C5C3 - CobaltCore

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Infrastructure Service Operators ​

Runs in: Control Plane Cluster Deployment: Via FluxCD (HelmRelease) Instance Creation: By c5c3-operator (creates CRs)

The OpenStack Control Plane requires several infrastructure services as backend. The Operators are deployed separately via FluxCD, while the c5c3-operator creates and manages the corresponding Custom Resources (instances).

text
┌───────────────────────────────────────────────────────────────────┐
│           Infrastructure Services (Control Plane Cluster)         │
├───────────────────────────────────────────────────────────────────┤
│                                                                   │
│  FluxCD deployed Operators:                                       │
│  ┌─────────────┐  ┌─────────────┐  ┌─────────────┐  ┌───────────┐ │
│  │   MariaDB   │  │   Valkey    │  │  RabbitMQ   │  │ Memcached │ │
│  │  Operator   │  │  Operator   │  │  Operator   │  │ Operator  │ │
│  │ (HelmRelease│  │ (HelmRelease│  │ (HelmRelease│  │(HelmRel.) │ │
│  └──────┬──────┘  └──────┬──────┘  └──────┬──────┘  └─────┬─────┘ │
│         │                │                │              │        │
│         │  watched CRs   │  watched CRs   │  watched CRs │        │
│         │                │                │              │        │
│  c5c3-operator creates CRs:                                       │
│  ┌──────▼──────┐  ┌──────▼──────┐  ┌──────▼──────┐  ┌─────▼─────┐ │
│  │   MariaDB   │  │   Valkey    │  │  RabbitMQ   │  │ Memcached │ │
│  │     CR      │  │     CR      │  │     CR      │  │    CR     │ │
│  │             │  │             │  │             │  │           │ │
│  │ ┌─────────┐ │  │ ┌─────────┐ │  │ ┌─────────┐ │  │┌─────────┐│ │
│  │ │ Galera  │ │  │ │Sentinel │ │  │ │ Cluster │ │  ││Deploym. ││ │
│  │ │ Cluster │ │  │ │+ Valkey │ │  │ │  Nodes  │ │  ││+ Service││ │
│  │ └─────────┘ │  │ └─────────┘ │  │ └─────────┘ │  │└─────────┘│ │
│  └──────┬──────┘  └──────┬──────┘  └──────┬──────┘  └─────┬─────┘ │
│         │                │                │              │        │
│         └────────────────┴────────────────┴──────────────┘        │
│                                   │                               │
│                                   ▼                               │
│  ┌─────────────────────────────────────────────────────────────┐  │
│  │      OpenStack Services (via dedicated Service-Operators)   │  │
│  │  Nova, Neutron, Keystone, Glance, Cinder, Placement         │  │
│  └─────────────────────────────────────────────────────────────┘  │
│                                                                   │
└───────────────────────────────────────────────────────────────────┘

MariaDB Operator ​

Repository: github.com/mariadb-operator/mariadb-operatorLicense: MIT

The MariaDB Operator enables declarative management of MariaDB clusters with high availability.

Key Features:

  • Galera Clustering: Synchronous multi-master replication
  • MaxScale Integration: Proxy, load balancing, automatic failover
  • Backup & Restore: mariadb-backup, mariadb-dump, S3-compatible backends
  • Point-in-Time Recovery: Restore to specific point in time
  • TLS: Integrated cert-manager support
  • Monitoring: mysqld-exporter for Prometheus

Example:

yaml
apiVersion: k8s.mariadb.com/v1alpha1
kind: MariaDB
metadata:
  name: openstack-db
spec:
  replicas: 3
  galera:
    enabled: true
  maxScale:
    enabled: true
    replicas: 2
  storage:
    size: 100Gi
    storageClassName: ceph-rbd
  metrics:
    enabled: true

Valkey Operator (SAP) ​

Repository: github.com/SAP/valkey-operatorHelm Chart: github.com/SAP/valkey-operator-helmLicense: Apache 2.0

The Valkey Operator (SAP) enables declarative Valkey deployments with Sentinel-based failover via a single Valkey CRD.

Key Features:

  • Sentinel Mode: Automatic failover with Sentinel sidecars
  • Primary-Replica Mode: Static topology without Sentinel
  • TLS: Self-signed or cert-manager integration
  • AOF Persistence: Configurable StorageClasses (immutable after creation)
  • Monitoring: redis-exporter sidecar (Port 9121) with ServiceMonitor/PrometheusRule
  • Binding Secret: Automatic generation of connection information

Example (Sentinel Mode for OpenStack):

yaml
apiVersion: cache.cs.sap.com/v1alpha1
kind: Valkey
metadata:
  name: openstack-valkey
spec:
  replicas: 3
  sentinel:
    enabled: true
  tls:
    enabled: true
  metrics:
    enabled: true
    monitor:
      enabled: true

RabbitMQ Cluster Operator ​

Repository: github.com/rabbitmq/cluster-operatorLicense: MPL-2.0 (official from Broadcom/VMware)

The official RabbitMQ Operator for Kubernetes with comprehensive lifecycle management.

Key Features:

  • Cluster Formation: Automatic cluster creation and management
  • Graceful Upgrades: Rolling updates without downtime
  • Policies & Users: Declarative configuration via CRDs
  • Observability: Integrated monitoring and logging
  • TLS: Encrypted communication

Example:

yaml
apiVersion: rabbitmq.com/v1beta1
kind: RabbitmqCluster
metadata:
  name: openstack-rabbitmq
spec:
  replicas: 3
  resources:
    requests:
      memory: 2Gi
      cpu: 1000m
  persistence:
    storageClassName: ceph-rbd
    storage: 50Gi
  rabbitmq:
    additionalConfig: |
      cluster_partition_handling = pause_minority

Memcached Operator ​

Repository: github.com/C5C3/memcached-operatorLicense: Apache 2.0

The Memcached Operator enables declarative management of Memcached instances with support for high availability, TLS, monitoring, and security policies.

Key Features:

  • Declarative Management: Memcached CR defines desired cluster state
  • High Availability: Pod anti-affinity, topology spreading, PodDisruptionBudgets
  • Monitoring: Prometheus exporter sidecar with ServiceMonitor support
  • Security: TLS encryption, SASL authentication, NetworkPolicy
  • Headless Service: DNS-based pod discovery for pymemcache HashClient

Example (Memcached CR):

yaml
apiVersion: memcached.c5c3.io/v1alpha1
kind: Memcached
metadata:
  name: openstack-memcached
spec:
  replicas: 3
  image: memcached:1.6
  config:
    maxMemoryMB: 1024
    maxConnections: 4096
  resources:
    requests:
      memory: 1Gi
      cpu: 500m
  highAvailability:
    podAntiAffinity: soft
    podDisruptionBudget:
      minAvailable: 2
  monitoring:
    enabled: true
    exporter:
      image: prom/memcached-exporter:latest

Further Reading ​