Mirantis Container Cloud (MCC) becomes part of Mirantis OpenStack for Kubernetes (MOSK)!
Starting with MOSK 25.2, the MOSK documentation set covers all product layers, including MOSK management (formerly Container Cloud). This means everything you need is in one place. Some legacy names may remain in the code and documentation and will be updated in future releases. The separate Container Cloud documentation site will be retired, so please update your bookmarks for continued easy access to the latest content.
OpenStack message bus¶
The internal components of Mirantis OpenStack for Kubernetes (MOSK) coordinate their operations and exchange status information using the cluster’s message bus (RabbitMQ).
Exposable OpenStack notifications¶
Available since MOSK 22.5
MOSK enables you to configure OpenStack services to emit
notification messages to the MOSK cluster messaging bus
(RabbitMQ) every time an OpenStack resource, for example, an instance, image,
and so on, changes its state due to a cloud user action or through its
lifecycle. For example, MOSK Compute service (OpenStack
Nova) can publish the instance.create.end notification once a newly created
instance is up and running.
Note
In certain cases, RabbitMQ notifications may prove unreliable, such as when the RabbitMQ server undergoes a restart or when communication between the server and the client reading the notifications breaks down. To optimize reliability, Mirantis suggests using multiple channels to store notification events, encompassing:
- StackLight notifications 
- Storing audit as part of the OpenStack logs 
Sample of an instance.create.end notification
{
    "event_type": "instance.create.end",
    "payload": {
        "nova_object.data": {
            "action_initiator_project": "6f70656e737461636b20342065766572",
            "action_initiator_user": "fake",
            "architecture": "x86_64",
            "auto_disk_config": "MANUAL",
            "availability_zone": "nova",
            "block_devices": [],
            "created_at": "2012-10-29T13:42:11Z",
            "deleted_at": null,
            "display_description": "some-server",
            "display_name": "some-server",
            "fault": null,
            "flavor": {
             "nova_object.data": {
              "description": null,
              "disabled": false,
              "ephemeral_gb": 0,
              "extra_specs": {
                  "hw:watchdog_action": "disabled"
              },
              "flavorid": "a22d5517-147c-4147-a0d1-e698df5cd4e3",
              "is_public": true,
              "memory_mb": 512,
              "name": "test_flavor",
              "projects": null,
              "root_gb": 1,
              "rxtx_factor": 1.0,
              "swap": 0,
              "vcpu_weight": 0,
              "vcpus": 1
             },
             "nova_object.name": "FlavorPayload",
             "nova_object.namespace": "nova",
             "nova_object.version": "1.4"
            },
            "host": "compute",
            "host_name": "some-server",
            "image_uuid": "155d900f-4e14-4e4c-a73d-069cbf4541e6",
            "instance_name": "instance-00000001",
            "ip_addresses": [
             {
              "nova_object.data": {
                  "address": "192.168.1.3",
                  "device_name": "tapce531f90-19",
                  "label": "private",
                  "mac": "fa:16:3e:4c:2c:30",
                  "meta": {},
                  "port_uuid": "ce531f90-199f-48c0-816c-13e38010b442",
                  "version": 4
              },
              "nova_object.name": "IpPayload",
              "nova_object.namespace": "nova",
              "nova_object.version": "1.0"
             }
            ],
            "kernel_id": "",
            "key_name": "my-key",
            "keypairs": [
             {
              "nova_object.data": {
                  "fingerprint": "1e:2c:9b:56:79:4b:45:77:f9:ca:7a:98:2c:b0:d5:3c",
                  "name": "my-key",
                  "public_key": "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAAAgQDx8nkQv/zgGgB4rMYmIf+6A4l6Rr+o/6lHBQdW5aYd44bd8JttDCE/F/pNRr0lRE+PiqSPO8nDPHw0010JeMH9gYgnnFlyY3/OcJ02RhIPyyxYpv9FhY+2YiUkpwFOcLImyrxEsYXpD/0d3ac30bNH6Sw9JD9UZHYcpSxsIbECHw== Generated-by-Nova",
                  "type": "ssh",
                  "user_id": "fake"
              },
              "nova_object.name": "KeypairPayload",
              "nova_object.namespace": "nova",
              "nova_object.version": "1.0"
             }
            ],
            "launched_at": "2012-10-29T13:42:11Z",
            "locked": false,
            "locked_reason": null,
            "metadata": {},
            "node": "fake-mini",
            "os_type": null,
            "power_state": "running",
            "progress": 0,
            "ramdisk_id": "",
