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// Copyright 2012 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.
package get
import (
"encoding/json"
"errors"
"fmt"
"internal/lazyregexp"
"internal/singleflight"
"log"
urlpkg "net/url"
"os"
"os/exec"
"path/filepath"
"regexp"
"strings"
"sync"
"cmd/go/internal/base"
"cmd/go/internal/cfg"
"cmd/go/internal/web"
)
// A vcsCmd describes how to use a version control system
// like Mercurial, Git, or Subversion.
type vcsCmd struct {
name string
cmd string // name of binary to invoke command
createCmd []string // commands to download a fresh copy of a repository
downloadCmd []string // commands to download updates into an existing repository
tagCmd []tagCmd // commands to list tags
tagLookupCmd []tagCmd // commands to lookup tags before running tagSyncCmd
tagSyncCmd []string // commands to sync to specific tag
tagSyncDefault []string // commands to sync to default tag
scheme []string
pingCmd string
remoteRepo func(v *vcsCmd, rootDir string) (remoteRepo string, err error)
resolveRepo func(v *vcsCmd, rootDir, remoteRepo string) (realRepo string, err error)
}
var defaultSecureScheme = map[string]bool{
"https": true,
"git+ssh": true,
"bzr+ssh": true,
"svn+ssh": true,
"ssh": true,
}
func (v *vcsCmd) isSecure(repo string) bool {
u, err := urlpkg.Parse(repo)
if err != nil {
// If repo is not a URL, it's not secure.
return false
}
return v.isSecureScheme(u.Scheme)
}
func (v *vcsCmd) isSecureScheme(scheme string) bool {
switch v.cmd {
case "git":
// GIT_ALLOW_PROTOCOL is an environment variable defined by Git. It is a
// colon-separated list of schemes that are allowed to be used with git
// fetch/clone. Any scheme not mentioned will be considered insecure.
if allow := os.Getenv("GIT_ALLOW_PROTOCOL"); allow != "" {
for _, s := range strings.Split(allow, ":") {
if s == scheme {
return true
}
}
return false
}
}
return defaultSecureScheme[scheme]
}
// A tagCmd describes a command to list available tags
// that can be passed to tagSyncCmd.
type tagCmd struct {
cmd string // command to list tags
pattern string // regexp to extract tags from list
}
// vcsList lists the known version control systems
var vcsList = []*vcsCmd{
vcsHg,
vcsGit,
vcsSvn,
vcsBzr,
vcsFossil,
}
// vcsByCmd returns the version control system for the given
// command name (hg, git, svn, bzr).
func vcsByCmd(cmd string) *vcsCmd {
for _, vcs := range vcsList {
if vcs.cmd == cmd {
return vcs
}
}
return nil
}
// vcsHg describes how to use Mercurial.
var vcsHg = &vcsCmd{
name: "Mercurial",
cmd: "hg",
createCmd: []string{"clone -U -- {repo} {dir}"},
downloadCmd: []string{"pull"},
// We allow both tag and branch names as 'tags'
// for selecting a version. This lets people have
// a go.release.r60 branch and a go1 branch
// and make changes in both, without constantly
// editing .hgtags.
tagCmd: []tagCmd{
{"tags", `^(\S+)`},
{"branches", `^(\S+)`},
},
tagSyncCmd: []string{"update -r {tag}"},
tagSyncDefault: []string{"update default"},
scheme: []string{"https", "http", "ssh"},
pingCmd: "identify -- {scheme}://{repo}",
remoteRepo: hgRemoteRepo,
}
func hgRemoteRepo(vcsHg *vcsCmd, rootDir string) (remoteRepo string, err error) {
out, err := vcsHg.runOutput(rootDir, "paths default")
if err != nil {
return "", err
}
return strings.TrimSpace(string(out)), nil
}
// vcsGit describes how to use Git.
var vcsGit = &vcsCmd{
name: "Git",
cmd: "git",
createCmd: []string{"clone -- {repo} {dir}", "-go-internal-cd {dir} submodule update --init --recursive"},
downloadCmd: []string{"pull --ff-only", "submodule update --init --recursive"},
tagCmd: []tagCmd{
// tags/xxx matches a git tag named xxx
// origin/xxx matches a git branch named xxx on the default remote repository
{"show-ref", `(?:tags|origin)/(\S+)$`},
},
tagLookupCmd: []tagCmd{
{"show-ref tags/{tag} origin/{tag}", `((?:tags|origin)/\S+)$`},
},
tagSyncCmd: []string{"checkout {tag}", "submodule update --init --recursive"},
// both createCmd and downloadCmd update the working dir.
// No need to do more here. We used to 'checkout master'
// but that doesn't work if the default branch is not named master.
// DO NOT add 'checkout master' here.
