# Overview This principle charm provides the OpenStack Neutron API service which was previously provided by the nova-cloud-controller charm. When this charm is related to the nova-cloud-controller charm the nova-cloud controller charm will shutdown its api service, de-register it from keystone and inform the compute nodes of the new neutron url. # Usage To deploy (partial deployment only): juju deploy neutron-api juju deploy neutron-openvswitch juju add-relation neutron-api mysql juju add-relation neutron-api rabbitmq-server juju add-relation neutron-api neutron-openvswitch juju add-relation neutron-api nova-cloud-controller This charm also supports scale out and high availability using the hacluster charm: juju deploy hacluster neutron-hacluster juju add-unit neutron-api juju config neutron-api vip= juju add-relation neutron-hacluster neutron-api ## High availability When more than one unit is deployed with the [hacluster][hacluster-charm] 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][cdg-ha-apps] in the [OpenStack Charms Deployment Guide][cdg] for details. # Restrictions This charm only support deployment with OpenStack Icehouse or better. # Internal DNS for Cloud Guests The charm supports enabling internal DNS resolution for cloud guests in accordance with the OpenStack DNS integration guide. To enable internal DNS resolution, the 'enable-ml2-dns' option must be set to True. When enabled, the domain name specified in the 'dns-domain' will be advertised as the nameserver search path by the DHCP agents. The Nova compute service will leverage this functionality when enabled. When ports are allocated by the compute service, the dns_name of the port is populated with a DNS sanitized version of the instance's display name. The Neutron DHCP agents will then create host entries in the dnsmasq's configuration files matching the dns_name of the port to the IP address associated with the port. Note that the DNS nameserver provided to the instance by the DHCP agent depends on the tenant's network setup. The Neutron DHCP agent only advertises itself as a nameserver when the Neutron subnet does not have nameservers configured. If additional nameservers are needed and internal DNS is desired, then the IP address of the DHCP port should be added to the subnet's list of configured nameservers. For more information refer to the OpenStack documentation on [DNS Integration](https://docs.openstack.org/ocata/networking-guide/config-dns-int.html). # External DNS for Cloud Guests To add support for DNS record auto-generation when Neutron ports and floating IPs are created the charm needs a relation with designate charm: juju deploy designate juju add-relation neutron-api designate In order to enable the creation of reverse lookup (PTR) records, enable "reverse-dns-lookup" charm option: juju config neutron-api reverse-dns-lookup=True and configure the following charm options: juju config neutron-api ipv4-ptr-zone-prefix-size= juju config neutron-api ipv6-ptr-zone-prefix-size= For example, if prefix sizes of your IPv4 and IPv6 subnets are "24" (e.g. "192.168.0.0/24") and "64" (e.g. "fdcd:06ca:e498:216b::/64") respectively, configure the charm options as follows: juju config neutron-api ipv4-ptr-zone-prefix-size=24 juju config neutron-api ipv6-ptr-zone-prefix-size=64 For more information refer to the OpenStack documentation on [DNS Integration](https://docs.openstack.org/ocata/networking-guide/config-dns-int.html) # Spaces 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 neutron-api --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: ```yaml neutron-api: charm: cs:xenial/neutron-api 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. # Additional Middleware Requests by Neutron Plugin Charms Some neutron plugins may require additional middleware to be added to api-paste.ini. In order to support that a subordinate may pass extra_middleware via the neutron-plugin-api-subordinate relation. Relation data to be set by subordinates: {'extra_middleware': [{ 'type': 'middleware_type', 'name': 'middleware_name', 'config': { 'setting_1': 'value_1', 'setting_2': 'value_2'}}]} It would not be correct to do that from your own plugin as this requires the neutron-api service restart which should be handled in this charm. The developer guide for Neutron contains a description of the startup process which makes it clear that api-paste.ini is parsed only once in neutron-api's lifetime (see the "WSGI Application" section): https://opendev.org/openstack/neutron/src/branch/master/doc/source/contributor/internals/api_layer.rst For the api-paste.ini format in general, please consult PasteDeploy repository docs/index.txt, "Config Format" section: https://github.com/Pylons/pastedeploy Classes in loadwsgi.py contain config_prefixes that can be used for middleware types - these are the prefixes the charm code validates passed data against: https://github.com/Pylons/pastedeploy/blob/master/paste/deploy/loadwsgi.py ## 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 neutron-api policyd-override=overrides.zip juju config neutron-api use-policyd-override=true See appendix [Policy Overrides][cdg-appendix-n] in the [OpenStack Charms Deployment Guide][cdg] for a thorough treatment of this feature. # Bugs Please report bugs on [Launchpad][lp-bugs-charm-neutron-api]. For general charm questions refer to the OpenStack [Charm Guide][cg]. [cg]: https://docs.openstack.org/charm-guide [cdg]: https://docs.openstack.org/project-deploy-guide/charm-deployment-guide [cdg-appendix-n]: https://docs.openstack.org/project-deploy-guide/charm-deployment-guide/latest/app-policy-overrides.html [lp-bugs-charm-neutron-api]: https://bugs.launchpad.net/charm-neutron-api/+filebug [hacluster-charm]: https://jaas.ai/hacluster [cdg-ha-apps]: https://docs.openstack.org/project-deploy-guide/charm-deployment-guide/latest/app-ha.html#ha-applications