http to k8s deployment patch. gorilla + k8s go client. For local run set KUBECONFIG path to config file

main.go

package main

import (
	"flag"
	"fmt"

	"encoding/json"
	"github.com/gorilla/mux"
	"github.com/gorilla/handlers"
	"io"
	"io/ioutil"
	"k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/types"
	"k8s.io/client-go/kubernetes"
	v1api "k8s.io/client-go/pkg/api/v1"
	_ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
	"k8s.io/client-go/rest"
	"k8s.io/client-go/tools/clientcmd"
	"log"
	"net/http"
	"os"
)

type DeploySpec struct {
	Name          string `json:"name"`
	ContainerName string `json:"container_name"`
	ImageName     string `json:"image_name"`
	ImageTag      string `json:"image_tag"`
	Namespace     string `json:"namespace"`
}

var client = create_client()

func print_image(podspec v1api.PodSpec) {
	for _, container := range podspec.Containers {
		fmt.Printf("Deployment is %s \n", container.Image)
	}
}

func deploy(spec DeploySpec, clientset *kubernetes.Clientset) {
	fmt.Println("Deploying ", spec.Name)
	deployment, err := clientset.ExtensionsV1beta1().Deployments(spec.Namespace).Get(spec.Name, v1.GetOptions{})
	if err != nil {
		panic(err.Error())
	}
	print_image(deployment.Spec.Template.Spec)

	format := `{"spec":{"template":{"spec":{"containers":[{"name":"%s","image":"%s:%s" }]}}}}`
	patch := fmt.Sprintf(format,
		spec.ContainerName, spec.ImageName, spec.ImageTag)
	deployment_new, err := clientset.ExtensionsV1beta1().Deployments(spec.Namespace).Patch(
		spec.Name,
		types.StrategicMergePatchType,
		[]byte(patch))
	if err != nil {
		panic(err.Error())
	}
	print_image(deployment_new.Spec.Template.Spec)
}

func buildConfig(kubeconfig string) (*rest.Config, error) {
	if kubeconfig != "" {
		return clientcmd.BuildConfigFromFlags("", kubeconfig)
	}
	return rest.InClusterConfig()
}

func create_client() *kubernetes.Clientset {
	config_path := os.Getenv("KUBECONFIG")
	kubeconfig := flag.String("kubeconfig", config_path, "absolute path to the kubeconfig file")
	flag.Parse()
	config, err := buildConfig(*kubeconfig)
	if err != nil {
		panic(err)
	}

	// creates the clientset
	clientset, err := kubernetes.NewForConfig(config)
	if err != nil {
		panic(err.Error())
	}
	return clientset

}

func get_body(httpbody io.ReadCloser) []byte {
	body, err := ioutil.ReadAll(io.LimitReader(httpbody, 1048576))
	if err != nil {
		panic(err)
	}
	if err := httpbody.Close(); err != nil {
		panic(err)
	}
	return body
}

func check_auth(token string)  {
	log.Print(token)
}

func Handler(w http.ResponseWriter, r *http.Request) {
	var ds DeploySpec
	auth := r.Header.Get("Authorization")
	if auth == "" {
		http.Error(w, "Use Google Bearer Authorization", 401)
		return
	}
	check_auth(auth)

	if r.Body == nil {
		http.Error(w, "Please send a request body", 400)
		return
	}
	body := get_body(r.Body)

	if err := json.Unmarshal(body, &ds); err != nil {
		http.Error(w, err.Error(), 400)
		return
	}

	deploy(ds, client)
	if err := json.NewEncoder(w).Encode(ds); err != nil {
		panic(err)
	}
}

func main() {
	router := mux.NewRouter().StrictSlash(true)
	router.HandleFunc("/", Handler)
	loggedRouter := handlers.CombinedLoggingHandler(os.Stdout, router)
	log.Print("Starting http server")
	log.Fatal(http.ListenAndServe(":18080", loggedRouter))
}