webui.go

     1  // Copyright 2017 Google Inc. All Rights Reserved.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package driver
    16  
    17  import (
    18  	"bytes"
    19  	"fmt"
    20  	"html/template"
    21  	"net"
    22  	"net/http"
    23  	gourl "net/url"
    24  	"os"
    25  	"os/exec"
    26  	"strconv"
    27  	"strings"
    28  	"time"
    29  
    30  	"github.com/google/pprof/internal/graph"
    31  	"github.com/google/pprof/internal/plugin"
    32  	"github.com/google/pprof/internal/report"
    33  	"github.com/google/pprof/profile"
    34  )
    35  
    36  // webInterface holds the state needed for serving a browser based interface.
    37  type webInterface struct {
    38  	prof         *profile.Profile
    39  	options      *plugin.Options
    40  	help         map[string]string
    41  	templates    *template.Template
    42  	settingsFile string
    43  }
    44  
    45  func makeWebInterface(p *profile.Profile, opt *plugin.Options) (*webInterface, error) {
    46  	settingsFile, err := settingsFileName()
    47  	if err != nil {
    48  		return nil, err
    49  	}
    50  	templates := template.New("templategroup")
    51  	addTemplates(templates)
    52  	report.AddSourceTemplates(templates)
    53  	return &webInterface{
    54  		prof:         p,
    55  		options:      opt,
    56  		help:         make(map[string]string),
    57  		templates:    templates,
    58  		settingsFile: settingsFile,
    59  	}, nil
    60  }
    61  
    62  // maxEntries is the maximum number of entries to print for text interfaces.
    63  const maxEntries = 50
    64  
    65  // errorCatcher is a UI that captures errors for reporting to the browser.
    66  type errorCatcher struct {
    67  	plugin.UI
    68  	errors []string
    69  }
    70  
    71  func (ec *errorCatcher) PrintErr(args ...interface{}) {
    72  	ec.errors = append(ec.errors, strings.TrimSuffix(fmt.Sprintln(args...), "\n"))
    73  	ec.UI.PrintErr(args...)
    74  }
    75  
    76  // webArgs contains arguments passed to templates in webhtml.go.
    77  type webArgs struct {
    78  	Title       string
    79  	Errors      []string
    80  	Total       int64
    81  	SampleTypes []string
    82  	Legend      []string
    83  	Help        map[string]string
    84  	Nodes       []string
    85  	HTMLBody    template.HTML
    86  	TextBody    string
    87  	Top         []report.TextItem
    88  	FlameGraph  template.JS
    89  	Configs     []configMenuEntry
    90  }
    91  
    92  func serveWebInterface(hostport string, p *profile.Profile, o *plugin.Options, disableBrowser bool) error {
    93  	host, port, err := getHostAndPort(hostport)
    94  	if err != nil {
    95  		return err
    96  	}
    97  	interactiveMode = true
    98  	ui, err := makeWebInterface(p, o)
    99  	if err != nil {
   100  		return err
   101  	}
   102  	for n, c := range pprofCommands {
   103  		ui.help[n] = c.description
   104  	}
   105  	for n, help := range configHelp {
   106  		ui.help[n] = help
   107  	}
   108  	ui.help["details"] = "Show information about the profile and this view"
   109  	ui.help["graph"] = "Display profile as a directed graph"
   110  	ui.help["reset"] = "Show the entire profile"
   111  	ui.help["save_config"] = "Save current settings"
   112  
   113  	server := o.HTTPServer
   114  	if server == nil {
   115  		server = defaultWebServer
   116  	}
   117  	args := &plugin.HTTPServerArgs{
   118  		Hostport: net.JoinHostPort(host, strconv.Itoa(port)),
   119  		Host:     host,
   120  		Port:     port,
   121  		Handlers: map[string]http.Handler{
   122  			"/":             http.HandlerFunc(ui.dot),
   123  			"/top":          http.HandlerFunc(ui.top),
   124  			"/disasm":       http.HandlerFunc(ui.disasm),
   125  			"/source":       http.HandlerFunc(ui.source),
   126  			"/peek":         http.HandlerFunc(ui.peek),
   127  			"/flamegraph":   http.HandlerFunc(ui.flamegraph),
   128  			"/saveconfig":   http.HandlerFunc(ui.saveConfig),
   129  			"/deleteconfig": http.HandlerFunc(ui.deleteConfig),
   130  			"/download": http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
