tenant) name to be created. Defaults to service’s project.
    • requested_roles: Comma-delimited list of roles to be created.
    • requested_grants: Comma-delimited list of roles to be granted. Defaults to Admin role.
    • domain: Keystone v3 domain the user will be created in. Defaults to the Default domain.
  • identity-notifications: Used to broadcast messages to services listening on the corresponding interface.

  • identity-service: Used by API endpoints to request an entry in the Keystone service catalogue and the endpoint template catalogue.

    Note: The identity-service relation is not used by Horizon (see keystone-service instead).

    When a relation is established Keystone receives the following data from the requesting API endpoint:

    • service_name
    • region
    • public_url
    • admin_url
    • internal_url

    Keystone verifies that the requested service is supported (the list of supported services should remain updated). The following will occur for a supported service:

    1. an entry in the service catalogue is created
    2. an endpoint template is created
    3. an admin token is generated.

    The API endpoint receives the token and is informed of the ports that Keystone is listening on.

  • keystone-service: Used only by Horizon. Horizon requests its configured default role and Keystone responds with a token. Horizon also receives the authentication and admin ports on which Keystone is listening.

  • nrpe-external-master: Used to generate Nagios checks.

Security Compliance config option “password-security-compliance”

The password-security-compliance configuration option sets the [security_compliance] section of Keystone’s configuration file.

The configuration option is a YAML dictionary, that is one level deep, with the following keys (and value formats).

lockout_failure_attempts: <int>
lockout_duration: <int>
disable_user_account_days_inactive: <int>
change_password_upon_first_use: <boolean>
password_expires_days: <int>
password_regex: <string>
password_regex_description: <string>
unique_last_password_count: <int>
minimum_password_age: <int>

It can be set by placing the keys and values in a file and then using the Juju command:

juju config keystone --file path/to/config.yaml

Note that, in this case, the config.yaml file requires the YAML key password-security-compliance: with the desired config keys and values on the following lines, indented for a dictionary.

Note: Please ensure that the page Security compliance and PCI-DSS is consulted before setting these options.

The charm will protect service accounts (accounts requested by other units that are in the service domain) against being forced to change their password. Operators should also ensure that any other accounts are protected as per the above referenced note.

If the config value cannot be parsed as YAML and/or the options are not able to be parsed as their indicated types then the charm will enter a blocked state until the config value is changed.

Token Support

As the keystone charm supports multiple releases of the OpenStack software, it also supports two Keystone token systems: UUID and Fernet. The capabilities are:

  • pre ‘ocata’: UUID tokens only.
  • ocata and pike: UUID or Fernet tokens, configured via the ‘token-provider’ configuration parameter.
  • rocky and later: Fernet tokens only.

Fernet tokens were added to OpenStack to solve the problem of Keystone being required to persist tokens to a common database (cluster) like UUID tokens, and solve the problem of size for PKI or PKIZ tokens.

For further information, please see Fernet - Frequently Asked Questions.

Theory of Operation

Fernet keys are used to generate tokens; they are generated by Keystone and have an expiration date. The key repository is a directory, and each key is an integer number, with the highest number being the primary key. Key ‘0’ is the staged key, that will be the next primary. Other keys are secondary keys.

New tokens are only ever generated from the primary key, whilst the secondary keys are used to validate existing tokens. The staging key is not used to generate tokens but can be used to validate tokens as the staging key might be the new primary key on the master due to a rotation and the keys have not yet been synchronised across all the units.

Fernet keys need to be rotated at periodic intervals, and the keys need to be synchronised to each of the other keystone units. Keys should only be rotated on the master keystone unit and must be synchronised before they are rotated again. Over rotation occurs if a unit rotates its keys such that there is no suitable decoding key on another unit that can decode a token that has been generated on the master. This happens if two key rotations are done on the master before a synchronisation has been successfully performed. This should be avoided. Over rotations can also cause validation keys to be removed before a token’s expiration which would result in failed validations.

There are 3 parts to the Key Rotation Strategy:

  1. The rotation frequency
  2. The token lifespan
  3. The number of active keys

There needs to be at least 3 keys as a minimum. The actual number of keys is determined by the token lifespan and the rotation frequency. The max_active_keys must be one greater than the token lifespan / rotation frequency

To quote from the FAQ:

    The number of max_active_keys for a deployment can be determined by
    dividing the token lifetime, in hours, by the frequency of rotation in
    hours and adding two. Better illustrated as:

Configuring Key Lifetime

In the keystone charm, the rotation frequency is calculated automatically from the token-expiration and the fernet-max-active-keys configuration parameters. For example, with an expiration of 24 hours and 6 active keys, the rotation frequency is calculated as:

token_expiration = 24   # actually 3600, as it's in seconds
max_active_keys = 6
rotation_frequency = token_expiration / (max_active_keys - 2)

Thus, the fernet-max-active-keys can never be less than 3 (which is enforced in the charm), which would make the rotation frequency the same as the token expiration time.

NOTE: To increase the rotation frequency, either increase fernet-max-active-keys or reduce token-expiration, and, to decrease rotation frequency, do the opposite.

NOTE: If the configuration parameters are used to significantly reduce the key lifetime, then it is possible to over-rotate the verification keys such that services will hold tokens that cannot be verified but haven’t yet expired. This should be avoided by only making small changes and verifying that current tokens will still be able to be verified. In particular, fernet-max-active-keys affects the rotation time.


When an older keystone charm is upgraded to this version, NO change will occur to the token system. That is, an ocata system will continue to use UUID tokens. In order to change the token system to Fernet, change the token-provider configuration item to fernet. This will switch the token system over. There may be a small outage in the control plane, but the running instances will be unaffected.


Please report bugs on Launchpad.

For general charm questions refer to the OpenStack Charm Guide.