| // Copyright 2009 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| // godoc: Go Documentation Server |
| |
| // Web server tree: |
| // |
| // http://godoc/ redirect to /pkg/ |
| // http://godoc/src/ serve files from $GOROOT/src; .go gets pretty-printed |
| // http://godoc/cmd/ serve documentation about commands |
| // http://godoc/pkg/ serve documentation about packages |
| // (idea is if you say import "compress/zlib", you go to |
| // http://godoc/pkg/compress/zlib) |
| // |
| |
| package main |
| |
| import ( |
| "archive/zip" |
| "bytes" |
| "context" |
| "encoding/json" |
| _ "expvar" // to serve /debug/vars |
| "flag" |
| "fmt" |
| "go/build" |
| "io" |
| "log" |
| "net/http" |
| _ "net/http/pprof" // to serve /debug/pprof/* |
| "net/url" |
| "os" |
| "path" |
| "path/filepath" |
| "regexp" |
| "runtime" |
| "strings" |
| |
| exec "golang.org/x/sys/execabs" |
| |
| "golang.org/x/tools/godoc" |
| "golang.org/x/tools/godoc/static" |
| "golang.org/x/tools/godoc/vfs" |
| "golang.org/x/tools/godoc/vfs/gatefs" |
| "golang.org/x/tools/godoc/vfs/mapfs" |
| "golang.org/x/tools/godoc/vfs/zipfs" |
| "golang.org/x/tools/internal/gocommand" |
| "golang.org/x/xerrors" |
| ) |
| |
| const defaultAddr = "localhost:6060" // default webserver address |
| |
| var ( |
| // file system to serve |
| // (with e.g.: zip -r go.zip $GOROOT -i \*.go -i \*.html -i \*.css -i \*.js -i \*.txt -i \*.c -i \*.h -i \*.s -i \*.png -i \*.jpg -i \*.sh -i favicon.ico) |
| zipfile = flag.String("zip", "", "zip file providing the file system to serve; disabled if empty") |
| |
| // file-based index |
| writeIndex = flag.Bool("write_index", false, "write index to a file; the file name must be specified with -index_files") |
| |
| // network |
| httpAddr = flag.String("http", defaultAddr, "HTTP service address") |
| |
| // layout control |
| urlFlag = flag.String("url", "", "print HTML for named URL") |
| |
| verbose = flag.Bool("v", false, "verbose mode") |
| |
| // file system roots |
| // TODO(gri) consider the invariant that goroot always end in '/' |
| goroot = flag.String("goroot", findGOROOT(), "Go root directory") |
| |
| // layout control |
| showTimestamps = flag.Bool("timestamps", false, "show timestamps with directory listings") |
| templateDir = flag.String("templates", "", "load templates/JS/CSS from disk in this directory") |
| showPlayground = flag.Bool("play", false, "enable playground") |
| declLinks = flag.Bool("links", true, "link identifiers to their declarations") |
| |
| // search index |
| indexEnabled = flag.Bool("index", false, "enable search index") |
| indexFiles = flag.String("index_files", "", "glob pattern specifying index files; if not empty, the index is read from these files in sorted order") |
| indexInterval = flag.Duration("index_interval", 0, "interval of indexing; 0 for default (5m), negative to only index once at startup") |
| maxResults = flag.Int("maxresults", 10000, "maximum number of full text search results shown") |
| indexThrottle = flag.Float64("index_throttle", 0.75, "index throttle value; 0.0 = no time allocated, 1.0 = full throttle") |
| |
| // source code notes |
| notesRx = flag.String("notes", "BUG", "regular expression matching note markers to show") |
| ) |
| |
| // An httpResponseRecorder is an http.ResponseWriter |
| type httpResponseRecorder struct { |
| body *bytes.Buffer |
| header http.Header |
| code int |
| } |
| |
| func (w *httpResponseRecorder) Header() http.Header { return w.header } |
| func (w *httpResponseRecorder) Write(b []byte) (int, error) { return w.body.Write(b) } |
| func (w *httpResponseRecorder) WriteHeader(code int) { w.code = code } |
| |
| func usage() { |
| fmt.Fprintf(os.Stderr, "usage: godoc -http="+defaultAddr+"\n") |
| flag.PrintDefaults() |
| os.Exit(2) |
| } |
| |
| func loggingHandler(h http.Handler) http.Handler { |
| return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) { |
| log.Printf("%s\t%s", req.RemoteAddr, req.URL) |
| h.ServeHTTP(w, req) |
| }) |
| } |
| |
| func handleURLFlag() { |
| // Try up to 10 fetches, following redirects. |
| urlstr := *urlFlag |
| for i := 0; i < 10; i++ { |
| // Prepare request. |