            "request_id": "req-5b6c791d-5709-4f36-8fbe-c3e02869e35d",
            "reservation_id": "r-npxv0e40",
            "state": "active",
            "tags": [
             "tag"
            ],
            "task_state": null,
            "tenant_id": "6f70656e737461636b20342065766572",
            "terminated_at": null,
            "trusted_image_certificates": [
             "cert-id-1",
             "cert-id-2"
            ],
            "updated_at": "2012-10-29T13:42:11Z",
            "user_id": "fake",
            "uuid": "178b0921-8f85-4257-88b6-2e743b5a975c"
        },
        "nova_object.name": "InstanceCreatePayload",
        "nova_object.namespace": "nova",
        "nova_object.version": "1.12"
    },
    "priority": "INFO",
    "publisher_id": "nova-compute:compute"
}
OpenStack notification messages can be consumed and processed by various corporate systems to integrate MOSK clouds into the company infrastructure and business processes.
The list of the most common use cases includes:
- Using notification history for retrospective security audit 
- Using the real-time aggregation of notification messages to gather statistics on cloud resource consumption for further capacity planning 
Cloud billing considerations
Notifications alone should not be considered as a source of data for any kind of financial reporting. The delivery of the messages can not be guaranteed due to various technical reasons. For example, messages can be lost if an external consumer is not fetching them from the queue fast enough.
Mirantis strongly recommends that your cloud billing solutions rely on the combination of the following data sources:
- Periodic polling of the OpenStack API as a reliable source of information about allocated resources 
- Subscription to notifications to receive timely updates about the resource status change 
If you are looking for a ready-to-use billing solution for your cloud, contact Mirantis or one of our partners.
A cloud administrator can securely expose part of a MOSK cluster message bus to the outside world. This enables an external consumer to subscribe to the notification messages emitted by the cluster services.
Important
The latest OpenStack release available in MOSK supports notifications from the following services:
- Block storage (OpenStack Cinder) 
- DNS (OpenStack Designate) 
- Image (OpenStack Glance) 
- Orchestration (OpenStack Heat) 
- Bare Metal (OpenStack Ironic) 
- Identity (OpenStack Keystone) 
- Shared Filesystems (OpenStack Manila) 
- Instance High Avalability (OpenStack Masakari) 
- Networking (OpenStack Neutron) 
- Compute (OpenStack Nova) 
To enable the external notification endpoint, add the following structure
to the OpenStackDeployment custom resource. For example:
spec:
  features:
    messaging:
      notifications:
        external:
          enabled: true
          topics:
            - external-consumer-A
            - external-consumer-2
For each topic name specified in the topics field, MOSK
creates a topic exchange in its RabbitMQ cluster together with a set of queues
bound to this topic. All enabled MOSK services will
publish their notification messages to all configured topics so that
multiple consumers can receive the same messages in parallel.
A topic name must follow Kubernetes standard format for object names and IDs
that is only lowercase alphanumeric characters, -, or . The topic
name notifications is reserved for the internal use.
MOSK supports the connection to message bus (RabbitMQ) through an encrypted or non-encrypted endpoint. Once connected, it supports authentication through either a plain text user name and password or mutual TLS authentication using encrypted X.509 client certificates.
Each topic exchange is protected by automatically generated authentication
credentials and certificates for secure connection that are stored as a secret
in the openstack-external namespace of a MOSK underlying
Kubernetes cluster. A secret is identified by the name of the topic. The list
of attributes for the secret object includes:
- hosts
- The IP addresses which an external notification endpoint is available on 
 
- port_amqp,- port_amqp-tls
- The TCP ports which external notification endpoint is available on 
 
- vhost
- The name of the RabbitMQ virtual host which the topic queues are created on 
 
- username,- password
- Authentication data 
 
- ca_cert
- The client CA certificate 
 
- client_cert
- The client certificate 
 
- client_key
- The client private key 
 
For the configuration example above, the following objects will be created:
kubectl -n openstack-external get secret
NAME                                            TYPE           DATA   AGE
openstack-external-consumer-A-notifications     Opaque         4      4m51s
openstack-external-consumer-2-notifications     Opaque         4      4m51s