taion809/main.go

## main.go
package main

import (
	"context"
	"encoding/json"
	"fmt"
	"log"
	"net/http"

	"github.com/go-chi/chi"
	"github.com/go-chi/chi/middleware"
	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/watch"
	"k8s.io/client-go/kubernetes"
	"k8s.io/client-go/tools/clientcmd"
)

var clientset *kubernetes.Clientset

func generateK8sEvents(ctx context.Context) (watch.Interface, error) {
	events, err := clientset.CoreV1().Events("").Watch(ctx, v1.ListOptions{})
	if err != nil {
		return nil, err
	}

	return events, nil
}

func index(w http.ResponseWriter, r *http.Request) {
	w.WriteHeader(http.StatusOK)
	w.Write([]byte(indexTmpl))
}

func events(w http.ResponseWriter, r *http.Request) {
	flush, ok := w.(http.Flusher)
	if !ok {
		log.Println("Error casting ResponseWriter to Flusher, SSE is not supported")
		w.WriteHeader(http.StatusInternalServerError)
		return
	}

	events, err := generateK8sEvents(r.Context())
	if err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		w.Write([]byte(err.Error()))
		return
	}

	defer events.Stop()

	w.Header().Set("Content-Type", "text/event-stream")

	card := fmt.Sprintf(cardTemplate, "Initial", "initial k8s event", "")
	fmt.Fprintf(w, "data: %s\n\n", card)
	flush.Flush()

	for event := range events.ResultChan() {
		log.Println("Event from events api", event.Type)

		// fuck this stupid api
		b, err := json.Marshal(event)
		if err != nil {
			log.Println("Failed to write to stream", err)
			break
		}

		var extract map[string]interface{}
		err = json.Unmarshal(b, &extract)
		if err != nil {
			log.Println("Failed to write to stream", err)
			break
		}

		obj := extract["Object"].(map[string]interface{})
		card = fmt.Sprintf(cardTemplate, obj["reason"], obj["message"], obj["lastTimestamp"])
		fmt.Fprintf(w, "data: %v\n\n", card)

		flush.Flush()
	}
}

func main() {
	// uses the current context in kubeconfig
	// path-to-kubeconfig -- for example, /root/.kube/config
	config, err := clientcmd.BuildConfigFromFlags("", "/home/nicholas/.kube/config")
	if err != nil {
		log.Fatalln("Unable to open k8s kube config", err)
	}

	// creates the clientset
	clientset, err = kubernetes.NewForConfig(config)
	if err != nil {
		log.Fatalln("Unable to create k8s clientset", err)
	}

	r := chi.NewRouter()
	r.Use(middleware.Logger)
	r.Get("/", index)
	r.Get("/events", events)

	fmt.Println("starting server :3000")
	if err := http.ListenAndServe(":3000", r); err != nil {
		log.Fatalln(err)
	}
}

## tmpl.go
package main

var indexTmpl = `
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Hello Everybody!</title>
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bulma@0.9.4/css/bulma.min.css">
	<script src="https://unpkg.com/htmx.org@1.9.8" integrity="sha384-rgjA7mptc2ETQqXoYC3/zJvkU7K/aP44Y+z7xQuJiVnB/422P/Ak+F/AqFR7E4Wr" crossorigin="anonymous"></script>
  	<script src="https://unpkg.com/htmx.org/dist/ext/sse.js"></script>
  </head>
  <body>
  <section class="section">
    <div class="container">
      <h1 class="title">
        Hello World
      </h1>
	  <div id="eventStream">
	  	<p>waiting...</p>
	  </div>
	  <div hx-ext="sse" sse-connect="/events" sse-swap="message" hx-swap="afterbegin" hx-target="#eventStream">
		Waiting for k8s events...
  	  </div>
    </div>
  </section>

  </body>
</html>
`

var cardTemplate = `<div class="card" style="margin-bottom:10px"><header class="card-header"><p class="card-header-title">%s</p></header><div class="card-content"><div class="content">%s<br><span>Received: <strong>%s</strong></span></div></div>`
	package main

	import (
	"context"
	"encoding/json"
	"fmt"
	"log"
	"net/http"

