Overview

This charm provides Keystone, the Openstack identity service. It's target platform is (ideally) Ubuntu LTS + Openstack.

Usage

The following interfaces are provided:

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

- identity-service: Openstack API endpoints request an entry in the 
  Keystone service catalog + endpoint template catalog. When a relation
  is established, Keystone receives: service name, region, public_url,
  admin_url and internal_url. It first checks that the requested service
  is listed as a supported service. This list should stay updated to
  support current Openstack core services. If the service is supported,
  an entry in the service catalog is created, an endpoint template is
  created and a admin token is generated. The other end of the relation
  receives the token as well as info on which ports Keystone is listening
  on.

- keystone-service: This is currently only used by Horizon/dashboard
  as its interaction with Keystone is different from other Openstack API
  services. That is, Horizon requests a Keystone role and token exists.
  During a relation, Horizon requests its configured default role and
  Keystone responds with a token and the auth + admin ports on which
  Keystone is listening.

- identity-admin: Charms use this relation to obtain the credentials
  for the admin user. This is intended for charms that automatically
  provision users, tenants, etc. or that otherwise automate using the
  Openstack cluster deployment.

- identity-notifications: Used to broadcast messages to any services
  listening on the interface.

- identity-credentials: Charms use this relation to obtain keystone
  credentials without creating a service catalog 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 services
             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.

Database

Keystone requires a database. By default, a local sqlite database is used. The charm supports relations to a shared-db via mysql-shared interface. When a new data store is configured, the charm ensures the minimum administrator credentials exist (as configured via charm configuration)

HA/Clustering

There are two mutually exclusive high availability options: using virtual IP(s) or DNS. In both cases, a relationship to hacluster is required which provides the corosync back end HA functionality.

To use virtual IP(s) the clustered nodes must be on the same subnet such that the VIP is a valid IP on the subnet for one of the node's interfaces and each node has an interface in said subnet. The VIP becomes a highly-available API endpoint.

At a minimum, the config option 'vip' must be set in order to use virtual IP HA. If multiple networks are being used, a VIP should be provided for each network, separated by spaces. Optionally, vip_iface or vip_cidr may be specified.

To use DNS high availability there are several prerequisites. However, DNS HA does not require the clustered nodes to be on the same subnet. Currently the DNS HA feature is only available for MAAS 2.0 or greater environments. MAAS 2.0 requires Juju 2.0 or greater. The clustered nodes must have static or "reserved" IP addresses registered in MAAS. The DNS hostname(s) must be pre-registered in MAAS before use with DNS HA.

At a minimum, the config option 'dns-ha' must be set to true and at least one of 'os-public-hostname', 'os-internal-hostname' or 'os-internal-hostname' must be set in order to use DNS HA. One or more of the above hostnames may be set.

The charm will throw an exception in the following circumstances: If neither 'vip' nor 'dns-ha' is set and the charm is related to hacluster If both 'vip' and 'dns-ha' are set as they are mutually exclusive If 'dns-ha' is set and none of the os-{admin,internal,public}-hostname(s) are set

SSL/HTTPS

This charm also supports SSL and HTTPS endpoints. In order to ensure SSL certificates are only created once and distributed to all units, one unit gets elected as an ssl-cert-master. One side-effect of this is that as units are scaled-out the currently elected leader needs to be running in order for nodes to sync certificates. This 'feature' is to work around the lack of native leadership election via Juju itself, a feature that is due for release some time soon but until then we have to rely on this. Also, if a keystone unit does go down, it must be removed from Juju i.e.

juju destroy-unit keystone/<unit-num>

Otherwise it will be assumed that this unit may come back at some point and therefore must be know to be in-sync with the rest before continuing.

Network Space support

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 shared-db=internal-space"

alternatively these can also be provided as part of a juju native bundle configuration:

keystone:
  charm: cs:xenial/keystone
  num_units: 1
  bindings:
    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.