// See golang.org/issue/9032.
tagSyncDefault: []string{"submodule update --init --recursive"},
scheme: []string{"git", "https", "http", "git+ssh", "ssh"},
// Leave out the '--' separator in the ls-remote command: git 2.7.4 does not
// support such a separator for that command, and this use should be safe
// without it because the {scheme} value comes from the predefined list above.
// See golang.org/issue/33836.
pingCmd: "ls-remote {scheme}://{repo}",
remoteRepo: gitRemoteRepo,
}
// scpSyntaxRe matches the SCP-like addresses used by Git to access
// repositories by SSH.
var scpSyntaxRe = lazyregexp.New(`^([a-zA-Z0-9_]+)@([a-zA-Z0-9._-]+):(.*)$`)
func gitRemoteRepo(vcsGit *vcsCmd, rootDir string) (remoteRepo string, err error) {
cmd := "config remote.origin.url"
errParse := errors.New("unable to parse output of git " + cmd)
errRemoteOriginNotFound := errors.New("remote origin not found")
outb, err := vcsGit.run1(rootDir, cmd, nil, false)
if err != nil {
// if it doesn't output any message, it means the config argument is correct,
// but the config value itself doesn't exist
if outb != nil && len(outb) == 0 {
return "", errRemoteOriginNotFound
}
return "", err
}
out := strings.TrimSpace(string(outb))
var repoURL *urlpkg.URL
if m := scpSyntaxRe.FindStringSubmatch(out); m != nil {
// Match SCP-like syntax and convert it to a URL.
// Eg, "git@github.com:user/repo" becomes
// "ssh://git@github.com/user/repo".
repoURL = &urlpkg.URL{
Scheme: "ssh",
User: urlpkg.User(m[1]),
Host: m[2],
Path: m[3],
}
} else {
repoURL, err = urlpkg.Parse(out)
if err != nil {
return "", err
}
}
// Iterate over insecure schemes too, because this function simply
// reports the state of the repo. If we can't see insecure schemes then
// we can't report the actual repo URL.
for _, s := range vcsGit.scheme {
if repoURL.Scheme == s {
return repoURL.String(), nil
}
}
return "", errParse
}
// vcsBzr describes how to use Bazaar.
var vcsBzr = &vcsCmd{
name: "Bazaar",
cmd: "bzr",
createCmd: []string{"branch -- {repo} {dir}"},
// Without --overwrite bzr will not pull tags that changed.
// Replace by --overwrite-tags after http://pad.lv/681792 goes in.
downloadCmd: []string{"pull --overwrite"},
tagCmd: []tagCmd{{"tags", `^(\S+)`}},
tagSyncCmd: []string{"update -r {tag}"},
tagSyncDefault: []string{"update -r revno:-1"},
scheme: []string{"https", "http", "bzr", "bzr+ssh"},
pingCmd: "info -- {scheme}://{repo}",
remoteRepo: bzrRemoteRepo,
resolveRepo: bzrResolveRepo,
}
func bzrRemoteRepo(vcsBzr *vcsCmd, rootDir string) (remoteRepo string, err error) {
outb, err := vcsBzr.runOutput(rootDir, "config parent_location")
if err != nil {
return "", err
}
return strings.TrimSpace(string(outb)), nil
}
func bzrResolveRepo(vcsBzr *vcsCmd, rootDir, remoteRepo string) (realRepo string, err error) {
outb, err := vcsBzr.runOutput(rootDir, "info "+remoteRepo)
if err != nil {
return "", err
}
out := string(outb)
// Expect:
// ...
// (branch root|repository branch): <URL>
// ...
found := false
for _, prefix := range []string{"\n branch root: ", "\n repository branch: "} {
i := strings.Index(out, prefix)
if i >= 0 {
out = out[i+len(prefix):]
found = true
break
}
}
if !found {
return "", fmt.Errorf("unable to parse output of bzr info")
}
i := strings.Index(out, "\n")
if i < 0 {
return "", fmt.Errorf("unable to parse output of bzr info")
}
out = out[:i]
return strings.TrimSpace(out), nil
}
// vcsSvn describes how to use Subversion.
var vcsSvn = &vcsCmd{
name: "Subversion",
cmd: "svn",
createCmd: []string{"checkout -- {repo} {dir}"},
downloadCmd: []string{"update"},
// There is no tag command in subversion.
// The branch information is all in the path names.
scheme: []string{"https", "http", "svn", "svn+ssh"},
pingCmd: "info -- {scheme}://{repo}",
remoteRepo: svnRemoteRepo,
}
func svnRemoteRepo(vcsSvn *vcsCmd, rootDir string) (remoteRepo string, err error) {
outb, err := vcsSvn.runOutput(rootDir, "info")
if err != nil {
return "", err
}
out := string(outb)
// Expect:
//
// ...
// URL: <URL>
// ...
//
// Note that we're not using the Repository Root line,
// because svn allows checking out subtrees.
