service-proxy-operator

README

service-proxy-operator

This service-proxy-operator is a simple Operator to allow deploying a Nginx proxy to a Kubernetes ingress to services endpoints.

Description

This is a sample project made in a couple of days for interview purposes. This project is not meant to be a full Kubernetes Operator and only outlines the basic features of an Operator. It is based off the Operator Framework SDK. Operator Framework defines capability levels. Per this framework, the service-proxy-operator is only a Level 1 operator, with some Level 2 features.

Features

The service-proxy-operator uses a ServiceProxy Custom Resource Definition to deploy a Nginx proxy Deployment and attached service for the services listed in the CRD. This allows to expose all the services from a single endpoint.

Every service defines endpoints such as: [service].[namespace].svc.cluster.local. Given two services foo and bar in the default namespace`, you can create the ServiceProxy CRD such as:

apiVersion: cache.service-proxy-operator.local/v1alpha1
kind: ServiceProxy
metadata:
  name: serviceproxy-sample
spec:
  serviceNames:
    - bar
    - foo

The Operator will then create the necessary resources, to allow to query each service at http://serviceproxy-sample-service.default.svc.cluster.local/[foo|bar]/. It also creates an Ingress Object pointing to that service allowing to reach the services from outside the cluster.

If you have an ingress gateway setup to your cluster, you can then query your sevice like curl http://[cluster]/foo/

Operator Capabilities

This demonstration operator only does simple tasks such as:

• Create the necessary resource (Deployment, Service, ConfigMap, Ingress) upon creating the ServiceProxy CR.
• Update the ConfigMap whenever the CR changes (to apply)

Getting Started

You’ll need a Kubernetes cluster to run against. You can use KIND to get a local cluster for testing, or run against a remote cluster. Note: Your controller will automatically use the current context in your kubeconfig file (i.e. whatever cluster kubectl cluster-info shows).

You can use ./hack/kind-start.sh to start a kind cluster with a localhost:80 ingress gateway, along with a local image registry.

Running on the cluster

The following Makefile makes use of the local image registry by default. Overwrite it by setting IMG=<some-registry>/service-proxy-operator:tag in make commands.

1. Build and push the operator:

make docker-build docker-push

1. Deploy to the cluster in the current kubernetes context:

make deploy

1. Install sample Instances of Custom Resources:

The sample CR deploys agnhost for testing purposes

kubectl apply -f config/samples/

1. Query the services

The Hostnames are the same as we're using two services pointing to the same pod.

$> curl localhost/agnhost/hostname
agnhost-55755b8ff-kxhg8
$> curl localhost/other-agnhost/hostname
agnhost-55755b8ff-kxhg8

Uninstall CRDs

To delete the CRDs from the cluster:

make uninstall

Undeploy controller

UnDeploy the controller to the cluster:

make undeploy

License

Copyright 2023.

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.