unmount defaults to non-destructive mode

Summary:
This flips the sense of the unmount command; previously
we would default to destroying the mount and associated state,
but this was a bit of a massive sharp edge to our UX.

Now the default is non-destructive and you have to explicitly
pass in `--destroy` to enable destructive mode.

Reviewed By: chadaustin

Differential Revision: D6346013

fbshipit-source-id: ce612e7d8a70540d63217a97f96bc5760f3951af

eden/cli/config.py

@@ -394,7 +394,7 @@ Do you want to run `eden mount %s` instead?''' % (path, path))
         with self.get_thrift_client() as client:
             client.mount(mount_info)
 
-    def unmount(self, path, delete_config=True):
+    def unmount(self, path, delete_config):
         path = os.path.realpath(path)
         with self.get_thrift_client() as client:
             client.unmount(path)

eden/cli/main.py

@@ -166,7 +166,7 @@ def do_unmount(args):
     args.path = normalize_path_arg(args.path)
     config = create_config(args)
     try:
-        return config.unmount(args.path, delete_config=not args.no_forget)
+        return config.unmount(args.path, delete_config=args.destroy)
     except EdenService.EdenError as ex:
         print_stderr('error: {}', ex)
         return 1
@@ -465,11 +465,9 @@ def create_parser():
     unmount_parser = subparsers.add_parser(
         'unmount', help='Unmount a specific client')
     unmount_parser.add_argument(
-        '-n', '--no-forget',
+        '--destroy',
         action='store_true',
-        help='Only unmount the client, without forgetting about its '
-        'configuration.  The client can be re-mounted later using the mount '
-        'command.')
+        help='Permanently delete all state associated with the client.')
     unmount_parser.add_argument(
         'path', help='Path where client should be unmounted from')
     unmount_parser.set_defaults(func=do_unmount)

eden/integration/basic_test.py

@@ -208,8 +208,8 @@ class BasicTest:
                          entries)
         self.assertTrue(self.eden.in_proc_mounts(self.mount))
 
-        # Unmount the client with --no-forget
-        self.eden.run_cmd('unmount', '-n', self.mount)
+        # do a normal user-facing unmount, preserving state
+        self.eden.run_cmd('unmount', self.mount)
 
         self.assertFalse(self.eden.in_proc_mounts(self.mount))
         entries = sorted(os.listdir(self.mount))
@@ -227,10 +227,10 @@ class BasicTest:
             self.assertEqual('foo!\n', f.read(), msg='overlay file is correct')
 
     def test_double_unmount(self):
-        # Test calling "unmount -n" twice.  The second should fail, but edenfs
+        # Test calling "unmount" twice.  The second should fail, but edenfs
         # should still work normally afterwards
-        self.eden.run_cmd('unmount', '-n', self.mount)
-        self.eden.run_unchecked('unmount', '-n', self.mount)
+        self.eden.run_cmd('unmount', self.mount)
+        self.eden.run_unchecked('unmount', self.mount)
 
         # Now remount it with the mount command
         self.eden.run_cmd('mount', self.mount)

eden/integration/lib/edenclient.py

@@ -233,9 +233,9 @@ class EdenFS(object):
 
     def unmount(self, path):
         '''
-        Run "eden unmount <path>"
+        Run "eden unmount --destroy <path>"
         '''
-        self.run_cmd('unmount', path)
+        self.run_cmd('unmount', '--destroy', path)
 
     def in_proc_mounts(self, mount_path):
         '''Gets all eden mounts found in /proc/mounts, and returns