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  	"io"
    22  	"maps"
    23  	"net"
    24  	"net/http"
    25  	gourl "net/url"
    26  	"os"
    27  	"os/exec"
    28  	"slices"
    29  	"strconv"
    30  	"strings"
    31  	"time"
    32  
    33  	"github.com/google/pprof/internal/graph"
    34  	"github.com/google/pprof/internal/measurement"
    35  	"github.com/google/pprof/internal/plugin"
    36  	"github.com/google/pprof/internal/report"
    37  	"github.com/google/pprof/profile"
    38  )
    39  
    40  // webInterface holds the state needed for serving a browser based interface.
    41  type webInterface struct {
    42  	prof         *profile.Profile
    43  	copier       profileCopier
    44  	options      *plugin.Options
    45  	help         map[string]string
    46  	settingsFile string
    47  }
    48  
    49  func makeWebInterface(p *profile.Profile, copier profileCopier, opt *plugin.Options) (*webInterface, error) {
    50  	settingsFile, err := settingsFileName()
    51  	if err != nil {
    52  		return nil, err
    53  	}
    54  	return &webInterface{
    55  		prof:         p,
    56  		copier:       copier,
    57  		options:      opt,
    58  		help:         make(map[string]string),
    59  		settingsFile: settingsFile,
    60  	}, nil
    61  }
    62  
    63  // maxEntries is the maximum number of entries to print for text interfaces.
    64  const maxEntries = 50
    65  
    66  // errorCatcher is a UI that captures errors for reporting to the browser.
    67  type errorCatcher struct {
    68  	plugin.UI
    69  	errors []string
    70  }
    71  
    72  func (ec *errorCatcher) PrintErr(args ...interface{}) {
    73  	ec.errors = append(ec.errors, strings.TrimSuffix(fmt.Sprintln(args...), "\n"))
    74  	ec.UI.PrintErr(args...)
    75  }
    76  
    77  // webArgs contains arguments passed to templates in webhtml.go.
    78  type webArgs struct {
    79  	Title       string
    80  	Errors      []string
    81  	Total       int64
    82  	SampleTypes []string
    83  	Legend      []string
    84  	DocURL      string
    85  	Standalone  bool // True for command-line generation of HTML
    86  	Help        map[string]string
    87  	Nodes       []string
    88  	HTMLBody    template.HTML
    89  	TextBody    string
    90  	Top         []report.TextItem
    91  	Listing     report.WebListData
    92  	FlameGraph  template.JS
    93  	Stacks      template.JS
    94  	Configs     []configMenuEntry
    95  	UnitDefs    []measurement.UnitType
    96  }
    97  
    98  func serveWebInterface(hostport string, p *profile.Profile, o *plugin.Options, disableBrowser bool) error {
    99  	host, port, err := getHostAndPort(hostport)
   100  	if err != nil {
   101  		return err
   102  	}
   103  	interactiveMode = true
   104  	copier := makeProfileCopier(p)
   105  	ui, err := makeWebInterface(p, copier, o)
   106  	if err != nil {
   107  		return err
   108  	}
   109  	for n, c := range pprofCommands {
   110  		ui.help[n] = c.description
   111  	}
   112  	maps.Copy(ui.help, configHelp)
   113  	ui.help["details"] = "Show information about the profile and this view"
   114  	ui.help["graph"] = "Display profile as a directed graph"
   115  	ui.help["flamegraph"] = "Display profile as a flame graph"
   116  	ui.help["reset"] = "Show the entire profile"
   117  	ui.help["save_config"] = "Save current settings"
   118  
   119  	server := o.HTTPServer
   120  	if server == nil {
   121  		server = defaultWebServer
   122  	}
   123  	args := &plugin.HTTPServerArgs{
   124  		Hostport: net.JoinHostPort(host, strconv.Itoa(port)),
   125  		Host:     host,
   126  		Port:     port,
   127  		Handlers: map[string]http.Handler{
   128  			"/":             redirectWithQuery("flamegraph", http.StatusMovedPermanently),
   129  			"/graph":        http.HandlerFunc(ui.dot),
   130  			"/top":          http.HandlerFunc(ui.top),
   131  			"/disasm":       http.HandlerFunc(ui.disasm),
   132  			"/source":       http.HandlerFunc(ui.source),
   133  			"/peek":         http.HandlerFunc(ui.peek),
   134  			"/flamegraph":   http.HandlerFunc(ui.stackView),
   135  			"/saveconfig":   http.HandlerFunc(ui.saveConfig),
   136  			"/deleteconfig": http.HandlerFunc(ui.deleteConfig),
   137  			"/download": http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
   138  				w.Header().Set("Content-Type", "application/vnd.google.protobuf+gzip")
   139  				w.Header().Set("Content-Disposition", "attachment;filename=profile.pb.gz")
   140  				p.Write(w)
   141  			}),
   142  			// Keep legacy URLs working.