// The URL will be the URL of the subtree (what we used with 'svn co')
// while the Repository Root may be a much higher parent.
i := strings.Index(out, "\nURL: ")
if i < 0 {
return "", fmt.Errorf("unable to parse output of svn info")
}
out = out[i+len("\nURL: "):]
i = strings.Index(out, "\n")
if i < 0 {
return "", fmt.Errorf("unable to parse output of svn info")
}
out = out[:i]
return strings.TrimSpace(out), nil
}
// fossilRepoName is the name go get associates with a fossil repository. In the
// real world the file can be named anything.
const fossilRepoName = ".fossil"
// vcsFossil describes how to use Fossil (fossil-scm.org)
var vcsFossil = &vcsCmd{
name: "Fossil",
cmd: "fossil",
createCmd: []string{"-go-internal-mkdir {dir} clone -- {repo} " + filepath.Join("{dir}", fossilRepoName), "-go-internal-cd {dir} open .fossil"},
downloadCmd: []string{"up"},
tagCmd: []tagCmd{{"tag ls", `(.*)`}},
tagSyncCmd: []string{"up tag:{tag}"},
tagSyncDefault: []string{"up trunk"},
scheme: []string{"https", "http"},
remoteRepo: fossilRemoteRepo,
}
func fossilRemoteRepo(vcsFossil *vcsCmd, rootDir string) (remoteRepo string, err error) {
out, err := vcsFossil.runOutput(rootDir, "remote-url")
if err != nil {
return "", err
}
return strings.TrimSpace(string(out)), nil
}
func (v *vcsCmd) String() string {
return v.name
}
// run runs the command line cmd in the given directory.
// keyval is a list of key, value pairs. run expands
// instances of {key} in cmd into value, but only after
// splitting cmd into individual arguments.
// If an error occurs, run prints the command line and the
// command's combined stdout+stderr to standard error.
// Otherwise run discards the command's output.
func (v *vcsCmd) run(dir string, cmd string, keyval ...string) error {
_, err := v.run1(dir, cmd, keyval, true)
return err
}
// runVerboseOnly is like run but only generates error output to standard error in verbose mode.
func (v *vcsCmd) runVerboseOnly(dir string, cmd string, keyval ...string) error {
_, err := v.run1(dir, cmd, keyval, false)
return err
}
// runOutput is like run but returns the output of the command.
func (v *vcsCmd) runOutput(dir string, cmd string, keyval ...string) ([]byte, error) {
return v.run1(dir, cmd, keyval, true)
}
// run1 is the generalized implementation of run and runOutput.
func (v *vcsCmd) run1(dir string, cmdline string, keyval []string, verbose bool) ([]byte, error) {
m := make(map[string]string)
for i := 0; i < len(keyval); i += 2 {
m[keyval[i]] = keyval[i+1]
}
args := strings.Fields(cmdline)
for i, arg := range args {
args[i] = expand(m, arg)
}
if len(args) >= 2 && args[0] == "-go-internal-mkdir" {
var err error
if filepath.IsAbs(args[1]) {
err = os.Mkdir(args[1], os.ModePerm)
} else {
err = os.Mkdir(filepath.Join(dir, args[1]), os.ModePerm)
}
if err != nil {
return nil, err
}
args = args[2:]
}
if len(args) >= 2 && args[0] == "-go-internal-cd" {
if filepath.IsAbs(args[1]) {
dir = args[1]
} else {
dir = filepath.Join(dir, args[1])
}
args = args[2:]
}
_, err := exec.LookPath(v.cmd)
if err != nil {
fmt.Fprintf(os.Stderr,
"go: missing %s command. See https://golang.org/s/gogetcmd\n",
v.name)
return nil, err
}
cmd := exec.Command(v.cmd, args...)
cmd.Dir = dir
cmd.Env = base.EnvForDir(cmd.Dir, os.Environ())
if cfg.BuildX {
fmt.Fprintf(os.Stderr, "cd %s\n", dir)
fmt.Fprintf(os.Stderr, "%s %s\n", v.cmd, strings.Join(args, " "))
}
out, err := cmd.Output()
if err != nil {
if verbose || cfg.BuildV {
fmt.Fprintf(os.Stderr, "# cd %s; %s %s\n", dir, v.cmd, strings.Join(args, " "))
if ee, ok := err.(*exec.ExitError); ok && len(ee.Stderr) > 0 {
os.Stderr.Write(ee.Stderr)
} else {
fmt.Fprintf(os.Stderr, err.Error())
}
}
}
return out, err
}
// ping pings to determine scheme to use.
func (v *vcsCmd) ping(scheme, repo string) error {
return v.runVerboseOnly(".", v.pingCmd, "scheme", scheme, "repo", repo)
}
// create creates a new copy of repo in dir.
