init

config/util.go

@@ -0,0 +1,191 @@
+package config
+
+import (
+	"github.com/ulikunitz/xz"
+
+	"archive/tar"
+	"archive/zip"
+	"compress/gzip"
+	"errors"
+	"io"
+	"io/fs"
+	"mime"
+	"net/http"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strconv"
+	"strings"
+)
+
+var (
+	ErrUnsupportedOSAndArch = errors.New("no download available for your operating system and hardware architecture")
+	ErrFileNotFoundInArchive = errors.New("file not found in archive")
+	ErrUnsupportedArchive = errors.New("unsupported archive format (supported are .tar, .tar.gz, .tar.xz and .zip")
+)
+
+func download(executable bool, urlsByOS map[string]map[string]string, progCallback func(progress float32)) (filename string, err error) {
+	// Find appropriate URL
+	var url string
+	var urlByArch map[string]string
+	var ok bool
+	if urlByArch, ok = urlsByOS[runtime.GOOS]; !ok {
+		urlByArch, ok = urlsByOS["any"]
+	}
+	if ok {
+		if url, ok = urlByArch[runtime.GOARCH]; !ok {
+			url, ok = urlByArch["any"]
+		}
+	}
+	if !ok {
+		return "", ErrUnsupportedOSAndArch
+	}
+
+	// Initiate request
+	lastPath := url
+	resp, err := http.Get(url)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+
+	// Get the filename to save the downloaded file to
+	var savePath string
+	if v := resp.Header.Get("Content-Disposition"); v != "" {
+		disposition, params, err := mime.ParseMediaType(v)
+		if err != nil {
+			return "", err
+		}
+		if disposition == "attachment" {
+			lastPath = params["filename"]
+		}
+	}
+	if savePath == "" {
+		sp := strings.Split(lastPath, "/")
+		savePath = sp[len(sp)-1]
+	}
+
+	// Download resource
+	size, _ := strconv.Atoi(resp.Header.Get("content-length"))
+	var perms uint32 = 0666
+	if executable {
+		perms = 0777
+	}
+	file, err := os.OpenFile(savePath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, fs.FileMode(perms))
+	if err != nil {
+		return "", err
+	}
+	for i := 0; ; i += 100_000 {
+		_, err := io.CopyN(file, resp.Body, 100_000)
+		if err != nil {
+			if err == io.EOF {
+				break
+			} else {
+				return "", err
+			}
+		}
+		if progCallback != nil && size != 0 {
+			progCallback(float32(i)/float32(size))
+		}
+	}
+	return savePath, nil
+}
+
+func unarchiveSingleFile(archive, target string) error {
+	unzip := func() error {
+		ar, err := zip.OpenReader(archive)
+		if err != nil {
+			return err
+		}
+		defer ar.Close()
+
+		found := false
+		for _, file := range ar.File {
+			if !file.FileInfo().IsDir() && filepath.Base(file.Name) == target {
+				found = true
+				dstFile, err := os.OpenFile(target, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, file.Mode())
+				if err != nil {
+					return err
+				}
+				defer dstFile.Close()
+				fileReader, err := file.Open()
+				if err != nil {
+					return err
+				}
+				defer fileReader.Close()
+				if _, err := io.Copy(dstFile, fileReader); err != nil {
+					return err
+				}
+			}
+		}
+		if !found {
+			return ErrFileNotFoundInArchive
+		}
+		return nil
+	}
+	untar := func(rd io.Reader) error {
+		ar := tar.NewReader(rd)
+		for {
+			hdr, err := ar.Next()
+			if err == io.EOF {
+				break
+			}
+			if err != nil {
+				return err
+			}
+			if hdr.Typeflag == tar.TypeReg && filepath.Base(hdr.Name) == target {
+				dstFile, err := os.OpenFile(target, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, fs.FileMode(hdr.Mode))
+				if err != nil {
+					return err
+				}
+				defer dstFile.Close()
+				if _, err := io.Copy(dstFile, ar); err != nil {
+					return err
+				}
+				return nil
+			}
+		}
+		return ErrFileNotFoundInArchive
+	}
+	match := func(name string, patterns ...string) bool {
+		for _, pattern := range patterns {
+			matches, err := filepath.Match(pattern, archive)
+			if err != nil {
+				panic(err)
+			}
+			if matches {
+				return true
+			}
+		}
+		return false
+	}
+	if match(archive, "*.zip") {
+		return unzip()
+	} else if match(archive, "*.tar", "*.tar.[gx]z") {
+		file, err := os.Open(archive)
+		if err != nil {
+			return err
+		}
+		defer file.Close()
+		var uncompressedFile io.Reader
+		if match(archive, "*.tar") {
+			uncompressedFile = file
+		} else if match(archive, "*.tar.gz") {
+			gz, err := gzip.NewReader(file)
+			if err != nil {
+				return err
+			}
+			defer gz.Close()
+			uncompressedFile = gz
+		} else if match(archive, "*.tar.xz") {
+			uncompressedFile, err = xz.NewReader(file)
+			if err != nil {
+				return err
+			}
+		}
+		return untar(uncompressedFile)
+	} else {
+		return ErrUnsupportedArchive
+	}
+	return nil
+}