Kubernetes Clusters

• 1: Import
• 2: Configurations
• 3: API Reference

1 - Import

Any kind of KubernetesCluster can be imported in the operator. Credentials are stored in Kubernetes secrets from which the KubernetesCluster collection access to connect to the clusters.

Once you have imported the KubernetesCluster, all the resources in the cluster that can be watched, will be read by the operator.

Requirements

• The kubeconfig file to access the cluster

Process

1. Create the Secret

Get the kubeconfig file that can be used to access the cluster, and save it as kubeconfig.yaml.

Then create the Secret with the following command:

kubectl create secret generic source --from-file=kubeconfig.yaml=kubeconfig.yaml

2. Create the KubernetesCluster

Define the KubernetesCluster object with the following YAML, and save it as cluster.yaml:

apiVersion: assets.astronetes.io/v1alpha1
kind: KubernetesCluster
metadata:
  name: cluster-1
spec:
  secretName: <secret_name>

Deploy the resource with the following command:

kubectl create -f cluster.yaml

2 - Configurations

Intro

The import of each KubernetesCluster can be configured with some specific parameters using the .spec.config attribute.

apiVersion: assets.astronetes.io/v1alpha1
kind: KubernetesCluster
metadata:
  name: my-cluster
spec:
  secretName: my-cluster-secret
  config: {}

Limit assigned resources

For each Kubernetes Cluster imported, a new Pod is deployed inside the same Namespace. The limit and requestsresources can be set using the.spec.config.resources` field.

Example:

apiVersion: assets.astronetes.io/v1alpha1
kind: KubernetesCluster
metadata:
  name: my-cluster
spec:
  secretName: my-cluster-secret
  config:
    resources:
      requests:
        cpu: 1
        memory: 2Gi
      limits:
        cpu: 2
        memory: 2Gi

Filter the watched resources

By default, the operator will watch all the available resources int he cluster that can be watched. You can filter the list of this resources by configuring the .spec.config.selectors field.

Example:

apiVersion: assets.astronetes.io/v1alpha1
kind: KubernetesCluster
metadata:
  name: my-cluster
spec:
  secretName: my-cluster-secret
  config:
    selectors:
      targets:
        - group: ""
          version: v1
          resources:
            - namespaces
            - secrets
            - configmaps
            - serviceaccounts
            - resourcequotas
            - limitranges
            - persistentvolumeclaims
        - group: policy
          version: v1
          resources:
            - poddisruptionbudgets

Concurrency

The concurrency parameter can be used to improve the peformance of the operator on listening the changes that happens in the Kubernetes Cluster.

Example:

apiVersion: assets.astronetes.io/v1alpha1
kind: KubernetesCluster
metadata:
  name: my-cluster
spec:
  secretName: my-cluster-secret
  config:
    concurrency: 200

3 - API Reference

Config

Customize the integration with a KubernetesCluster

ObservabilityConfig

Configure the synchronization process observability using Prometheus ServiceMonitor

Duration

Duration is a wrapper around time.Duration which supports correct marshaling to YAML and JSON. In particular, it marshals into strings, which can be used as map keys in json.

KubernetesClusterSelectors

Filter the Kubernetes objects that should be read from the cluster. All defined selectors are combined using AND logic.

ObjectSelector

NameSelector

Select object by their name

LabelSelector

A label selector is a label query over a set of resources. The result of matchLabels and matchExpressions are ANDed. An empty label selector matches all objects. A null label selector matches no objects. +structType=atomic

LabelSelectorRequirement

A label selector requirement is a selector that contains values, a key, and an operator that relates the key and values.

LabelSelectorOperator

A label selector operator is the set of operators that can be used in a selector requirement.

NamespaceSelector

GroupVersionResources

Select a set of GroupVersionResource