def __exit__()

in antlir/unshare.py [0:0]

• 25 lines of code
• 9 McCabe index (conditional complexity)

    def __exit__(self, exc_type, exc_val, exc_tb):
        if self._namespace_to_file is not None:
            # We need to close the files to let the namespaces be destroyed
            for f in self._namespace_to_file.values():
                try:
                    f.close()
                # Covering this realistically seems really hard, since this
                # should never fail. Manual test:
                #
                #   >>> log = logging.getLogger('moo')
                #   >>> f = open('/proc/self/ns/mnt', 'rb')
                #   >>> try:
                #   ...     1/0
                #   ... except:
                #   ...     log.exception(f'Closing namespace file {f.name}')
                #   ...
                #   Closing namespace file /proc/self/ns/mnt
                #   Traceback (most recent call last):
                #     File "<stdin>", line 2, in <module>
                #     ZeroDivisionError: division by zero
                except BaseException:  # pragma: no cover
                    log.exception(f"Closing namespace file {f.name}")
            self._namespace_to_file = None

        try:
            if self._root_fd:
                os.close(self._root_fd)
        # Same coverage story as above for the `f.close()`
        except BaseException:  # pragma: no cover
            log.exception(f"Closing root directory FD {self._root_fd}")
        self._root_fd = None

        if self._keepalive_proc:
            try:
                self._keepalive_proc.stdin.close()  # "Normally" won't fail
                if self._keepalive_proc.wait() != 0:  # prag
                    log.warning(
                        "Unshare keepalive exited with {}".format(
                            self._keepalive_proc.returncode
                        )
                    )
            finally:
                self._keepalive_proc = None