   143  			"/flamegraph2":   redirectWithQuery("flamegraph", http.StatusMovedPermanently),
   144  			"/flamegraphold": redirectWithQuery("flamegraph", http.StatusMovedPermanently),
   145  		},
   146  	}
   147  
   148  	url := "http://" + args.Hostport
   149  
   150  	o.UI.Print("Serving web UI on ", url)
   151  
   152  	if o.UI.WantBrowser() && !disableBrowser {
   153  		go openBrowser(url, o)
   154  	}
   155  	return server(args)
   156  }
   157  
   158  func getHostAndPort(hostport string) (string, int, error) {
   159  	host, portStr, err := net.SplitHostPort(hostport)
   160  	if err != nil {
   161  		return "", 0, fmt.Errorf("could not split http address: %v", err)
   162  	}
   163  	if host == "" {
   164  		host = "localhost"
   165  	}
   166  	var port int
   167  	if portStr == "" {
   168  		ln, err := net.Listen("tcp", net.JoinHostPort(host, "0"))
   169  		if err != nil {
   170  			return "", 0, fmt.Errorf("could not generate random port: %v", err)
   171  		}
   172  		port = ln.Addr().(*net.TCPAddr).Port
   173  		err = ln.Close()
   174  		if err != nil {
   175  			return "", 0, fmt.Errorf("could not generate random port: %v", err)
   176  		}
   177  	} else {
   178  		port, err = strconv.Atoi(portStr)
   179  		if err != nil {
   180  			return "", 0, fmt.Errorf("invalid port number: %v", err)
   181  		}
   182  	}
   183  	return host, port, nil
   184  }
   185  func defaultWebServer(args *plugin.HTTPServerArgs) error {
   186  	ln, err := net.Listen("tcp", args.Hostport)
   187  	if err != nil {
   188  		return err
   189  	}
   190  	isLocal := isLocalhost(args.Host)
   191  	handler := http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
   192  		if isLocal {
   193  			// Only allow local clients
   194  			host, _, err := net.SplitHostPort(req.RemoteAddr)
   195  			if err != nil || !isLocalhost(host) {
   196  				http.Error(w, "permission denied", http.StatusForbidden)
   197  				return
   198  			}
   199  		}
   200  		h := args.Handlers[req.URL.Path]
   201  		if h == nil {
   202  			// Fall back to default behavior
   203  			h = http.DefaultServeMux
   204  		}
   205  		h.ServeHTTP(w, req)
   206  	})
   207  
   208  	// We serve the ui at /ui/ and redirect there from the root. This is done
   209  	// to surface any problems with serving the ui at a non-root early. See:
   210  	//
   211  	// https://github.com/google/pprof/pull/348
   212  	mux := http.NewServeMux()
   213  	mux.Handle("/ui/", http.StripPrefix("/ui", handler))
   214  	mux.Handle("/", redirectWithQuery("/ui", http.StatusTemporaryRedirect))
   215  	s := &http.Server{Handler: mux}
   216  	return s.Serve(ln)
   217  }
   218  
   219  // redirectWithQuery responds with a given redirect code, preserving query
   220  // parameters in the redirect URL. It does not convert relative paths to
   221  // absolute paths like http.Redirect does, so that HTTPServerArgs.Handlers can
   222  // generate relative redirects that work with the external prefixing.
