go/vt/worker/status.go

// Copyright 2013, Google Inc. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package worker

import (
	"fmt"
	"html/template"
	"net/http"
	"strings"

	"github.com/youtube/vitess/go/acl"
	"github.com/youtube/vitess/go/vt/servenv"
)

const workerStatusPartHTML = servenv.JQueryIncludes + `
<script type="text/javascript">

$(function() {
    getStatus();
});

function getStatus() {
    $('div#status').load('/status');
    setTimeout("getStatus()",10000);
}

</script>
<div id="status"></div>
`

const workerStatusHTML = `
<html>
<head>
<title>Worker Status</title>
</head>
<body>
{{if .Status}}
  <h2>Worker status:</h2>
  <blockquote>
    {{.Status}}
  </blockquote>
  <h2>Worker logs:</h2>
  <blockquote>
    {{.Logs}}
  </blockquote>
  {{if .Done}}
  <p><a href="/reset">Reset Job</a></p>
  {{else}}
  <p><a href="/cancel">Cancel Job</a></p>
  {{end}}
{{else}}
  <p>This worker is idle.</p>
  <p><a href="/">Toplevel Menu</a></p>
{{end}}
</body>
</html>
`

// InitStatusHandling installs webserver handlers for global actions like /status, /reset and /cancel.
func (wi *Instance) InitStatusHandling() {
	// code to serve /status
	workerTemplate := mustParseTemplate("worker", workerStatusHTML)
	http.HandleFunc("/status", func(w http.ResponseWriter, r *http.Request) {
		if err := acl.CheckAccessHTTP(r, acl.ADMIN); err != nil {
			acl.SendError(w, err)
			return
		}

		wi.currentWorkerMutex.Lock()
		wrk := wi.currentWorker
		logger := wi.currentMemoryLogger
		ctx := wi.currentContext
		err := wi.lastRunError
		stopTime := wi.lastRunStopTime
		wi.currentWorkerMutex.Unlock()

		data := make(map[string]interface{})
		if wrk != nil {
			status := template.HTML("Current worker:<br>\n") + wrk.StatusAsHTML()
			if ctx == nil {
				data["Done"] = true
				if err != nil {
					status += template.HTML(fmt.Sprintf("<br>\nEnded with an error: %v<br>\n", err))
				}
				status += template.HTML(fmt.Sprintf("<br>\n<b>End Time:</b> %v<br>\n", stopTime))
			}
			data["Status"] = status
			if logger != nil {
				data["Logs"] = template.HTML(strings.Replace(logger.String(), "\n", "</br>\n", -1))
			} else {
				data["Logs"] = template.HTML("See console for logs</br>\n")
			}
		}
		executeTemplate(w, workerTemplate, data)
	})

	// add the section in status that does auto-refresh of status div
	servenv.AddStatusPart("Worker Status", workerStatusPartHTML, func() interface{} {
		return nil
	})

	// reset handler
	http.HandleFunc("/reset", func(w http.ResponseWriter, r *http.Request) {
		if err := acl.CheckAccessHTTP(r, acl.ADMIN); err != nil {
			acl.SendError(w, err)
			return
		}

		if err := wi.Reset(); err != nil {
			httpError(w, err.Error(), nil)
		} else {
			// No worker currently running, we go to the menu.
			http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
		}
	})

	// cancel handler
	http.HandleFunc("/cancel", func(w http.ResponseWriter, r *http.Request) {
		if err := acl.CheckAccessHTTP(r, acl.ADMIN); err != nil {
			acl.SendError(w, err)
			return
		}

		if wi.Cancel() {
			// We canceled the running worker. Go back to the status page.
			http.Redirect(w, r, servenv.StatusURLPath(), http.StatusTemporaryRedirect)
		} else {
			// No worker, or not running, we go to the menu.
			http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
		}
	})
}