| u, err := url.Parse(urlstr) |
| if err != nil { |
| log.Fatal(err) |
| } |
| req := &http.Request{ |
| URL: u, |
| } |
| |
| // Invoke default HTTP handler to serve request |
| // to our buffering httpWriter. |
| w := &httpResponseRecorder{code: 200, header: make(http.Header), body: new(bytes.Buffer)} |
| http.DefaultServeMux.ServeHTTP(w, req) |
| |
| // Return data, error, or follow redirect. |
| switch w.code { |
| case 200: // ok |
| os.Stdout.Write(w.body.Bytes()) |
| return |
| case 301, 302, 303, 307: // redirect |
| redirect := w.header.Get("Location") |
| if redirect == "" { |
| log.Fatalf("HTTP %d without Location header", w.code) |
| } |
| urlstr = redirect |
| default: |
| log.Fatalf("HTTP error %d", w.code) |
| } |
| } |
| log.Fatalf("too many redirects") |
| } |
| |
| func initCorpus(corpus *godoc.Corpus) { |
| err := corpus.Init() |
| if err != nil { |
| log.Fatal(err) |
| } |
| } |
| |
| func main() { |
| flag.Usage = usage |
| flag.Parse() |
| |
| // Check usage. |
| if flag.NArg() > 0 { |
| fmt.Fprintln(os.Stderr, `Unexpected arguments. Use "go doc" for command-line help output instead. For example, "go doc fmt.Printf".`) |
| usage() |
| } |
| if *httpAddr == "" && *urlFlag == "" && !*writeIndex { |
| fmt.Fprintln(os.Stderr, "At least one of -http, -url, or -write_index must be set to a non-zero value.") |
| usage() |
| } |
| |
| // Set the resolved goroot. |
| vfs.GOROOT = *goroot |
| |
| fsGate := make(chan bool, 20) |
| |
| // Determine file system to use. |
| if *zipfile == "" { |
| // use file system of underlying OS |
| rootfs := gatefs.New(vfs.OS(*goroot), fsGate) |
| fs.Bind("/", rootfs, "/", vfs.BindReplace) |
| } else { |
| // use file system specified via .zip file (path separator must be '/') |
| rc, err := zip.OpenReader(*zipfile) |
| if err != nil { |
| log.Fatalf("%s: %s\n", *zipfile, err) |
| } |
| defer rc.Close() // be nice (e.g., -writeIndex mode) |
| fs.Bind("/", zipfs.New(rc, *zipfile), *goroot, vfs.BindReplace) |
| } |
| if *templateDir != "" { |
| fs.Bind("/lib/godoc", vfs.OS(*templateDir), "/", vfs.BindBefore) |
| fs.Bind("/favicon.ico", vfs.OS(*templateDir), "/favicon.ico", vfs.BindReplace) |
| } else { |
| fs.Bind("/lib/godoc", mapfs.New(static.Files), "/", vfs.BindReplace) |
| fs.Bind("/favicon.ico", mapfs.New(static.Files), "/favicon.ico", vfs.BindReplace) |
| } |
| |
| // Get the GOMOD value, use it to determine if godoc is being invoked in module mode. |
| goModFile, err := goMod() |
| if err != nil { |
| fmt.Fprintf(os.Stderr, "failed to determine go env GOMOD value: %v", err) |
| goModFile = "" // Fall back to GOPATH mode. |
| } |
| |
| if goModFile != "" { |
| fmt.Printf("using module mode; GOMOD=%s\n", goModFile) |
| |
| // Detect whether to use vendor mode or not. |
| mainMod, vendorEnabled, err := gocommand.VendorEnabled(context.Background(), gocommand.Invocation{}, &gocommand.Runner{}) |
| if err != nil { |
| fmt.Fprintf(os.Stderr, "failed to determine if vendoring is enabled: %v", err) |
| os.Exit(1) |
| } |
| if vendorEnabled { |
| // Bind the root directory of the main module. |
| fs.Bind(path.Join("/src", mainMod.Path), gatefs.New(vfs.OS(mainMod.Dir), fsGate), "/", vfs.BindAfter) |
| |
| // Bind the vendor directory. |
| // |
| // Note that in module mode, vendor directories in locations |
| // other than the main module's root directory are ignored. |
| // See https://golang.org/ref/mod#vendoring. |
| vendorDir := filepath.Join(mainMod.Dir, "vendor") |
| fs.Bind("/src", gatefs.New(vfs.OS(vendorDir), fsGate), "/", vfs.BindAfter) |
| |
| } else { |
| // Try to download dependencies that are not in the module cache in order to |
| // to show their documentation. |
| // This may fail if module downloading is disallowed (GOPROXY=off) or due to |
| // limited connectivity, in which case we print errors to stderr and show |
| // documentation only for packages that are available. |
| fillModuleCache(os.Stderr, goModFile) |
| |
| // Determine modules in the build list. |
| mods, err := buildList(goModFile) |
| if err != nil { |
| fmt.Fprintf(os.Stderr, "failed to determine the build list of the main module: %v", err) |
| os.Exit(1) |
| } |
| |
