Ensure MkdirAllAndChown also sets perms

Generally if we ever need to change perms of a dir, between versions,
this ensures the permissions actually change when we think it should
change without having to handle special cases if it already existed.

Signed-off-by: Brian Goff <cpuguy83@gmail.com>
(cherry picked from commit edb62a3ace8c4303822a391b38231e577f8c2ee8)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

pkg/idtools/idtools.go

@@ -35,13 +35,13 @@ const (
 
 // MkdirAllAndChown creates a directory (include any along the path) and then modifies
 // ownership to the requested uid/gid.  If the directory already exists, this
-// function will still change ownership to the requested uid/gid pair.
+// function will still change ownership and permissions.
 func MkdirAllAndChown(path string, mode os.FileMode, owner Identity) error {
 	return mkdirAs(path, mode, owner, true, true)
 }
 
 // MkdirAndChown creates a directory and then modifies ownership to the requested uid/gid.
-// If the directory already exists, this function still changes ownership.
+// If the directory already exists, this function still changes ownership and permissions.
 // Note that unlike os.Mkdir(), this function does not return IsExist error
 // in case path already exists.
 func MkdirAndChown(path string, mode os.FileMode, owner Identity) error {
@@ -50,7 +50,7 @@ func MkdirAndChown(path string, mode os.FileMode, owner Identity) error {
 
 // MkdirAllAndChownNew creates a directory (include any along the path) and then modifies
 // ownership ONLY of newly created directories to the requested uid/gid. If the
-// directories along the path exist, no change of ownership will be performed
+// directories along the path exist, no change of ownership or permissions will be performed
 func MkdirAllAndChownNew(path string, mode os.FileMode, owner Identity) error {
 	return mkdirAs(path, mode, owner, true, false)
 }
@@ -234,3 +234,8 @@ func parseSubidFile(path, username string) (ranges, error) {
 
 	return rangeList, s.Err()
 }
+
+// CurrentIdentity returns the identity of the current process
+func CurrentIdentity() Identity {
+	return Identity{UID: os.Getuid(), GID: os.Getegid()}
+}

pkg/idtools/idtools_unix.go

@@ -40,7 +40,7 @@ func mkdirAs(path string, mode os.FileMode, owner Identity, mkAll, chownExisting
 		}
 
 		// short-circuit--we were called with an existing directory and chown was requested
-		return lazyChown(path, owner.UID, owner.GID, stat)
+		return setPermissions(path, mode, owner.UID, owner.GID, stat)
 	}
 
 	if os.IsNotExist(err) {
@@ -71,7 +71,7 @@ func mkdirAs(path string, mode os.FileMode, owner Identity, mkAll, chownExisting
 	// even if it existed, we will chown the requested path + any subpaths that
 	// didn't exist when we called MkdirAll
 	for _, pathComponent := range paths {
-		if err := lazyChown(pathComponent, owner.UID, owner.GID, nil); err != nil {
+		if err := setPermissions(pathComponent, mode, owner.UID, owner.GID, nil); err != nil {
 			return err
 		}
 	}
@@ -213,10 +213,11 @@ func callGetent(database, key string) (io.Reader, error) {
 	return bytes.NewReader(out), nil
 }
 
-// lazyChown performs a chown only if the uid/gid don't match what's requested
+// setPermissions performs a chown/chmod only if the uid/gid don't match what's requested
 // Normally a Chown is a no-op if uid/gid match, but in some cases this can still cause an error, e.g. if the
 // dir is on an NFS share, so don't call chown unless we absolutely must.
-func lazyChown(p string, uid, gid int, stat *system.StatT) error {
+// Likewise for setting permissions.
+func setPermissions(p string, mode os.FileMode, uid, gid int, stat *system.StatT) error {
 	if stat == nil {
 		var err error
 		stat, err = system.Stat(p)
@@ -224,6 +225,11 @@ func lazyChown(p string, uid, gid int, stat *system.StatT) error {
 			return err
 		}
 	}
+	if os.FileMode(stat.Mode()).Perm() != mode.Perm() {
+		if err := os.Chmod(p, mode.Perm()); err != nil {
+			return err
+		}
+	}
 	if stat.UID() == uint32(uid) && stat.GID() == uint32(gid) {
 		return nil
 	}