// The parent of dir must exist; dir must not.
func (v *vcsCmd) create(dir, repo string) error {
for _, cmd := range v.createCmd {
if err := v.run(".", cmd, "dir", dir, "repo", repo); err != nil {
return err
}
}
return nil
}
// download downloads any new changes for the repo in dir.
func (v *vcsCmd) download(dir string) error {
for _, cmd := range v.downloadCmd {
if err := v.run(dir, cmd); err != nil {
return err
}
}
return nil
}
// tags returns the list of available tags for the repo in dir.
func (v *vcsCmd) tags(dir string) ([]string, error) {
var tags []string
for _, tc := range v.tagCmd {
out, err := v.runOutput(dir, tc.cmd)
if err != nil {
return nil, err
}
re := regexp.MustCompile(`(?m-s)` + tc.pattern)
for _, m := range re.FindAllStringSubmatch(string(out), -1) {
tags = append(tags, m[1])
}
}
return tags, nil
}
// tagSync syncs the repo in dir to the named tag,
// which either is a tag returned by tags or is v.tagDefault.
func (v *vcsCmd) tagSync(dir, tag string) error {
if v.tagSyncCmd == nil {
return nil
}
if tag != "" {
for _, tc := range v.tagLookupCmd {
out, err := v.runOutput(dir, tc.cmd, "tag", tag)
if err != nil {
return err
}
re := regexp.MustCompile(`(?m-s)` + tc.pattern)
m := re.FindStringSubmatch(string(out))
if len(m) > 1 {
tag = m[1]
break
}
}
}
if tag == "" && v.tagSyncDefault != nil {
for _, cmd := range v.tagSyncDefault {
if err := v.run(dir, cmd); err != nil {
return err
}
}
return nil
}
for _, cmd := range v.tagSyncCmd {
if err := v.run(dir, cmd, "tag", tag); err != nil {
return err
}
}
return nil
}
// A vcsPath describes how to convert an import path into a
// version control system and repository name.
type vcsPath struct {
prefix string // prefix this description applies to
regexp *lazyregexp.Regexp // compiled pattern for import path
repo string // repository to use (expand with match of re)
vcs string // version control system to use (expand with match of re)
check func(match map[string]string) error // additional checks
ping bool // ping for scheme to use to download repo
}
// vcsFromDir inspects dir and its parents to determine the
// version control system and code repository to use.
// On return, root is the import path
// corresponding to the root of the repository.
func vcsFromDir(dir, srcRoot string) (vcs *vcsCmd, root string, err error) {
// Clean and double-check that dir is in (a subdirectory of) srcRoot.
dir = filepath.Clean(dir)
srcRoot = filepath.Clean(srcRoot)
if len(dir) <= len(srcRoot) || dir[len(srcRoot)] != filepath.Separator {
return nil, "", fmt.Errorf("directory %q is outside source root %q", dir, srcRoot)
}
var vcsRet *vcsCmd
var rootRet string
origDir := dir
for len(dir) > len(srcRoot) {
for _, vcs := range vcsList {
if _, err := os.Stat(filepath.Join(dir, "."+vcs.cmd)); err == nil {
root := filepath.ToSlash(dir[len(srcRoot)+1:])
// Record first VCS we find, but keep looking,
// to detect mistakes like one kind of VCS inside another.
if vcsRet == nil {
vcsRet = vcs
rootRet = root
continue
}
// Allow .git inside .git, which can arise due to submodules.
if vcsRet == vcs && vcs.cmd == "git" {
continue
}
// Otherwise, we have one VCS inside a different VCS.
return nil, "", fmt.Errorf("directory %q uses %s, but parent %q uses %s",
filepath.Join(srcRoot, rootRet), vcsRet.cmd, filepath.Join(srcRoot, root), vcs.cmd)
}
}
// Move to parent.
ndir := filepath.Dir(dir)
if len(ndir) >= len(dir) {
// Shouldn't happen, but just in case, stop.
break
}
dir = ndir
}
if vcsRet != nil {
return vcsRet, rootRet, nil
}
return nil, "", fmt.Errorf("directory %q is not using a known version control system", origDir)
}
// checkNestedVCS checks for an incorrectly-nested VCS-inside-VCS
// situation for dir, checking parents up until srcRoot.
func checkNestedVCS(vcs *vcsCmd, dir, srcRoot string) error {
if len(dir) <= len(srcRoot) || dir[len(srcRoot)] != filepath.Separator {
return fmt.Errorf("directory %q is outside source root %q", dir, srcRoot)
}
otherDir := dir
for len(otherDir) > len(srcRoot) {
for _, otherVCS := range vcsList {
if _, err := os.Stat(filepath.Join(otherDir, "."+otherVCS.cmd)); err == nil {
// Allow expected vcs in original dir.
if otherDir == dir && otherVCS == vcs {
continue
}
// Allow .git inside .git, which can arise due to submodules.