   131  				w.Header().Set("Content-Type", "application/vnd.google.protobuf+gzip")
   132  				w.Header().Set("Content-Disposition", "attachment;filename=profile.pb.gz")
   133  				p.Write(w)
   134  			}),
   135  		},
   136  	}
   137  
   138  	url := "http://" + args.Hostport
   139  
   140  	o.UI.Print("Serving web UI on ", url)
   141  
   142  	if o.UI.WantBrowser() && !disableBrowser {
   143  		go openBrowser(url, o)
   144  	}
   145  	return server(args)
   146  }
   147  
   148  func getHostAndPort(hostport string) (string, int, error) {
   149  	host, portStr, err := net.SplitHostPort(hostport)
   150  	if err != nil {
   151  		return "", 0, fmt.Errorf("could not split http address: %v", err)
   152  	}
   153  	if host == "" {
   154  		host = "localhost"
   155  	}
   156  	var port int
   157  	if portStr == "" {
   158  		ln, err := net.Listen("tcp", net.JoinHostPort(host, "0"))
   159  		if err != nil {
   160  			return "", 0, fmt.Errorf("could not generate random port: %v", err)
   161  		}
   162  		port = ln.Addr().(*net.TCPAddr).Port
   163  		err = ln.Close()
   164  		if err != nil {
   165  			return "", 0, fmt.Errorf("could not generate random port: %v", err)
   166  		}
   167  	} else {
   168  		port, err = strconv.Atoi(portStr)
   169  		if err != nil {
   170  			return "", 0, fmt.Errorf("invalid port number: %v", err)
   171  		}
   172  	}
   173  	return host, port, nil
   174  }
   175  func defaultWebServer(args *plugin.HTTPServerArgs) error {
   176  	ln, err := net.Listen("tcp", args.Hostport)
   177  	if err != nil {
   178  		return err
   179  	}
   180  	isLocal := isLocalhost(args.Host)
   181  	handler := http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
   182  		if isLocal {
   183  			// Only allow local clients
   184  			host, _, err := net.SplitHostPort(req.RemoteAddr)
   185  			if err != nil || !isLocalhost(host) {
   186  				http.Error(w, "permission denied", http.StatusForbidden)
   187  				return
   188  			}
   189  		}
   190  		h := args.Handlers[req.URL.Path]
   191  		if h == nil {
   192  			// Fall back to default behavior
   193  			h = http.DefaultServeMux
   194  		}
   195  		h.ServeHTTP(w, req)
   196  	})
   197  
   198  	// We serve the ui at /ui/ and redirect there from the root. This is done
   199  	// to surface any problems with serving the ui at a non-root early. See:
   200  	//
   201  	// https://github.com/google/pprof/pull/348
   202  	mux := http.NewServeMux()
   203  	mux.Handle("/ui/", http.StripPrefix("/ui", handler))
   204  	mux.Handle("/", redirectWithQuery("/ui"))
   205  	s := &http.Server{Handler: mux}
   206  	return s.Serve(ln)
   207  }
   208  
   209  func redirectWithQuery(path string) http.HandlerFunc {
   210  	return func(w http.ResponseWriter, r *http.Request) {
   211  		pathWithQuery := &gourl.URL{Path: path, RawQuery: r.URL.RawQuery}
   212  		http.Redirect(w, r, pathWithQuery.String(), http.StatusTemporaryRedirect)
   213  	}
   214  }
   215  
   216  func isLocalhost(host string) bool {
   217  	for _, v := range []string{"localhost", "127.0.0.1", "[::1]", "::1"} {
   218  		if host == v {
   219  			return true
   220  		}
   221  	}
   222  	return false
   223  }
   224  
   225  func openBrowser(url string, o *plugin.Options) {
   226  	// Construct URL.
   227  	baseURL, _ := gourl.Parse(url)
   228  	current := currentConfig()
   229  	u, _ := current.makeURL(*baseURL)
   230  
   231  	// Give server a little time to get ready.
   232  	time.Sleep(time.Millisecond * 500)
   233  
   234  	for _, b := range browsers() {
   235  		args := strings.Split(b, " ")
   236  		if len(args) == 0 {
   237  			continue
   238  		}
   239  		viewer := exec.Command(args[0], append(args[1:], u.String())...)
   240  		viewer.Stderr = os.Stderr
   241  		if err := viewer.Start(); err == nil {
   242  			return
   243  		}
   244  	}
   245  	// No visualizer succeeded, so just print URL.
   246  	o.UI.PrintErr(u.String())
   247  }
   248  
   249  // makeReport generates a report for the specified command.
   250  // If configEditor is not null, it is used to edit the config used for the report.