   223  func redirectWithQuery(path string, code int) http.HandlerFunc {
   224  	return func(w http.ResponseWriter, r *http.Request) {
   225  		pathWithQuery := &gourl.URL{Path: path, RawQuery: r.URL.RawQuery}
   226  		w.Header().Set("Location", pathWithQuery.String())
   227  		w.WriteHeader(code)
   228  	}
   229  }
   230  
   231  func isLocalhost(host string) bool {
   232  	return slices.Contains([]string{"localhost", "127.0.0.1", "[::1]", "::1"}, host)
   233  }
   234  
   235  func openBrowser(url string, o *plugin.Options) {
   236  	// Construct URL.
   237  	baseURL, _ := gourl.Parse(url)
   238  	current := currentConfig()
   239  	u, _ := current.makeURL(*baseURL)
   240  
   241  	// Give server a little time to get ready.
   242  	time.Sleep(time.Millisecond * 500)
   243  
   244  	for _, b := range browsers() {
   245  		args := strings.Split(b, " ")
   246  		if len(args) == 0 {
   247  			continue
   248  		}
   249  		viewer := exec.Command(args[0], append(args[1:], u.String())...)
   250  		viewer.Stderr = os.Stderr
   251  		if err := viewer.Start(); err == nil {
   252  			return
   253  		}
   254  	}
   255  	// No visualizer succeeded, so just print URL.
   256  	o.UI.PrintErr(u.String())
   257  }
   258  
   259  // makeReport generates a report for the specified command.
   260  // If configEditor is not null, it is used to edit the config used for the report.
   261  func (ui *webInterface) makeReport(w http.ResponseWriter, req *http.Request,
   262  	cmd []string, configEditor func(*config)) (*report.Report, []string) {
   263  	cfg := currentConfig()
   264  	if err := cfg.applyURL(req.URL.Query()); err != nil {
   265  		http.Error(w, err.Error(), http.StatusBadRequest)
   266  		ui.options.UI.PrintErr(err)
   267  		return nil, nil
   268  	}
   269  	if configEditor != nil {
   270  		configEditor(&cfg)
   271  	}
   272  	catcher := &errorCatcher{UI: ui.options.UI}
   273  	options := *ui.options
   274  	options.UI = catcher
   275  	_, rpt, err := generateRawReport(ui.copier.newCopy(), cmd, cfg, &options)
   276  	if err != nil {
   277  		http.Error(w, err.Error(), http.StatusBadRequest)
   278  		ui.options.UI.PrintErr(err)
   279  		return nil, nil
   280  	}
   281  	return rpt, catcher.errors
   282  }
   283  
   284  // renderHTML generates html using the named template based on the contents of data.
   285  func renderHTML(dst io.Writer, tmpl string, rpt *report.Report, errList, legend []string, data webArgs) error {
   286  	file := getFromLegend(legend, "File: ", "unknown")
   287  	profile := getFromLegend(legend, "Type: ", "unknown")
   288  	data.Title = file + " " + profile
   289  	data.Errors = errList
   290  	data.Total = rpt.Total()
   291  	data.DocURL = rpt.DocURL()
   292  	data.Legend = legend
   293  	return getHTMLTemplates().ExecuteTemplate(dst, tmpl, data)
   294  }
   295  
   296  // render responds with html generated by passing data to the named template.