if otherVCS == vcs && vcs.cmd == "git" {
continue
}
// Otherwise, we have one VCS inside a different VCS.
return fmt.Errorf("directory %q uses %s, but parent %q uses %s", dir, vcs.cmd, otherDir, otherVCS.cmd)
}
}
// Move to parent.
newDir := filepath.Dir(otherDir)
if len(newDir) >= len(otherDir) {
// Shouldn't happen, but just in case, stop.
break
}
otherDir = newDir
}
return nil
}
// RepoRoot describes the repository root for a tree of source code.
type RepoRoot struct {
Repo string // repository URL, including scheme
Root string // import path corresponding to root of repo
IsCustom bool // defined by served <meta> tags (as opposed to hard-coded pattern)
VCS string // vcs type ("mod", "git", ...)
vcs *vcsCmd // internal: vcs command access
}
func httpPrefix(s string) string {
for _, prefix := range [...]string{"http:", "https:"} {
if strings.HasPrefix(s, prefix) {
return prefix
}
}
return ""
}
// ModuleMode specifies whether to prefer modules when looking up code sources.
type ModuleMode int
const (
IgnoreMod ModuleMode = iota
PreferMod
)
// RepoRootForImportPath analyzes importPath to determine the
// version control system, and code repository to use.
func RepoRootForImportPath(importPath string, mod ModuleMode, security web.SecurityMode) (*RepoRoot, error) {
rr, err := repoRootFromVCSPaths(importPath, "", security, vcsPaths)
if err == errUnknownSite {
rr, err = repoRootForImportDynamic(importPath, mod, security)
if err != nil {
err = fmt.Errorf("unrecognized import path %q: %v", importPath, err)
}
}
if err != nil {
rr1, err1 := repoRootFromVCSPaths(importPath, "", security, vcsPathsAfterDynamic)
if err1 == nil {
rr = rr1
err = nil
}
}
// Should have been taken care of above, but make sure.
if err == nil && strings.Contains(importPath, "...") && strings.Contains(rr.Root, "...") {
// Do not allow wildcards in the repo root.
rr = nil
err = fmt.Errorf("cannot expand ... in %q", importPath)
}
return rr, err
}
var errUnknownSite = errors.New("dynamic lookup required to find mapping")
// repoRootFromVCSPaths attempts to map importPath to a repoRoot
// using the mappings defined in vcsPaths.
// If scheme is non-empty, that scheme is forced.
func repoRootFromVCSPaths(importPath, scheme string, security web.SecurityMode, vcsPaths []*vcsPath) (*RepoRoot, error) {
// A common error is to use https://packagepath because that's what
// hg and git require. Diagnose this helpfully.
if prefix := httpPrefix(importPath); prefix != "" {
// The importPath has been cleaned, so has only one slash. The pattern
// ignores the slashes; the error message puts them back on the RHS at least.
return nil, fmt.Errorf("%q not allowed in import path", prefix+"//")
}
for _, srv := range vcsPaths {
if !strings.HasPrefix(importPath, srv.prefix) {
continue
}
m := srv.regexp.FindStringSubmatch(importPath)
if m == nil {
if srv.prefix != "" {
return nil, fmt.Errorf("invalid %s import path %q", srv.prefix, importPath)
}
continue
}
// Build map of named subexpression matches for expand.
match := map[string]string{
"prefix": srv.prefix,
"import": importPath,
}
for i, name := range srv.regexp.SubexpNames() {
if name != "" && match[name] == "" {
match[name] = m[i]
}
}
if srv.vcs != "" {
match["vcs"] = expand(match, srv.vcs)
}
if srv.repo != "" {
match["repo"] = expand(match, srv.repo)
}
if srv.check != nil {
if err := srv.check(match); err != nil {
return nil, err
}
}
vcs := vcsByCmd(match["vcs"])
if vcs == nil {
return nil, fmt.Errorf("unknown version control system %q", match["vcs"])
}
if srv.ping {
if scheme != "" {
match["repo"] = scheme + "://" + match["repo"]
} else {
for _, scheme := range vcs.scheme {
if security == web.SecureOnly && !vcs.isSecureScheme(scheme) {
continue
}
if vcs.pingCmd != "" && vcs.ping(scheme, match["repo"]) == nil {
match["repo"] = scheme + "://" + match["repo"]
goto Found
}
}
// No scheme found. Fall back to the first one.
match["repo"] = vcs.scheme[0] + "://" + match["repo"]
Found:
}
}
rr := &RepoRoot{
Repo: match["repo"],
Root: match["root"],
VCS: vcs.cmd,
vcs: vcs,
}
return rr, nil
}
return nil, errUnknownSite
}
// urlForImportPath returns a partially-populated URL for the given Go import path.