| // Bind module trees into Go root. |
| for _, m := range mods { |
| if m.Dir == "" { |
| // Module is not available in the module cache, skip it. |
| continue |
| } |
| dst := path.Join("/src", m.Path) |
| fs.Bind(dst, gatefs.New(vfs.OS(m.Dir), fsGate), "/", vfs.BindAfter) |
| } |
| } |
| } else { |
| fmt.Println("using GOPATH mode") |
| |
| // Bind $GOPATH trees into Go root. |
| for _, p := range filepath.SplitList(build.Default.GOPATH) { |
| fs.Bind("/src", gatefs.New(vfs.OS(p), fsGate), "/src", vfs.BindAfter) |
| } |
| } |
| |
| var corpus *godoc.Corpus |
| if goModFile != "" { |
| corpus = godoc.NewCorpus(moduleFS{fs}) |
| } else { |
| corpus = godoc.NewCorpus(fs) |
| } |
| corpus.Verbose = *verbose |
| corpus.MaxResults = *maxResults |
| corpus.IndexEnabled = *indexEnabled |
| if *maxResults == 0 { |
| corpus.IndexFullText = false |
| } |
| corpus.IndexFiles = *indexFiles |
| corpus.IndexDirectory = func(dir string) bool { |
| return dir != "/pkg" && !strings.HasPrefix(dir, "/pkg/") |
| } |
| corpus.IndexThrottle = *indexThrottle |
| corpus.IndexInterval = *indexInterval |
| if *writeIndex || *urlFlag != "" { |
| corpus.IndexThrottle = 1.0 |
| corpus.IndexEnabled = true |
| initCorpus(corpus) |
| } else { |
| go initCorpus(corpus) |
| } |
| |
| // Initialize the version info before readTemplates, which saves |
| // the map value in a method value. |
| corpus.InitVersionInfo() |
| |
| pres = godoc.NewPresentation(corpus) |
| pres.ShowTimestamps = *showTimestamps |
| pres.ShowPlayground = *showPlayground |
| pres.DeclLinks = *declLinks |
| if *notesRx != "" { |
| pres.NotesRx = regexp.MustCompile(*notesRx) |
| } |
| |
| readTemplates(pres) |
| registerHandlers(pres) |
| |
| if *writeIndex { |
| // Write search index and exit. |
| if *indexFiles == "" { |
| log.Fatal("no index file specified") |
| } |
| |
| log.Println("initialize file systems") |
| *verbose = true // want to see what happens |
| |
| corpus.UpdateIndex() |
| |
| log.Println("writing index file", *indexFiles) |
| f, err := os.Create(*indexFiles) |
| if err != nil { |
| log.Fatal(err) |
| } |
| index, _ := corpus.CurrentIndex() |
| _, err = index.WriteTo(f) |
| if err != nil { |
| log.Fatal(err) |
| } |
| |
| log.Println("done") |
| return |
| } |
| |
| // Print content that would be served at the URL *urlFlag. |
| if *urlFlag != "" { |
| handleURLFlag() |
| return |
| } |
| |
| var handler http.Handler = http.DefaultServeMux |
| if *verbose { |
| log.Printf("Go Documentation Server") |
| log.Printf("version = %s", runtime.Version()) |
| log.Printf("address = %s", *httpAddr) |
| log.Printf("goroot = %s", *goroot) |
| switch { |
| case !*indexEnabled: |
| log.Print("search index disabled") |
| case *maxResults > 0: |
| log.Printf("full text index enabled (maxresults = %d)", *maxResults) |
| default: |
| log.Print("identifier search index enabled") |
| } |
| fs.Fprint(os.Stderr) |
| handler = loggingHandler(handler) |
| } |
| |
| // Initialize search index. |
| if *indexEnabled { |
| go corpus.RunIndexer() |
| } |
| |
| // Start http server. |
| if *verbose { |
| log.Println("starting HTTP server") |
| } |
| if err := http.ListenAndServe(*httpAddr, handler); err != nil { |
| log.Fatalf("ListenAndServe %s: %v", *httpAddr, err) |
| } |
| } |
| |
| // goMod returns the go env GOMOD value in the current directory |
| // by invoking the go command. |
| // |
| // GOMOD is documented at https://golang.org/cmd/go/#hdr-Environment_variables: |
| // |
| // The absolute path to the go.mod of the main module, |
| // or the empty string if not using modules. |
| // |
| func goMod() (string, error) { |
| out, err := exec.Command("go", "env", "-json", "GOMOD").Output() |
| if ee := (*exec.ExitError)(nil); xerrors.As(err, &ee) { |
| return "", fmt.Errorf("go command exited unsuccessfully: %v\n%s", ee.ProcessState.String(), ee.Stderr) |
| } else if err != nil { |
| return "", err |
| } |
| var env struct { |
| GoMod string |
| } |
| err = json.Unmarshal(out, &env) |
| if err != nil { |
| return "", err |
| } |
| return env.GoMod, nil |
| } |
| |
| // fillModuleCache does a best-effort attempt to fill the module cache |
