feat: add http source with support for environment variables

pkg/utils.go

@@ -0,0 +1,93 @@
+package pkg
+
+import (
+	"archive/tar"
+	"compress/gzip"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+func GzipUntar(dst string, r io.Reader, subDir string) error {
+	gzr, err := gzip.NewReader(r)
+	if err != nil {
+		return err
+	}
+	defer gzr.Close()
+
+	tr := tar.NewReader(gzr)
+
+	for {
+		header, err := tr.Next()
+		switch {
+		case err == io.EOF:
+			return nil
+
+		case err != nil:
+			return err
+
+		case header == nil:
+			continue
+		}
+
+		// strip the two first components of the path
+		parts := strings.SplitAfterN(header.Name, "/", 2)
+		if len(parts) < 2 {
+			continue
+		}
+		suffix := parts[1]
+		prefix := dst
+
+		// reconstruct the target parh for the archive entry
+		target := filepath.Join(prefix, suffix)
+
+		// if subdir is provided and target is not under it, skip it
+		subDirPath := filepath.Join(prefix, subDir)
+		if subDir != "" && !strings.HasPrefix(target, subDirPath) {
+			continue
+		}
+
+		// check the file type
+		switch header.Typeflag {
+
+		// create directories as needed
+		case tar.TypeDir:
+			if err := os.MkdirAll(target, os.FileMode(header.Mode)); err != nil {
+				return err
+			}
+
+		case tar.TypeReg:
+			if err := os.MkdirAll(filepath.Dir(target), os.ModePerm); err != nil {
+				return err
+			}
+
+			err := func() error {
+				f, err := os.OpenFile(target, os.O_CREATE|os.O_RDWR, os.FileMode(header.Mode))
+				if err != nil {
+					return err
+				}
+				defer f.Close()
+
+				// copy over contents
+				if _, err := io.Copy(f, tr); err != nil {
+					return err
+				}
+				return nil
+			}()
+
+			if err != nil {
+				return err
+			}
+
+		case tar.TypeSymlink:
+			if err := os.MkdirAll(filepath.Dir(target), os.ModePerm); err != nil {
+				return err
+			}
+
+			if err := os.Symlink(header.Linkname, target); err != nil {
+				return err
+			}
+		}
+	}
+}