   251  func (ui *webInterface) makeReport(w http.ResponseWriter, req *http.Request,
   252  	cmd []string, configEditor func(*config)) (*report.Report, []string) {
   253  	cfg := currentConfig()
   254  	if err := cfg.applyURL(req.URL.Query()); err != nil {
   255  		http.Error(w, err.Error(), http.StatusBadRequest)
   256  		ui.options.UI.PrintErr(err)
   257  		return nil, nil
   258  	}
   259  	if configEditor != nil {
   260  		configEditor(&cfg)
   261  	}
   262  	catcher := &errorCatcher{UI: ui.options.UI}
   263  	options := *ui.options
   264  	options.UI = catcher
   265  	_, rpt, err := generateRawReport(ui.prof, cmd, cfg, &options)
   266  	if err != nil {
   267  		http.Error(w, err.Error(), http.StatusBadRequest)
   268  		ui.options.UI.PrintErr(err)
   269  		return nil, nil
   270  	}
   271  	return rpt, catcher.errors
   272  }
   273  
   274  // render generates html using the named template based on the contents of data.
   275  func (ui *webInterface) render(w http.ResponseWriter, req *http.Request, tmpl string,
   276  	rpt *report.Report, errList, legend []string, data webArgs) {
   277  	file := getFromLegend(legend, "File: ", "unknown")
   278  	profile := getFromLegend(legend, "Type: ", "unknown")
   279  	data.Title = file + " " + profile
   280  	data.Errors = errList
   281  	data.Total = rpt.Total()
   282  	data.SampleTypes = sampleTypes(ui.prof)
   283  	data.Legend = legend
   284  	data.Help = ui.help
   285  	data.Configs = configMenu(ui.settingsFile, *req.URL)
   286  
   287  	html := &bytes.Buffer{}
   288  	if err := ui.templates.ExecuteTemplate(html, tmpl, data); err != nil {
   289  		http.Error(w, "internal template error", http.StatusInternalServerError)
   290  		ui.options.UI.PrintErr(err)
   291  		return
   292  	}
   293  	w.Header().Set("Content-Type", "text/html")
   294  	w.Write(html.Bytes())
   295  }
   296  
   297  // dot generates a web page containing an svg diagram.
   298  func (ui *webInterface) dot(w http.ResponseWriter, req *http.Request) {
   299  	rpt, errList := ui.makeReport(w, req, []string{"svg"}, nil)
   300  	if rpt == nil {
   301  		return // error already reported
   302  	}
   303  
   304  	// Generate dot graph.
   305  	g, config := report.GetDOT(rpt)
   306  	legend := config.Labels
   307  	config.Labels = nil
   308  	dot := &bytes.Buffer{}
   309  	graph.ComposeDot(dot, g, &graph.DotAttributes{}, config)
   310  
   311  	// Convert to svg.
   312  	svg, err := dotToSvg(dot.Bytes())
   313  	if err != nil {
   314  		http.Error(w, "Could not execute dot; may need to install graphviz.",
   315  			http.StatusNotImplemented)
   316  		ui.options.UI.PrintErr("Failed to execute dot. Is Graphviz installed?\n", err)
   317  		return
   318  	}
   319  
   320  	// Get all node names into an array.
   321  	nodes := []string{""} // dot starts with node numbered 1
   322  	for _, n := range g.Nodes {
   323  		nodes = append(nodes, n.Info.Name)
   324  	}
   325  
   326  	ui.render(w, req, "graph", rpt, errList, legend, webArgs{
   327  		HTMLBody: template.HTML(string(svg)),
   328  		Nodes:    nodes,
   329  	})
   330  }
   331  
   332  func dotToSvg(dot []byte) ([]byte, error) {
   333  	cmd := exec.Command("dot", "-Tsvg")
   334  	out := &bytes.Buffer{}
   335  	cmd.Stdin, cmd.Stdout, cmd.Stderr = bytes.NewBuffer(dot), out, os.Stderr
   336  	if err := cmd.Run(); err != nil {
   337  		return nil, err
   338  	}
   339  
   340  	// Fix dot bug related to unquoted ampersands.
   341  	svg := bytes.Replace(out.Bytes(), []byte("&;"), []byte("&amp;;"), -1)
   342  
   343  	// Cleanup for embedding by dropping stuff before the <svg> start.