//
// The URL leaves the Scheme field blank so that web.Get will try any scheme
// allowed by the selected security mode.
func urlForImportPath(importPath string) (*urlpkg.URL, error) {
slash := strings.Index(importPath, "/")
if slash < 0 {
slash = len(importPath)
}
host, path := importPath[:slash], importPath[slash:]
if !strings.Contains(host, ".") {
return nil, errors.New("import path does not begin with hostname")
}
if len(path) == 0 {
path = "/"
}
return &urlpkg.URL{Host: host, Path: path, RawQuery: "go-get=1"}, nil
}
// repoRootForImportDynamic finds a *RepoRoot for a custom domain that's not
// statically known by repoRootForImportPathStatic.
//
// This handles custom import paths like "name.tld/pkg/foo" or just "name.tld".
func repoRootForImportDynamic(importPath string, mod ModuleMode, security web.SecurityMode) (*RepoRoot, error) {
url, err := urlForImportPath(importPath)
if err != nil {
return nil, err
}
resp, err := web.Get(security, url)
if err != nil {
msg := "https fetch: %v"
if security == web.Insecure {
msg = "http/" + msg
}
return nil, fmt.Errorf(msg, err)
}
body := resp.Body
defer body.Close()
imports, err := parseMetaGoImports(body, mod)
if len(imports) == 0 {
if respErr := resp.Err(); respErr != nil {
// If the server's status was not OK, prefer to report that instead of
// an XML parse error.
return nil, respErr
}
}
if err != nil {
return nil, fmt.Errorf("parsing %s: %v", importPath, err)
}
// Find the matched meta import.
mmi, err := matchGoImport(imports, importPath)
if err != nil {
if _, ok := err.(ImportMismatchError); !ok {
return nil, fmt.Errorf("parse %s: %v", url, err)
}
return nil, fmt.Errorf("parse %s: no go-import meta tags (%s)", resp.URL, err)
}
if cfg.BuildV {
log.Printf("get %q: found meta tag %#v at %s", importPath, mmi, url)
}
// If the import was "uni.edu/bob/project", which said the
// prefix was "uni.edu" and the RepoRoot was "evilroot.com",
// make sure we don't trust Bob and check out evilroot.com to
// "uni.edu" yet (possibly overwriting/preempting another
// non-evil student). Instead, first verify the root and see
// if it matches Bob's claim.
if mmi.Prefix != importPath {
if cfg.BuildV {
log.Printf("get %q: verifying non-authoritative meta tag", importPath)
}
var imports []metaImport
url, imports, err = metaImportsForPrefix(mmi.Prefix, mod, security)
if err != nil {
return nil, err
}
metaImport2, err := matchGoImport(imports, importPath)
if err != nil || mmi != metaImport2 {
return nil, fmt.Errorf("%s and %s disagree about go-import for %s", resp.URL, url, mmi.Prefix)
}
}
if err := validateRepoRoot(mmi.RepoRoot); err != nil {
return nil, fmt.Errorf("%s: invalid repo root %q: %v", resp.URL, mmi.RepoRoot, err)
}
vcs := vcsByCmd(mmi.VCS)
if vcs == nil && mmi.VCS != "mod" {
return nil, fmt.Errorf("%s: unknown vcs %q", resp.URL, mmi.VCS)
}
rr := &RepoRoot{
Repo: mmi.RepoRoot,
Root: mmi.Prefix,
IsCustom: true,
VCS: mmi.VCS,
vcs: vcs,
}
return rr, nil
}
// validateRepoRoot returns an error if repoRoot does not seem to be
// a valid URL with scheme.
func validateRepoRoot(repoRoot string) error {
url, err := urlpkg.Parse(repoRoot)
if err != nil {
return err
}
if url.Scheme == "" {
return errors.New("no scheme")
}
if url.Scheme == "file" {
return errors.New("file scheme disallowed")
}
return nil
}
var fetchGroup singleflight.Group
var (
fetchCacheMu sync.Mutex
fetchCache = map[string]fetchResult{} // key is metaImportsForPrefix's importPrefix
)
// metaImportsForPrefix takes a package's root import path as declared in a <meta> tag
// and returns its HTML discovery URL and the parsed metaImport lines
// found on the page.
//
// The importPath is of the form "golang.org/x/tools".
// It is an error if no imports are found.
// url will still be valid if err != nil.