| // with all dependencies of the main module in the current directory |
| // by invoking the go command. Module download logs are streamed to w. |
| // If there are any problems encountered, they are also written to w. |
| // It should only be used in module mode, when vendor mode isn't on. |
| // |
| // See https://golang.org/cmd/go/#hdr-Download_modules_to_local_cache. |
| func fillModuleCache(w io.Writer, goMod string) { |
| if goMod == os.DevNull { |
| // No module requirements, nothing to do. |
| return |
| } |
| |
| cmd := exec.Command("go", "mod", "download", "-json") |
| var out bytes.Buffer |
| cmd.Stdout = &out |
| cmd.Stderr = w |
| err := cmd.Run() |
| if ee := (*exec.ExitError)(nil); xerrors.As(err, &ee) && ee.ExitCode() == 1 { |
| // Exit code 1 from this command means there were some |
| // non-empty Error values in the output. Print them to w. |
| fmt.Fprintf(w, "documentation for some packages is not shown:\n") |
| for dec := json.NewDecoder(&out); ; { |
| var m struct { |
| Path string // Module path. |
| Version string // Module version. |
| Error string // Error loading module. |
| } |
| err := dec.Decode(&m) |
| if err == io.EOF { |
| break |
| } else if err != nil { |
| fmt.Fprintf(w, "error decoding JSON object from go mod download -json: %v\n", err) |
| continue |
| } |
| if m.Error == "" { |
| continue |
| } |
| fmt.Fprintf(w, "\tmodule %s@%s is not in the module cache and there was a problem downloading it: %s\n", m.Path, m.Version, m.Error) |
| } |
| } else if err != nil { |
| fmt.Fprintf(w, "there was a problem filling module cache: %v\n", err) |
| } |
| } |
| |
| type mod struct { |
| Path string // Module path. |
| Dir string // Directory holding files for this module, if any. |
| } |
| |
| // buildList determines the build list in the current directory |
| // by invoking the go command. It should only be used in module mode, |
| // when vendor mode isn't on. |
| // |
| // See https://golang.org/cmd/go/#hdr-The_main_module_and_the_build_list. |
| func buildList(goMod string) ([]mod, error) { |
| if goMod == os.DevNull { |
| // Empty build list. |
| return nil, nil |
| } |
| |
| out, err := exec.Command("go", "list", "-m", "-json", "all").Output() |
| if ee := (*exec.ExitError)(nil); xerrors.As(err, &ee) { |
| return nil, fmt.Errorf("go command exited unsuccessfully: %v\n%s", ee.ProcessState.String(), ee.Stderr) |
| } else if err != nil { |
| return nil, err |
| } |
| var mods []mod |
| for dec := json.NewDecoder(bytes.NewReader(out)); ; { |
| var m mod |
| err := dec.Decode(&m) |
| if err == io.EOF { |
| break |
| } else if err != nil { |
| return nil, err |
| } |
| mods = append(mods, m) |
| } |
| return mods, nil |
| } |
| |
| // moduleFS is a vfs.FileSystem wrapper used when godoc is running |
| // in module mode. It's needed so that packages inside modules are |
| // considered to be third party. |
| // |
| // It overrides the RootType method of the underlying filesystem |
| // and implements it using a heuristic based on the import path. |
| // If the first element of the import path does not contain a dot, |
| // that package is considered to be inside GOROOT. If it contains |
| // a dot, then that package is considered to be third party. |
| // |
| // TODO(dmitshur): The RootType abstraction works well when GOPATH |
| // workspaces are bound at their roots, but scales poorly in the |
| // general case. It should be replaced by a more direct solution |
| // for determining whether a package is third party or not. |
| // |
| type moduleFS struct{ vfs.FileSystem } |
| |
| func (moduleFS) RootType(path string) vfs.RootType { |
| if !strings.HasPrefix(path, "/src/") { |
| return "" |
| } |
| domain := path[len("/src/"):] |
| if i := strings.Index(domain, "/"); i >= 0 { |
| domain = domain[:i] |
| } |
| if !strings.Contains(domain, ".") { |
| // No dot in the first element of import path |
| // suggests this is a package in GOROOT. |
| return vfs.RootTypeGoRoot |
| } else { |
| // A dot in the first element of import path |
| // suggests this is a third party package. |
| return vfs.RootTypeGoPath |
| } |
| } |
| func (fs moduleFS) String() string { return "module(" + fs.FileSystem.String() + ")" } |