Stakater Playbook

Konfigurator

Diagram

Introduction

Konfigurator is an open source kubernetes operator developed by Stakateropen in new window that can dynamically generate app configuration when kubernetes resources change. We at stakater use konfigurator to create dynamic configuration for fluentd configmap.

Need

Sometimes there is a need to generate application configurations dynamically. e.g. using environment variables to decide on certain values and use them in pods as configmaps or secrets. This cannot be done using default kubernetes resources configmaps/secrets.

Solution

Konfigurator is a kubernetes operator that allows you to dynamically generate app configuration (configmap/secrets)when kubernetes resources change and then mounts these configmaps/secrets to given kubernetes resources.

Features

  • Use Custom Resource Definition CRD to enable Custom Resources CR to be created.
  • Render Configurations to
    • ConfigMap
    • Secret
  • Support for GO Templating Engine
  • Custom helper functions
  • Support to watch the following Kubernetes Resources
    • Pods
    • Services
    • Ingresses

Deploying to Kubernetes

Deploying Konfigurator requires:

  1. Deploying CRD to your cluster
  2. Deploying Konfigurator operator

You can deploy the CRD and operator on your kubernetes cluster via any of the following methods

  • Vanilla Manifests
  • Helm Chart (recommended)

Vanilla Manifests

You can apply vanilla manifests by running the following command

kubectl apply -f https://raw.githubusercontent.com/stakater/Konfigurator/master/deployments/kubernetes/konfigurator.yaml

Konfigurator by default looks for KonfiguratorTemplate only in the namespace where it is deployed, but it can be managed to work globally, you would have to change the WATCH_NAMESPACE environment variable to "" in the above manifest. e.g. change WATCH_NAMESPACE section to:

            - name: WATCH_NAMESPACE
              value: ""

Helm Charts

Alternatively if you have configured helm on your cluster, you can add konfigurator to helm from our public chart repository and deploy it via helm using below mentioned commands

helm repo add stakater https://stakater.github.io/stakater-charts

helm repo update

helm install stakater/konfigurator

Once Konfigurator is running, you can start creating resources supported by it. For details about its custom resources, look hereopen in new window.

To make Konfigurator work globally, you would have to change the WATCH_NAMESPACE environment variable to "" in values.yaml. e.g. change WATCH_NAMESPACE section to:

  env:
  - name: WATCH_NAMESPACE
    value: ""