def test__writes_with_lock(self):
lock = FileLock(security.get_shared_secret_filesystem_path())
self.assertFalse(lock.is_locked())
def check_lock(path, data):
self.assertTrue(lock.is_locked())
write_text_file = self.patch_autospec(security, "write_text_file")
write_text_file.side_effect = check_lock
security.set_shared_secret_on_filesystem(b"foo")
self.assertThat(write_text_file, MockCalledOnceWith(ANY, ANY))
self.assertFalse(lock.is_locked())
def test__reads_with_lock(self):
lock = FileLock(security.get_shared_secret_filesystem_path())
self.assertFalse(lock.is_locked())
def check_lock(path):
self.assertTrue(lock.is_locked())
return "12" # Two arbitrary hex characters.
read_text_file = self.patch_autospec(security, "read_text_file")
read_text_file.side_effect = check_lock
security.get_shared_secret_from_filesystem()
self.assertThat(read_text_file, MockCalledOnceWith(ANY))
self.assertFalse(lock.is_locked())
def get_shared_secret_from_filesystem():
"""Load the secret from the filesystem.
`get_shared_secret_filesystem_path` defines where the file will be
written. If the directory does not already exist, this will attempt to
create it, including all parent directories.
:return: A byte string of arbitrary length.
"""
secret_path = get_shared_secret_filesystem_path()
# ensure the parent dir exists so that the lock can be created
secret_path.parent.mkdir(parents=True, exist_ok=True)
with FileLock(secret_path).wait(10):
if not secret_path.exists():
return None
return to_bin(secret_path.read_text())
def set_shared_secret_on_filesystem(secret):
"""Write the secret to the filesystem.
`get_shared_secret_filesystem_path` defines where the file will be
written. If the directory does not already exist, this will attempt to
create it, including all parent directories.
:type secret: A byte string of arbitrary length.
"""
secret_path = get_shared_secret_filesystem_path()
makedirs(dirname(secret_path), exist_ok=True)
secret_hex = to_hex(secret)
with FileLock(secret_path).wait(10):
# Ensure that the file has sensible permissions.
with open(secret_path, "ab") as secret_f:
fchmod(secret_f.fileno(), 0o640)
# Write secret to the filesystem.
write_text_file(secret_path, secret_hex)
def set_shared_secret_on_filesystem(secret):
"""Write the secret to the filesystem.
`get_shared_secret_filesystem_path` defines where the file will be
written. If the directory does not already exist, this will attempt to
create it, including all parent directories.
:type secret: A byte string of arbitrary length.
"""
secret_path = get_shared_secret_filesystem_path()
if secret:
secret_path.parent.mkdir(parents=True, exist_ok=True)
secret_hex = to_hex(secret)
with FileLock(str(secret_path)).wait(10):
secret_path.touch()
secret_path.chmod(0o640)
secret_path.write_text(secret_hex)
elif secret_path.exists():
secret_path.unlink()
def get_shared_secret_from_filesystem():
"""Load the secret from the filesystem.
`get_shared_secret_filesystem_path` defines where the file will be
written. If the directory does not already exist, this will attempt to
create it, including all parent directories.
:return: A byte string of arbitrary length.
"""
secret_path = get_shared_secret_filesystem_path()
makedirs(dirname(secret_path), exist_ok=True)
with FileLock(secret_path).wait(10):
# Load secret from the filesystem, if it exists.
try:
secret_hex = read_text_file(secret_path)
except IOError as e:
if e.errno == errno.ENOENT:
return None
else:
raise
else:
return to_bin(secret_hex)
def test_path(self):
filename = self.make_file()
expected = filename + ".lock"
observed = FileLock(filename).path
self.assertEqual(expected, observed)
