examples/unschroot_fs.py: support 0700 homeHEADmain

With the tar backend, there was a chdir(~/.cache/unschroot/...) that
would fail if ~ was lacking execute permission for others. Now we chdir
there before unsharing and then do relative operations to support that
use case.

1 files changed, 8 insertions, 1 deletions

diff --git a/examples/unschroot_fs.py b/examples/unschroot_fs.py
index cda9f93..1c72beb 100755
--- a/examples/unschroot_fs.py
+++ b/examples/unschroot_fs.py
@@ -107,6 +107,9 @@ class SessionChroot(ChrootBase):
         data["Type"] = "unshare"
         return data
 
+    def enter(self) -> None:
+        pass
+
     def mount(self) -> pathlib.Path:
         raise NotImplementedError
 
@@ -185,8 +188,11 @@ class TarSessionChroot(SessionChroot):
         data["Location"] = "/opt"
         return data
 
+    def enter(self) -> None:
+        os.chdir(self.path)
+
     def mount(self) -> pathlib.Path:
-        linuxnamespaces.bind_mount(self.path, "/mnt", recursive=True)
+        linuxnamespaces.bind_mount(".", "/mnt", recursive=True)
         return pathlib.Path("/mnt")
 
 
@@ -364,6 +370,7 @@ def do_run_session(args: argparse.Namespace) -> None:
         for fd in (1, 2):
             if stat.S_ISFIFO(os.fstat(fd).st_mode):
                 os.fchmod(fd, 0o666)
+        session.enter()
         ns = (
             linuxnamespaces.CloneFlags.NEWUSER
             | linuxnamespaces.CloneFlags.NEWNS