// The returned url will be of the form "https://golang.org/x/tools?go-get=1"
func metaImportsForPrefix(importPrefix string, mod ModuleMode, security web.SecurityMode) (*urlpkg.URL, []metaImport, error) {
setCache := func(res fetchResult) (fetchResult, error) {
fetchCacheMu.Lock()
defer fetchCacheMu.Unlock()
fetchCache[importPrefix] = res
return res, nil
}
resi, _, _ := fetchGroup.Do(importPrefix, func() (resi interface{}, err error) {
fetchCacheMu.Lock()
if res, ok := fetchCache[importPrefix]; ok {
fetchCacheMu.Unlock()
return res, nil
}
fetchCacheMu.Unlock()
url, err := urlForImportPath(importPrefix)
if err != nil {
return setCache(fetchResult{err: err})
}
resp, err := web.Get(security, url)
if err != nil {
return setCache(fetchResult{url: url, err: fmt.Errorf("fetching %s: %v", importPrefix, err)})
}
body := resp.Body
defer body.Close()
imports, err := parseMetaGoImports(body, mod)
if len(imports) == 0 {
if respErr := resp.Err(); respErr != nil {
// If the server's status was not OK, prefer to report that instead of
// an XML parse error.
return setCache(fetchResult{url: url, err: respErr})
}
}
if err != nil {
return setCache(fetchResult{url: url, err: fmt.Errorf("parsing %s: %v", resp.URL, err)})
}
if len(imports) == 0 {
err = fmt.Errorf("fetching %s: no go-import meta tag found in %s", importPrefix, resp.URL)
}
return setCache(fetchResult{url: url, imports: imports, err: err})
})
res := resi.(fetchResult)
return res.url, res.imports, res.err
}
type fetchResult struct {
url *urlpkg.URL
imports []metaImport
err error
}
// metaImport represents the parsed <meta name="go-import"
// content="prefix vcs reporoot" /> tags from HTML files.
type metaImport struct {
Prefix, VCS, RepoRoot string
}
// pathPrefix reports whether sub is a prefix of s,
// only considering entire path components.
func pathPrefix(s, sub string) bool {
// strings.HasPrefix is necessary but not sufficient.
if !strings.HasPrefix(s, sub) {
return false
}
// The remainder after the prefix must either be empty or start with a slash.
rem := s[len(sub):]
return rem == "" || rem[0] == '/'
}
// A ImportMismatchError is returned where metaImport/s are present
// but none match our import path.
type ImportMismatchError struct {
importPath string
mismatches []string // the meta imports that were discarded for not matching our importPath
}
func (m ImportMismatchError) Error() string {
formattedStrings := make([]string, len(m.mismatches))
for i, pre := range m.mismatches {
formattedStrings[i] = fmt.Sprintf("meta tag %s did not match import path %s", pre, m.importPath)
}
return strings.Join(formattedStrings, ", ")
}
// matchGoImport returns the metaImport from imports matching importPath.
// An error is returned if there are multiple matches.
// An ImportMismatchError is returned if none match.
func matchGoImport(imports []metaImport, importPath string) (metaImport, error) {
match := -1
errImportMismatch := ImportMismatchError{importPath: importPath}
for i, im := range imports {
if !pathPrefix(importPath, im.Prefix) {
errImportMismatch.mismatches = append(errImportMismatch.mismatches, im.Prefix)
continue
}
if match >= 0 {
if imports[match].VCS == "mod" && im.VCS != "mod" {
// All the mod entries precede all the non-mod entries.
// We have a mod entry and don't care about the rest,
// matching or not.
break
}
return metaImport{}, fmt.Errorf("multiple meta tags match import path %q", importPath)
}
match = i
}
if match == -1 {
return metaImport{}, errImportMismatch
}
return imports[match], nil
}
// expand rewrites s to replace {k} with match[k] for each key k in match.
func expand(match map[string]string, s string) string {
// We want to replace each match exactly once, and the result of expansion
// must not depend on the iteration order through the map.
// A strings.Replacer has exactly the properties we're looking for.
oldNew := make([]string, 0, 2*len(match))
for k, v := range match {
oldNew = append(oldNew, "{"+k+"}", v)
}
return strings.NewReplacer(oldNew...).Replace(s)
}
// vcsPaths defines the meaning of import paths referring to
// commonly-used VCS hosting sites (github.com/user/dir)
// and import paths referring to a fully-qualified importPath
// containing a VCS type (foo.com/repo.git/dir)
var vcsPaths = []*vcsPath{
// Github
{
prefix: "github.com/",
regexp: lazyregexp.New(`^(?P<root>github\.com/[A-Za-z0-9_.\-]+/[A-Za-z0-9_.\-]+)(/[\p{L}0-9_.\-]+)*$`),
vcs: "git",
repo: "https://{root}",
check: noVCSSuffix,
},
// Bitbucket
{
prefix: "bitbucket.org/",
regexp: lazyregexp.New(`^(?P<root>bitbucket\.org/(?P<bitname>[A-Za-z0-9_.\-]+/[A-Za-z0-9_.\-]+))(/[A-Za-z0-9_.\-]+)*$`),
repo: "https://{root}",
check: bitbucketVCS,
},
// IBM DevOps Services (JazzHub)
{
prefix: "hub.jazz.net/git/",
regexp: lazyregexp.New(`^(?P<root>hub\.jazz\.net/git/[a-z0-9]+/[A-Za-z0-9_.\-]+)(/[A-Za-z0-9_.\-]+)*$`),
vcs: "git",
repo: "https://{root}",
check: noVCSSuffix,
},
// Git at Apache
{
prefix: "git.apache.org/",
regexp: lazyregexp.New(`^(?P<root>git\.apache\.org/[a-z0-9_.\-]+\.git)(/[A-Za-z0-9_.\-]+)*$`),
vcs: "git",
repo: "https://{root}",
},
// Git at OpenStack
{
prefix: "git.openstack.org/",
regexp: lazyregexp.New(`^(?P<root>git\.openstack\.org/[A-Za-z0-9_.\-]+/[A-Za-z0-9_.\-]+)(\.git)?(/[A-Za-z0-9_.\-]+)*$`),
vcs: "git",
repo: "https://{root}",
},
// chiselapp.com for fossil
{
prefix: "chiselapp.com/",
regexp: lazyregexp.New(`^(?P<root>chiselapp\.com/user/[A-Za-z0-9]+/repository/[A-Za-z0-9_.\-]+)$`),
vcs: "fossil",
repo: "https://{root}",
},
// General syntax for any server.
