Skip to content

Latest commit

 

History

History
112 lines (84 loc) · 3.63 KB

operator.rst

File metadata and controls

112 lines (84 loc) · 3.63 KB
Raw

Solution Operator guidelines

MetalK8s Solutions are a concept mostly centered around the Operator pattern. While there is no explicit requirements except the ones described below (see solution-operator-requirements), we recommend using the Operator SDK as it will embed best practices from the Kubernetes community.

Requirements

Files

All Operator-related files except for the container images (see solution-archive-images) should be stored under /operator in the ISO archive. Those files should be organized as follows:

operator
└── deploy
    ├── crds
    │   └── some_crd.yaml
    └── role.yaml

Most of these files are generated when using the Operator SDK.

Monitoring

MetalK8s does not handle the monitoring of a Solution application, which means:

  • the user, manually or through the Solution UI, should create Service and ServiceMonitor objects for each Operator instance
  • Operators should create Service and ServiceMonitor objects for each deployed component they own

The Prometheus Operator deployed by MetalK8s has cluster-scoped permissions, and is able to read the aforementioned ServiceMonitor objects to set up monitoring of your application services.

Configuration

Solution Operator must implement a --config option which will be used by MetalK8s to provide various useful information needed by the Operator, such as the endpoints for the container images. The given configuration looks like:

apiVersion: solutions.metalk8s.scality.com/v1alpha1
kind: OperatorConfig
repositories:
  <solution-version-x>:
    - endpoint: metalk8s-registry/<solution-name>-<solution-version-x>
      images:
        - <image-x>:<tag-x>
        - <image-y>:<tag-y>
  <solution-version-y>:
    - endpoint: metalk8s-registry/<solution-name>-<solution-version-y>
      images:
        - <image-x>:<tag-x>
        - <image-y>:<tag-y>

In example, for an online installation without MetalK8s providing the repository, this configuration could be:

apiVersion: solutions.metalk8s.scality.com/v1alpha1
kind: OperatorConfig
repositories:
  1.0.0:
    - endpoint: registry.scality.com/zenko
      images:
        - cloudserver:1.0.0
        - zenko-quorum:1.0.0
    - endpoint: quay.io/coreos
      images:
        - prometheus-operator:v0.34.0

This configuration allows the Operator to retrieve dynamically where the container images are stored for each version of a given Solution.

Roles

Solution must ship a role.yaml file located in /operator/deploy directory. This file is a manifest which declares all necessary Role and ClusterRole objects needed by the Operator. MetalK8s will take care of deploying these objects, create a ServiceAccount named <solution_name>-operator and all needed RoleBinding to bind these roles to this account.

Warning

Only Role and ClusterRole kinds are allowed in this file, the deployment of the Solution fails if any other resource is found.