uninstall: limit cleanup to s.Target

This was specific to when s.Target differs from /. The helpers creating
the path were considering the full traversal, instead they should stop
at target.

E.g. our rootfs is in /foo/bar, and while we build the list of paths to
prune for /foo/bar/baz/bar, we should stop looking at /foo/bar.

pkg/helpers/archive.go

@@ -23,6 +23,7 @@ import (
 	"path/filepath"
 
 	"github.com/docker/docker/pkg/archive"
+	"github.com/pkg/errors"
 )
 
 func Tar(src, dest string) error {
@@ -131,7 +132,7 @@ func unTarIgnoreOwner(dest string, in io.ReadCloser, mods map[string]archive.Tar
 			if ok {
 				header, data, err = modifier(header.Name, header, tr)
 				if err != nil {
-					return err
+					return errors.Wrap(err, "running modifier wrapper")
 				}
 
 				// Override target path
@@ -157,7 +158,7 @@ func unTarIgnoreOwner(dest string, in io.ReadCloser, mods map[string]archive.Tar
 
 			f, err := os.OpenFile(target, os.O_CREATE|os.O_RDWR, os.FileMode(header.Mode))
 			if err != nil {
-				return err
+				return errors.Wrap(err, "creating destination")
 			}
 
 			// copy over contents
@@ -188,12 +189,11 @@ tarEof:
 }
 
 // Untar just a wrapper around the docker functions
-func Untar(src, dest string, sameOwner bool) error {
-	var ans error
+func Untar(src, dest string, sameOwner bool) (err error) {
 
 	in, err := os.Open(src)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "while opening "+src+" for untar ")
 	}
 	defer in.Close()
 
@@ -204,10 +204,14 @@ func Untar(src, dest string, sameOwner bool) error {
 			ContinueOnError: true,
 		}
 
-		ans = archive.Untar(in, dest, opts)
+		err = archive.Untar(in, dest, opts)
 	} else {
-		ans = unTarIgnoreOwner(dest, in, nil)
+		err = unTarIgnoreOwner(dest, in, nil)
 	}
 
-	return ans
+	if err != nil {
+		err = errors.Wrap(err, "while untarring "+src+" into "+dest)
+	}
+
+	return
 }

pkg/installer/installer.go

@@ -902,7 +902,7 @@ func (l *LuetInstaller) installPackage(m ArtifactMatch, s *System) error {
 
 	err = a.Unpack(l.Options.Context, s.Target, true)
 	if err != nil && !l.Options.Force {
-		return errors.Wrap(err, "Error met while unpacking rootfs")
+		return errors.Wrap(err, "error met while unpacking package "+a.Path)
 	}
 
 	// First create client and download
@@ -950,10 +950,14 @@ func (l *LuetInstaller) installerWorker(i int, wg *sync.WaitGroup, c <-chan Arti
 	return nil
 }
 
-func checkAndPrunePath(ctx *types.Context, path string) {
+func checkAndPrunePath(ctx *types.Context, target, path string) {
 	// check if now the target path is empty
 	targetPath := filepath.Dir(path)
 
+	if target == targetPath {
+		return
+	}
+
 	fi, err := os.Lstat(targetPath)
 	if err != nil {
 		//	l.Options.Context.Warning("Dir not found (it was before?) ", err.Error())
@@ -978,8 +982,8 @@ func checkAndPrunePath(ctx *types.Context, path string) {
 }
 
 // We will try to cleanup every path from the file, if the folders left behind are empty
-func pruneEmptyFilePath(ctx *types.Context, path string) {
-	checkAndPrunePath(ctx, path)
+func pruneEmptyFilePath(ctx *types.Context, target string, path string) {
+	checkAndPrunePath(ctx, target, path)
 
 	// A path is for e.g. /usr/bin/bar
 	// we want to create an array
@@ -987,14 +991,19 @@ func pruneEmptyFilePath(ctx *types.Context, path string) {
 	// excluding the target (in the case above was /)
 	paths := strings.Split(path, string(os.PathSeparator))
 	currentPath := filepath.Join(string(os.PathSeparator), paths[0])
-	allPaths := []string{currentPath}
+	allPaths := []string{}
+	if strings.HasPrefix(currentPath, target) && target != currentPath {
+		allPaths = append(allPaths, currentPath)
+	}
 	for _, p := range paths[1:] {
 		currentPath = filepath.Join(currentPath, p)
-		allPaths = append(allPaths, currentPath)
+		if strings.HasPrefix(currentPath, target) && target != currentPath {
+			allPaths = append(allPaths, currentPath)
+		}
 	}
 	match.ReverseAny(allPaths)
 	for _, p := range allPaths {
-		checkAndPrunePath(ctx, p)
+		checkAndPrunePath(ctx, target, p)
 	}
 }
 
@@ -1058,9 +1067,11 @@ func (l *LuetInstaller) uninstall(p pkg.Package, s *System) error {
 
 		if err = os.Remove(target); err != nil {
 			l.Options.Context.Warning("Failed removing file (maybe not present in the system target anymore ?)", target, err.Error())
+		} else {
+			l.Options.Context.Debug("Removed", target)
 		}
 
-		pruneEmptyFilePath(l.Options.Context, target)
+		pruneEmptyFilePath(l.Options.Context, s.Target, target)
 	}
 
 	for _, f := range notPresent {
@@ -1073,9 +1084,11 @@ func (l *LuetInstaller) uninstall(p pkg.Package, s *System) error {
 
 		if err = os.Remove(target); err != nil {
 			l.Options.Context.Debug("Failed removing file (not present in the system target)", target, err.Error())
+		} else {
+			l.Options.Context.Debug("Removed", target)
 		}
 
-		pruneEmptyFilePath(l.Options.Context, target)
+		pruneEmptyFilePath(l.Options.Context, s.Target, target)
 	}
 
 	err = s.Database.RemovePackageFiles(p)