   297  func (ui *webInterface) render(w http.ResponseWriter, req *http.Request, tmpl string,
   298  	rpt *report.Report, errList, legend []string, data webArgs) {
   299  	data.SampleTypes = sampleTypes(ui.prof)
   300  	data.Help = ui.help
   301  	data.Configs = configMenu(ui.settingsFile, *req.URL)
   302  	html := &bytes.Buffer{}
   303  	if err := renderHTML(html, tmpl, rpt, errList, legend, data); err != nil {
   304  		http.Error(w, "internal template error", http.StatusInternalServerError)
   305  		ui.options.UI.PrintErr(err)
   306  		return
   307  	}
   308  	w.Header().Set("Content-Type", "text/html")
   309  	w.Write(html.Bytes())
   310  }
   311  
   312  // dot generates a web page containing an svg diagram.
   313  func (ui *webInterface) dot(w http.ResponseWriter, req *http.Request) {
   314  	rpt, errList := ui.makeReport(w, req, []string{"svg"}, nil)
   315  	if rpt == nil {
   316  		return // error already reported
   317  	}
   318  
   319  	// Generate dot graph.
   320  	g, config := report.GetDOT(rpt)
   321  	legend := config.Labels
   322  	config.Labels = nil
   323  	dot := &bytes.Buffer{}
   324  	graph.ComposeDot(dot, g, &graph.DotAttributes{}, config)
   325  
   326  	// Convert to svg.
   327  	svg, err := dotToSvg(dot.Bytes())
   328  	if err != nil {
   329  		http.Error(w, "Could not execute dot; may need to install graphviz.",
   330  			http.StatusNotImplemented)
   331  		ui.options.UI.PrintErr("Failed to execute dot. Is Graphviz installed?\n", err)
   332  		return
   333  	}
   334  
   335  	// Get all node names into an array.
   336  	nodes := []string{""} // dot starts with node numbered 1
   337  	for _, n := range g.Nodes {
   338  		nodes = append(nodes, n.Info.Name)
   339  	}
   340  
   341  	ui.render(w, req, "graph", rpt, errList, legend, webArgs{
   342  		HTMLBody: template.HTML(string(svg)),
   343  		Nodes:    nodes,
   344  	})
   345  }
   346  
   347  func dotToSvg(dot []byte) ([]byte, error) {
   348  	cmd := exec.Command("dot", "-Tsvg")
   349  	out := &bytes.Buffer{}
   350  	cmd.Stdin, cmd.Stdout, cmd.Stderr = bytes.NewBuffer(dot), out, os.Stderr
   351  	if err := cmd.Run(); err != nil {
   352  		return nil, err
   353  	}
   354  
   355  	// Fix dot bug related to unquoted ampersands.
   356  	svg := bytes.Replace(out.Bytes(), []byte("&;"), []byte("&amp;;"), -1)
   357  
   358  	// Cleanup for embedding by dropping stuff before the <svg> start.
   359  	if pos := bytes.Index(svg, []byte("<svg")); pos >= 0 {
   360  		svg = svg[pos:]
   361  	}
   362  	return svg, nil
   363  }
   364  
   365  func (ui *webInterface) top(w http.ResponseWriter, req *http.Request) {
   366  	rpt, errList := ui.makeReport(w, req, []string{"top"}, func(cfg *config) {
   367  		cfg.NodeCount = 500
   368  	})
   369  	if rpt == nil {
   370  		return // error already reported
   371  	}
   372  	top, legend := report.TextItems(rpt)
   373  	var nodes []string
   374  	for _, item := range top {
   375  		nodes = append(nodes, item.Name)
   376  	}
   377  
   378  	ui.render(w, req, "top", rpt, errList, legend, webArgs{
   379  		Top:   top,
   380  		Nodes: nodes,
   381  	})
   382  }
   383  
   384  // disasm generates a web page containing disassembly.