	"github.com/go-chi/chi"
	"github.com/go-chi/chi/middleware"
	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/watch"
	"k8s.io/client-go/kubernetes"
	"k8s.io/client-go/tools/clientcmd"
	)

	var clientset *kubernetes.Clientset

	func generateK8sEvents(ctx context.Context) (watch.Interface, error) {
	events, err := clientset.CoreV1().Events("").Watch(ctx, v1.ListOptions{})
	if err != nil {
	return nil, err
	}

	return events, nil
	}

	func index(w http.ResponseWriter, r *http.Request) {
	w.WriteHeader(http.StatusOK)
	w.Write([]byte(indexTmpl))
	}

	func events(w http.ResponseWriter, r *http.Request) {
	flush, ok := w.(http.Flusher)
	if !ok {
	log.Println("Error casting ResponseWriter to Flusher, SSE is not supported")
	w.WriteHeader(http.StatusInternalServerError)
	return
	}

	events, err := generateK8sEvents(r.Context())
	if err != nil {
	w.WriteHeader(http.StatusInternalServerError)
	w.Write([]byte(err.Error()))
	return
	}

	defer events.Stop()

	w.Header().Set("Content-Type", "text/event-stream")

	card := fmt.Sprintf(cardTemplate, "Initial", "initial k8s event", "")
	fmt.Fprintf(w, "data: %s\n\n", card)
	flush.Flush()

	for event := range events.ResultChan() {
	log.Println("Event from events api", event.Type)

	// fuck this stupid api
	b, err := json.Marshal(event)
	if err != nil {
	log.Println("Failed to write to stream", err)
	break
	}

	var extract map[string]interface{}
	err = json.Unmarshal(b, &extract)
	if err != nil {
	log.Println("Failed to write to stream", err)
	break
	}

	obj := extract["Object"].(map[string]interface{})
	card = fmt.Sprintf(cardTemplate, obj["reason"], obj["message"], obj["lastTimestamp"])
	fmt.Fprintf(w, "data: %v\n\n", card)

	flush.Flush()
	}
	}

	func main() {
	// uses the current context in kubeconfig
	// path-to-kubeconfig -- for example, /root/.kube/config
	config, err := clientcmd.BuildConfigFromFlags("", "/home/nicholas/.kube/config")
	if err != nil {
	log.Fatalln("Unable to open k8s kube config", err)
	}

	// creates the clientset
	clientset, err = kubernetes.NewForConfig(config)
	if err != nil {
	log.Fatalln("Unable to create k8s clientset", err)
	}

	r := chi.NewRouter()
	r.Use(middleware.Logger)
	r.Get("/", index)
	r.Get("/events", events)

	fmt.Println("starting server :3000")
	if err := http.ListenAndServe(":3000", r); err != nil {
	log.Fatalln(err)
	}
	}
	package main

	var indexTmpl = `
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8">
	<meta name="viewport" content="width=device-width, initial-scale=1">
	<title>Hello Everybody!</title>
	<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bulma@0.9.4/css/bulma.min.css">
	<script src="https://unpkg.com/htmx.org@1.9.8" integrity="sha384-rgjA7mptc2ETQqXoYC3/zJvkU7K/aP44Y+z7xQuJiVnB/422P/Ak+F/AqFR7E4Wr" crossorigin="anonymous"></script>
	<script src="https://unpkg.com/htmx.org/dist/ext/sse.js"></script>
	</head>
	<body>
	<section class="section">
	<div class="container">
	<h1 class="title">
	Hello World
	</h1>
	<div id="eventStream">
	<p>waiting...</p>
	</div>
	<div hx-ext="sse" sse-connect="/events" sse-swap="message" hx-swap="afterbegin" hx-target="#eventStream">
	Waiting for k8s events...
	</div>
	</div>
	</section>

	</body>
	</html>
	`

	var cardTemplate = `<div class="card" style="margin-bottom:10px"><header class="card-header"><p class="card-header-title">%s</p></header><div class="card-content"><div class="content">%s<br><span>Received: <strong>%s</strong></span></div></div>`