cloud-config-operator

Cloud Config Operator

Provision Kubernetes applications using Spring Cloud Config Server with a GitOps approach.

Custom Resource Definition

The CloudConfig CRD defines one or more Spring Cloud Config Apps that that Cloud Config Operator will monitor and synchronize with the cluster state.

CloudConfig CRD example:

apiVersion: k8.jabberwocky.se/v1alpha1
kind: CloudConfig
metadata:
  name: test
spec:
  server: cloud-config-server:8888  # Cloud Config Server name or URL
  secert: cloud-config              # Cloud Config Server secret
  label: master                     # label used for all apps, defaults to 'master'
  specFile: deployment.yaml         # app spec file, defaults to 'deployment.yaml'
  appName: cluster                  # application name, defaults to the CloudConfig name
  appList: services                 # application list property of AppName app
  insecure: true                    # do not require or verify SSL server certificates

  environments:                     # Environments where apps are managed, global values can be overridden
    dev:                            # Map key is used as the environment's name
      profile: [ dev ]              # cloud config profiles for the env
    prd:
      profile: [ prd ]

Usage

Cloud Config Apps exist in a number of environments. Each environment is defined by a list of profiles and a label.

For each environment in environments, Spring Cloud Operator will

• Retrieve the app's specFile from the Spring Cloud Config Server
• Apply the specFile to the Kubernetes cluster

App or List of Apps

A CloudConfig can either define a single App or a list of Apps.

In the first case the appName is the name of the Spring Cloud Config application

In the second case the appName defines the application that contains a single configuration property appList that lists the Apps to manage. This property can have different values in different environments.

Environments and namespaces

TODO

Versioning per environment

TODO

Different spec files per environment

TODO

REST API

(!) Planned for v0.3!

Refresh config for all apps in all environments

POST /config/{name}

Optionally a JSON message in the body of the HTTP request can be used to restrict what environments and apps are refreshed.

{
  "label": "develop",
  "env": [ "dev" ],
  "app": [ "alpha", "beta" ]
}

• label - only environments with a matching label are affected.
• env - only environments provided in the array are affected
• app - only applications provided in the array are affected

Refresh config for all apps in a given environment

POST /config/{name}/env/{env}

Refresh config for all apps and all environments using a given label

POST /config/{name}/label/{label}

Refresh config for a single app in a given environment

POST /config/{name}/env/{env}/app/{app}

Refresh config for a single app in all environments

POST /config/{name}/app/{app}

Project Setup

The following instructions assume Mac OS X with Home Brew and a local Minikube as the development Kubernetes cluster:

brew install cask minikube
brew install kubernetes-cli
brew install docker
brew install golang dep

Once you have a working Go environment you can get the project using

go get github.com/chrsoo/cloud-config-operator

To setup the Operator SDK please follow the Quick Start instsructions on GitHub!

Roadmap

• v0.1 CloudConfig CRD for managing Spring Cloud Config apps. Experimental version based on CronJob and Kubectl to get things going.
• v0.2 CloudConfigEnv CRD replaces CronJob.
• v0.3 REST API for CI/CD integrations
• v0.4 CloudConfigApp CRD removes the kubectl dependency
• v1.0 The first stable version of cloud-config-operator resource API

References

• operator-sdk
• Quick Intro to Spring Cloud Config
• Best practices for building Kubernetes Operators and stateful apps