   385  func (ui *webInterface) disasm(w http.ResponseWriter, req *http.Request) {
   386  	args := []string{"disasm", req.URL.Query().Get("f")}
   387  	rpt, errList := ui.makeReport(w, req, args, nil)
   388  	if rpt == nil {
   389  		return // error already reported
   390  	}
   391  
   392  	out := &bytes.Buffer{}
   393  	if err := report.PrintAssembly(out, rpt, ui.options.Obj, maxEntries); err != nil {
   394  		http.Error(w, err.Error(), http.StatusBadRequest)
   395  		ui.options.UI.PrintErr(err)
   396  		return
   397  	}
   398  
   399  	legend := report.ProfileLabels(rpt)
   400  	ui.render(w, req, "plaintext", rpt, errList, legend, webArgs{
   401  		TextBody: out.String(),
   402  	})
   403  
   404  }
   405  
   406  // source generates a web page containing source code annotated with profile
   407  // data.
   408  func (ui *webInterface) source(w http.ResponseWriter, req *http.Request) {
   409  	args := []string{"weblist", req.URL.Query().Get("f")}
   410  	rpt, errList := ui.makeReport(w, req, args, nil)
   411  	if rpt == nil {
   412  		return // error already reported
   413  	}
   414  
   415  	// Generate source listing.
   416  	listing, err := report.MakeWebList(rpt, ui.options.Obj, maxEntries)
   417  	if err != nil {
   418  		http.Error(w, err.Error(), http.StatusBadRequest)
   419  		ui.options.UI.PrintErr(err)
   420  		return
   421  	}
   422  
   423  	legend := report.ProfileLabels(rpt)
   424  	ui.render(w, req, "sourcelisting", rpt, errList, legend, webArgs{
   425  		Listing: listing,
   426  	})
   427  }
   428  
   429  // peek generates a web page listing callers/callers.
   430  func (ui *webInterface) peek(w http.ResponseWriter, req *http.Request) {
   431  	args := []string{"peek", req.URL.Query().Get("f")}
   432  	rpt, errList := ui.makeReport(w, req, args, func(cfg *config) {
   433  		cfg.Granularity = "lines"
   434  	})
   435  	if rpt == nil {
   436  		return // error already reported
   437  	}
   438  
   439  	out := &bytes.Buffer{}
   440  	if err := report.Generate(out, rpt, ui.options.Obj); err != nil {
   441  		http.Error(w, err.Error(), http.StatusBadRequest)
   442  		ui.options.UI.PrintErr(err)
   443  		return
   444  	}
   445  
   446  	legend := report.ProfileLabels(rpt)
   447  	ui.render(w, req, "plaintext", rpt, errList, legend, webArgs{
   448  		TextBody: out.String(),
   449  	})
   450  }
   451  
   452  // saveConfig saves URL configuration.
   453  func (ui *webInterface) saveConfig(w http.ResponseWriter, req *http.Request) {
   454  	if err := setConfig(ui.settingsFile, *req.URL); err != nil {
   455  		http.Error(w, err.Error(), http.StatusBadRequest)
   456  		ui.options.UI.PrintErr(err)
   457  		return
   458  	}
   459  }
   460  
   461  // deleteConfig deletes a configuration.
   462  func (ui *webInterface) deleteConfig(w http.ResponseWriter, req *http.Request) {
   463  	name := req.URL.Query().Get("config")
   464  	if err := removeConfig(ui.settingsFile, name); err != nil {
   465  		http.Error(w, err.Error(), http.StatusBadRequest)
   466  		ui.options.UI.PrintErr(err)
   467  		return
   468  	}
   469  }
   470  
   471  // getFromLegend returns the suffix of an entry in legend that starts
   472  // with param.  It returns def if no such entry is found.
   473  func getFromLegend(legend []string, param, def string) string {
   474  	for _, s := range legend {
   475  		if strings.HasPrefix(s, param) {
   476  			return s[len(param):]
   477  		}
   478  	}
   479  	return def
   480  }
   481
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