// Must be last.
{
regexp: lazyregexp.New(`(?P<root>(?P<repo>([a-z0-9.\-]+\.)+[a-z0-9.\-]+(:[0-9]+)?(/~?[A-Za-z0-9_.\-]+)+?)\.(?P<vcs>bzr|fossil|git|hg|svn))(/~?[A-Za-z0-9_.\-]+)*$`),
ping: true,
},
}
// vcsPathsAfterDynamic gives additional vcsPaths entries
// to try after the dynamic HTML check.
// This gives those sites a chance to introduce <meta> tags
// as part of a graceful transition away from the hard-coded logic.
var vcsPathsAfterDynamic = []*vcsPath{
// Launchpad. See golang.org/issue/11436.
{
prefix: "launchpad.net/",
regexp: lazyregexp.New(`^(?P<root>launchpad\.net/((?P<project>[A-Za-z0-9_.\-]+)(?P<series>/[A-Za-z0-9_.\-]+)?|~[A-Za-z0-9_.\-]+/(\+junk|[A-Za-z0-9_.\-]+)/[A-Za-z0-9_.\-]+))(/[A-Za-z0-9_.\-]+)*$`),
vcs: "bzr",
repo: "https://{root}",
check: launchpadVCS,
},
}
// noVCSSuffix checks that the repository name does not
// end in .foo for any version control system foo.
// The usual culprit is ".git".
func noVCSSuffix(match map[string]string) error {
repo := match["repo"]
for _, vcs := range vcsList {
if strings.HasSuffix(repo, "."+vcs.cmd) {
return fmt.Errorf("invalid version control suffix in %s path", match["prefix"])
}
}
return nil
}
// bitbucketVCS determines the version control system for a
// Bitbucket repository, by using the Bitbucket API.
func bitbucketVCS(match map[string]string) error {
if err := noVCSSuffix(match); err != nil {
return err
}
var resp struct {
SCM string `json:"scm"`
}
url := &urlpkg.URL{
Scheme: "https",
Host: "api.bitbucket.org",
Path: expand(match, "/2.0/repositories/{bitname}"),
RawQuery: "fields=scm",
}
data, err := web.GetBytes(url)
if err != nil {
if httpErr, ok := err.(*web.HTTPError); ok && httpErr.StatusCode == 403 {
// this may be a private repository. If so, attempt to determine which
// VCS it uses. See issue 5375.
root := match["root"]
for _, vcs := range []string{"git", "hg"} {
if vcsByCmd(vcs).ping("https", root) == nil {
resp.SCM = vcs
break
}
}
}
if resp.SCM == "" {
return err
}
} else {
if err := json.Unmarshal(data, &resp); err != nil {
return fmt.Errorf("decoding %s: %v", url, err)
}
}
if vcsByCmd(resp.SCM) != nil {
match["vcs"] = resp.SCM
if resp.SCM == "git" {
match["repo"] += ".git"
}
return nil
}
return fmt.Errorf("unable to detect version control system for bitbucket.org/ path")
}
// launchpadVCS solves the ambiguity for "lp.net/project/foo". In this case,
// "foo" could be a series name registered in Launchpad with its own branch,
// and it could also be the name of a directory within the main project
// branch one level up.
func launchpadVCS(match map[string]string) error {
if match["project"] == "" || match["series"] == "" {
return nil
}
url := &urlpkg.URL{
Scheme: "https",
Host: "code.launchpad.net",
Path: expand(match, "/{project}{series}/.bzr/branch-format"),
}
_, err := web.GetBytes(url)
if err != nil {
match["root"] = expand(match, "launchpad.net/{project}")
match["repo"] = expand(match, "https://{root}")
}
return nil
}
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