main.go

/*
Copyright 2017 Kamesh Sampath<kamesh.sampath@hotmail.com>

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.
*/

package main

import (
	"flag"
	"os"
	"path/filepath"
	"strings"

	"k8s.io/client-go/rest"

	"k8s.io/client-go/pkg/api/v1"
	"k8s.io/client-go/util/workqueue"

	"github.com/kameshsampath/checontroller/che"

	"k8s.io/apimachinery/pkg/fields"
	"k8s.io/client-go/kubernetes"
	"k8s.io/client-go/tools/cache"
	"k8s.io/client-go/tools/clientcmd"
	"k8s.io/client-go/util/homedir"

	log "github.com/sirupsen/logrus"
	meta_v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
)

func init() {
	log.SetFormatter(&log.JSONFormatter{})
	log.SetOutput(os.Stdout)
	log.SetLevel(log.InfoLevel)
}

func main() {

	var kubeconfig, podNamespace, cheEndpointURI, newStackURL *string

	var incluster *bool

	var clientset *kubernetes.Clientset

	home := homedir.HomeDir()

	//fmt.Printf("Home Dir :%s\n", home)

	kubeconfig = flag.String("kubeconfig", filepath.Join(home, ".kube", "config"), "(optional) absolute path to the kubeconfig file")

	//TODO - get the selectors from user
	incluster = flag.Bool("incluster", false, "Whether the application is deployed inside Kubernetes cluster or outside")
	podNamespace = flag.String("namespace", "", "The Kubernetes Namespace to use")
	cheEndpointURI = flag.String("cheEndpointURI", "", "The Che EndpointURI")
	newStackURL = flag.String("newStackURL", "https://raw.githubusercontent.com/redhat-developer/rh-che/master/assembly/fabric8-stacks/src/main/resources/stacks.json", "The New Stacks URL")

	flag.Parse()

	if *incluster {
		log.Infoln("Accessing from inside cluster")
		config, err := rest.InClusterConfig()
		if err != nil {
			log.Fatalf("Unable to build kubeconfig %s", err)
		}
		clientset, err = kubernetes.NewForConfig(config)
		if err != nil {
			log.Fatalf("Unable to build client %s", err)
		}
		*podNamespace = os.Getenv("KUBERNETES_NAMESPACE")
	} else {
		log.Infoln("Accessing from outside cluster")
		config, err := clientcmd.BuildConfigFromFlags("", *kubeconfig)

		if err != nil {
			log.Fatalf("Unable to build kubeconfig %s", err)
		}
		if *podNamespace == "" {
			*podNamespace = defaultNamespaceFromConfig(kubeconfig)
		}
		//creates clientset
		clientset, err = kubernetes.NewForConfig(config)
		if err != nil {
			log.Fatalf("Unable to build client %s", err)
		}
	}

	log.Infof("Using Namespace: %s", *podNamespace)

	podListWatcher := cache.NewListWatchFromClient(clientset.Core().RESTClient(), "pods",
		*podNamespace, fields.Everything())

	queue := workqueue.NewRateLimitingQueue(workqueue.DefaultControllerRateLimiter())

	indexer, informer := cache.NewIndexerInformer(podListWatcher, &v1.Pod{}, 0, cache.ResourceEventHandlerFuncs{
		AddFunc: func(obj interface{}) {
			key, err := cache.MetaNamespaceKeyFunc(obj)
			if err == nil {
				if che.IsChePod(obj) {
					log.Infof("Adding Pod %s to queue", key)
					queue.Add(key)
				}
			}
		},
		UpdateFunc: func(obj, newObj interface{}) {
			key, err := cache.MetaNamespaceKeyFunc(newObj)
			if err == nil {
				if che.IsChePod(newObj) {
					log.Infof("Updating Pod %s to queue", key)
					queue.Add(key)
				}
			}
		},
		DeleteFunc: func(obj interface{}) {
			key, err := cache.DeletionHandlingMetaNamespaceKeyFunc(obj)
			if err == nil {
				log.Infof("Deleteing Pod %s from queue", key)
				queue.Add(key)
			}
		},
	}, cache.Indexers{})

	//create controller
	controller := che.NewCheController(indexer, informer, queue, *cheEndpointURI, *newStackURL, *incluster)

	indexer.Add(&v1.Pod{
		ObjectMeta: meta_v1.ObjectMeta{
			Namespace: *podNamespace,
			Labels: map[string]string{
				"deploymentconfig": "che",
			},
		},
	})
	stopCh := make(chan struct{})
	defer close(stopCh)
	go controller.Run(1, stopCh)
	select {}
}

//defaultNamespaceFromConfig detect the namespace from currentContext
func defaultNamespaceFromConfig(kubeconfig *string) string {
	config, err := clientcmd.LoadFromFile(*kubeconfig)
	if err != nil {
		log.Errorf("Unable to get NS from context of config %s \n", err)
	}
	return strings.Split(config.CurrentContext, "/")[0]
}