   344  	if pos := bytes.Index(svg, []byte("<svg")); pos >= 0 {
   345  		svg = svg[pos:]
   346  	}
   347  	return svg, nil
   348  }
   349  
   350  func (ui *webInterface) top(w http.ResponseWriter, req *http.Request) {
   351  	rpt, errList := ui.makeReport(w, req, []string{"top"}, func(cfg *config) {
   352  		cfg.NodeCount = 500
   353  	})
   354  	if rpt == nil {
   355  		return // error already reported
   356  	}
   357  	top, legend := report.TextItems(rpt)
   358  	var nodes []string
   359  	for _, item := range top {
   360  		nodes = append(nodes, item.Name)
   361  	}
   362  
   363  	ui.render(w, req, "top", rpt, errList, legend, webArgs{
   364  		Top:   top,
   365  		Nodes: nodes,
   366  	})
   367  }
   368  
   369  // disasm generates a web page containing disassembly.
   370  func (ui *webInterface) disasm(w http.ResponseWriter, req *http.Request) {
   371  	args := []string{"disasm", req.URL.Query().Get("f")}
   372  	rpt, errList := ui.makeReport(w, req, args, nil)
   373  	if rpt == nil {
   374  		return // error already reported
   375  	}
   376  
   377  	out := &bytes.Buffer{}
   378  	if err := report.PrintAssembly(out, rpt, ui.options.Obj, maxEntries); err != nil {
   379  		http.Error(w, err.Error(), http.StatusBadRequest)
   380  		ui.options.UI.PrintErr(err)
   381  		return
   382  	}
   383  
   384  	legend := report.ProfileLabels(rpt)
   385  	ui.render(w, req, "plaintext", rpt, errList, legend, webArgs{
   386  		TextBody: out.String(),
   387  	})
   388  
   389  }
   390  
   391  // source generates a web page containing source code annotated with profile
   392  // data.
   393  func (ui *webInterface) source(w http.ResponseWriter, req *http.Request) {
   394  	args := []string{"weblist", req.URL.Query().Get("f")}
   395  	rpt, errList := ui.makeReport(w, req, args, nil)
   396  	if rpt == nil {
   397  		return // error already reported
   398  	}
   399  
   400  	// Generate source listing.
   401  	var body bytes.Buffer
   402  	if err := report.PrintWebList(&body, rpt, ui.options.Obj, maxEntries); err != nil {
   403  		http.Error(w, err.Error(), http.StatusBadRequest)
   404  		ui.options.UI.PrintErr(err)
   405  		return
   406  	}
   407  
   408  	legend := report.ProfileLabels(rpt)
   409  	ui.render(w, req, "sourcelisting", rpt, errList, legend, webArgs{
   410  		HTMLBody: template.HTML(body.String()),
   411  	})
   412  }
   413  
   414  // peek generates a web page listing callers/callers.
   415  func (ui *webInterface) peek(w http.ResponseWriter, req *http.Request) {
   416  	args := []string{"peek", req.URL.Query().Get("f")}
   417  	rpt, errList := ui.makeReport(w, req, args, func(cfg *config) {
   418  		cfg.Granularity = "lines"
   419  	})
   420  	if rpt == nil {
   421  		return // error already reported
   422  	}
   423  
   424  	out := &bytes.Buffer{}
   425  	if err := report.Generate(out, rpt, ui.options.Obj); err != nil {
   426  		http.Error(w, err.Error(), http.StatusBadRequest)
   427  		ui.options.UI.PrintErr(err)
   428  		return
   429  	}
   430  
   431  	legend := report.ProfileLabels(rpt)
   432  	ui.render(w, req, "plaintext", rpt, errList, legend, webArgs{
   433  		TextBody: out.String(),
   434  	})
   435  }
   436  
   437  // saveConfig saves URL configuration.
   438  func (ui *webInterface) saveConfig(w http.ResponseWriter, req *http.Request) {
   439  	if err := setConfig(ui.settingsFile, *req.URL); err != nil {
   440  		http.Error(w, err.Error(), http.StatusBadRequest)
   441  		ui.options.UI.PrintErr(err)
   442  		return
   443  	}
   444  }
   445  
   446  // deleteConfig deletes a configuration.
   447  func (ui *webInterface) deleteConfig(w http.ResponseWriter, req *http.Request) {
   448  	name := req.URL.Query().Get("config")
   449  	if err := removeConfig(ui.settingsFile, name); err != nil {
   450  		http.Error(w, err.Error(), http.StatusBadRequest)
   451  		ui.options.UI.PrintErr(err)
   452  		return
   453  	}
   454  }
   455  
   456  // getFromLegend returns the suffix of an entry in legend that starts
   457  // with param.  It returns def if no such entry is found.
   458  func getFromLegend(legend []string, param, def string) string {
   459  	for _, s := range legend {
   460  		if strings.HasPrefix(s, param) {
   461  			return s[len(param):]
   462  		}
   463  	}
   464  	return def
   465  }
   466
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