package module import ( "bytes" "fmt" "io/ioutil" "net/url" "os" "os/exec" "path/filepath" "regexp" "strings" "syscall" ) // Getter defines the interface that schemes must implement to download // and update modules. type Getter interface { // Get downloads the given URL into the given directory. This always // assumes that we're updating and gets the latest version that it can. // // The directory may already exist (if we're updating). If it is in a // format that isn't understood, an error should be returned. Get shouldn't // simply nuke the directory. Get(string, *url.URL) error } // Getters is the mapping of scheme to the Getter implementation that will // be used to get a dependency. var Getters map[string]Getter // forcedRegexp is the regular expression that finds forced getters. This // syntax is schema::url, example: git::https://foo.com var forcedRegexp = regexp.MustCompile(`^([A-Za-z]+)::(.+)$`) func init() { httpGetter := new(HttpGetter) Getters = map[string]Getter{ "file": new(FileGetter), "git": new(GitGetter), "hg": new(HgGetter), "http": httpGetter, "https": httpGetter, } } // Get downloads the module specified by src into the folder specified by // dst. If dst already exists, Get will attempt to update it. // // src is a URL, whereas dst is always just a file path to a folder. This // folder doesn't need to exist. It will be created if it doesn't exist. func Get(dst, src string) error { var force string force, src = getForcedGetter(src) // If there is a subdir component, then we download the root separately // and then copy over the proper subdir. var realDst string src, subDir := getDirSubdir(src) if subDir != "" { tmpDir, err := ioutil.TempDir("", "tf") if err != nil { return err } if err := os.RemoveAll(tmpDir); err != nil { return err } defer os.RemoveAll(tmpDir) realDst = dst dst = subDir } u, err := url.Parse(src) if err != nil { return err } if force == "" { force = u.Scheme } g, ok := Getters[force] if !ok { return fmt.Errorf( "module download not supported for scheme '%s'", force) } err = g.Get(dst, u) if err != nil { err = fmt.Errorf("error downloading module '%s': %s", src, err) return err } // If we have a subdir, copy that over if subDir != "" { if err := os.RemoveAll(realDst); err != nil { return err } if err := os.MkdirAll(realDst, 0755); err != nil { return err } return copyDir(realDst, filepath.Join(dst, subDir)) } return nil } // GetCopy is the same as Get except that it downloads a copy of the // module represented by source. // // This copy will omit and dot-prefixed files (such as .git/, .hg/) and // can't be updated on its own. func GetCopy(dst, src string) error { // Create the temporary directory to do the real Get to tmpDir, err := ioutil.TempDir("", "tf") if err != nil { return err } if err := os.RemoveAll(tmpDir); err != nil { return err } defer os.RemoveAll(tmpDir) // Get to that temporary dir if err := Get(tmpDir, src); err != nil { return err } // Make sure the destination exists if err := os.MkdirAll(dst, 0755); err != nil { return err } // Copy to the final location return copyDir(dst, tmpDir) } // getRunCommand is a helper that will run a command and capture the output // in the case an error happens. func getRunCommand(cmd *exec.Cmd) error { var buf bytes.Buffer cmd.Stdout = &buf cmd.Stderr = &buf err := cmd.Run() if err == nil { return nil } if exiterr, ok := err.(*exec.ExitError); ok { // The program has exited with an exit code != 0 if status, ok := exiterr.Sys().(syscall.WaitStatus); ok { return fmt.Errorf( "%s exited with %d: %s", cmd.Path, status.ExitStatus(), buf.String()) } } return fmt.Errorf("error running %s: %s", cmd.Path, buf.String()) } // getDirSubdir takes a source and returns a tuple of the URL without // the subdir and the URL with the subdir. func getDirSubdir(src string) (string, string) { // Calcaulate an offset to avoid accidentally marking the scheme // as the dir. var offset int if idx := strings.Index(src, "://"); idx > -1 { offset = idx + 3 } // First see if we even have an explicit subdir idx := strings.Index(src[offset:], "//") if idx == -1 { return src, "" } idx += offset subdir := src[idx+2:] src = src[:idx] // Next, check if we have query parameters and push them onto the // URL. if idx = strings.Index(subdir, "?"); idx > -1 { query := subdir[idx:] subdir = subdir[:idx] src += query } return src, subdir } // getForcedGetter takes a source and returns the tuple of the forced // getter and the raw URL (without the force syntax). func getForcedGetter(src string) (string, string) { var forced string if ms := forcedRegexp.FindStringSubmatch(src); ms != nil { forced = ms[1] src = ms[2] } return forced, src }