Kubernetes to Bucket

• 1: Introduction
• 2: Configuration
• 3: Observability
• 4: API Reference

1 - Introduction

Kubernetes objects can be synchronized into a Bucket the kubernetes-to-bucket plugin.

Synchronization process

Special rules

There are no special rules for this synchronization plugin.

Blacklisted objects

There are some Kubernetes objects that are blacklisted by default and will be ignored by the synchronization process.

This is the list of the blacklisted objects:

• Namespaces which name starts with kube- or openshift , an the Namespace resiliency-operator.
• All namespaced objects inside a blacklisted Namespace.
• ConfigMaps named kube-root-ca.crt or openshift-service-ca.crt.

Objects path

Each Kubernetes object will be stored into a file with the following path: <group>.<version>.<kind>/<object_namespace>.<object_name>.

Examples:

• The Namespace named test will be saved in the file core.v1.Namespace/test.
• The Deployment named app-1 deployed in the test Namespace will be saved in the file apps.v1.Deployment/test.app-1.

Use cases

Backups

Backup your Kubernetes cluster to a Bucket to recover data when required.

Pilot light architecture

Synchronize applications to a Bucket and recover the applications in another cluster after a disaster.

2 - Configuration

Introduction

The synchronization process can be configured with some specific parameters using the .spec.config attribute.

apiVersion: automation.astronetes.io/v1alpha1
kind: Synchronization
metadata:
  name: example
spec:
  plugin: kubernetes-to-bucket
  config:
    ...

Required configuration

Source and destination

The source cluster and the destination bucket can be specified using the .spec.config.sourceName and .spec.config.destinationName properties. Both the KubernetesCluster and the bucket objects should exists in the same Namespace where the synchronization is being created.

Example:

apiVersion: automation.astronetes.io/v1alpha1
kind: Synchronization
metadata:
  name: example
spec:
  plugin: kubernetes-to-bucket
  config:
    sourceName: cluster-1
    destinationName: bucket-1
    ...

Optional configuration

Selectors

The resources that should be synchronized can be configured using the .spec.config.selectors property. If not configured, all resources will be included in the synchronization.

Example:

apiVersion: automation.astronetes.io/v1alpha1
kind: Synchronization
metadata:
  name: example
spec:
  plugin: kubernetes-to-bucket
  config:
    ...
    selectors:
      - target:
          version: v1
          resources:
            - namespaces
        objectSelector:
          labelSelector:
            matchLabels:
              disaster-recovery: "true"

Global selectors

Global selectors are used to set the default value on all selectors defined in .spec.config.selectors. They can be configured with the .spec.config.globalSelector property.

There are two options allowed, that can be configured at the same time:

• namespaceSelector: to set e dafult namespace selector for namespaced resources
• objectSelector: to set a default object selector for all resources

Example:

apiVersion: automation.astronetes.io/v1alpha1
kind: Synchronization
metadata:
  name: example
spec:
  plugin: kubernetes-to-bucket
  config:
    ...
    globalSelector:
      namespaceSelector:
        labelSelector:
          matchLabels:
            env: pro
      objectSelector:
        labelSelector:
          matchLabels:
            env: pro

Path prefix

The Kubernetes objects can be written in a subdirectory of the destination Bucket. The property .spec.config.pathPrefix allows this configuration.

Example:

apiVersion: automation.astronetes.io/v1alpha1
kind: Synchronization
metadata:
  name: example
spec:
  plugin: kubernetes-to-bucket
  config:
    ...
    pathPrefix: prefix-path

Log level

The log level of the Pod deployed to execute the synchronization, can be configured with the .spec.config.logLevel parameter.

Example:

apiVersion: automation.astronetes.io/v1alpha1
kind: Synchronization
metadata:
  name: example
spec:
  plugin: kubernetes-to-bucket
  config:
    ...
    logLevel: warn

Observability

Observability can be enaled using the specific .spec.config.observability parameter. For more information check the Observability page.

enabled: false
interval: 60s

Example:

apiVersion: automation.astronetes.io/v1alpha1
kind: Synchronization
metadata:
  name: example
spec:
  plugin: kubernetes-to-bucket
  config:
    ...
    observability:
      enabled: true
      interval: 2m

Limit assigned resources

For each synchronization, a new Pod is deployed inside the same Namespace. The limit and requests resources can be set using the .spec.config.resources field.

Example:

apiVersion: automation.astronetes.io/v1alpha1
kind: Synchronization
metadata:
  name: example
spec:
  plugin: kubernetes-to-bucket
  config:
    ...
    resources:
      requests:
        cpu: 1
        memory: 2Gi
      limits:
        cpu: 2
        memory: 2Gi

Concurrency

The concurrency parameter can be used to improve the peformance of the synchronization process with .spec.config.concurrency`.

Example:

apiVersion: automation.astronetes.io/v1alpha1
kind: Synchronization
metadata:
  name: example
spec:
  plugin: kubernetes-to-bucket
  config:
    ...
    concurrency: 200

Transformations

Kubernetes obejcts from the source cluster can be transformed before being synchronized into the destination bucket.

Example:

apiVersion: automation.astronetes.io/v1alpha1
kind: Synchronization
metadata:
  name: example
spec:
  plugin: kubernetes-to-bucket
  config:
    ...
    transformations:
      resources:
        - version: v1
          resources:
            - namespaces
      operations:
        - jsonpatch:
            operations:
              - op: add
                path: /metadata/labels/test-astrosync
                value: ok

3 - Observability

Introduction

The synchronization process exports many metrics in Prometheus format over HTTP.

Exported metrics

The following metrics are available:

Requirements

• The ServiceMonitor CRD from prometheus (servicemonitors.monitoring.coreos.com) must be enabled in the cluster where the operator is running.

Processes

Enable observability

Update the synchronization configuration, setting the paramente .spec.config.observability.enabled to true.

Once enabled the observability, a ServiceMonitor will be created in the same Namespace of the related synchronization.

Disable observability

Update the synchronization configuration, setting the paramente .spec.config.observability.enabled to false.

4 - API Reference

Config

Configuration for Kubernetes to Bucket synchronization

KubernetesGlobalSelector

Global selector is used to set the default value on all selectors. All defined selectors are combined using AND logic.

ObjectSelector

NameSelector

Select object by their name

LabelSelector

Select object by their labels

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

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.

SynchronizationOptions

Customize the synchronization process with special options

KubernetesObjectSelector

All defined selectors are combined using AND logic.

GroupVersionResources

Select a set of GroupVersionResource

Transformations

Transformations is a list of operations to modifiy the Kubernetes objects matching the given selectors

TransformationOperation

The operation to execute to transform the objects

OperationEnvVariable

EnvVariable operation

SetEnvOp

EnvVariableContainerSelector

ContainerSelectorType

OperationJSONPatch

The JSONPatch operation

JSONPatchOperation

JSONPAtch operation

OperationJSONPointer

JSONPointer operation

JSONPointerOperation