ssh kitten: A new option :code:--symlink-strategy to control how symlinks are copied to the remote machine

Fixes #5249

docs/changelog.rst

@@ -62,6 +62,9 @@ Detailed list of changes
 - ssh kitten: Allow ssh kitten to work from inside tmux, provided the tmux
   session inherits the correct KITTY env vars (:iss:`5227`)
 
+- ssh kitten: A new option :code:`--symlink-strategy` to control how symlinks
+  are copied to the remote machine (:iss:`5249`)
+
 
 0.25.2 [2022-06-07]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

kittens/ssh/copy.py

@@ -39,6 +39,17 @@ A glob pattern. Files with names matching this pattern are excluded from being
 transferred. Useful when adding directories. Can
 be specified multiple times, if any of the patterns match the file will be
 excluded.
+
+
+--symlink-strategy
+default=preserve
+choices=preserve,resolve,keep-path
+Control what happens if the specified path is a symlink. The default is to preserve
+the symlink, re-creating it on the remote machine. Setting this to :code:`resolve`
+will cause the symlink to be followed and its target used as the file/directory to copy.
+The value of :code:`keep-path` is the same as :code:`resolve` except that the remote
+file path is derived from the symlink's path instead of the path of the symlink's target.
+Note that this option does not apply to symlinks encountered while recursively copying directories.
 '''
 
 
@@ -100,5 +111,9 @@ def parse_copy_instructions(val: str, current_val: Dict[str, str]) -> Iterable[T
         raise CopyCLIError('Specifying a remote location with more than one file is not supported')
     home = home_path()
     for loc in locations:
-        arcname = get_arcname(loc, opts.dest, home)
-        yield str(uuid.uuid4()), CopyInstruction(loc, arcname, tuple(opts.exclude))
+        if opts.symlink_strategy != 'preserve':
+            rp = os.path.realpath(loc)
+        else:
+            rp = loc
+        arcname = get_arcname(rp if opts.symlink_strategy == 'resolve' else loc, opts.dest, home)
+        yield str(uuid.uuid4()), CopyInstruction(rp, arcname, tuple(opts.exclude))

kitty_tests/ssh.py

@@ -106,9 +106,13 @@ print(' '.join(map(str, buf)))'''), lines=13, cols=77)
                 touch('d1/d2/x')
                 touch('d1/d2/w.exclude')
                 os.symlink('d2/x', f'{local_home}/d1/y')
+                os.symlink('simple-file', f'{local_home}/s1')
+                os.symlink('simple-file', f'{local_home}/s2')
 
                 conf = '''\
 copy simple-file
+copy s1
+copy --symlink-strategy=keep-name s2
 copy --dest=a/sfa simple-file
 copy --glob g.*
 copy --exclude */w.* d1
@@ -124,12 +128,14 @@ copy --exclude */w.* d1
                 self.assertTrue(os.path.lexists(f'{remote_home}/{tname}/78'))
                 self.assertTrue(os.path.exists(f'{remote_home}/{tname}/78/xterm-kitty'))
                 self.assertTrue(os.path.exists(f'{remote_home}/{tname}/x/xterm-kitty'))
-                for w in ('simple-file', 'a/sfa'):
+                for w in ('simple-file', 'a/sfa', 's2'):
                     with open(os.path.join(remote_home, w), 'r') as f:
                         self.ae(f.read(), simple_data)
+                    self.assertFalse(os.path.islink(f.name))
                 self.assertTrue(os.path.lexists(f'{remote_home}/d1/y'))
                 self.assertTrue(os.path.exists(f'{remote_home}/d1/y'))
                 self.ae(os.readlink(f'{remote_home}/d1/y'), 'd2/x')
+                self.ae(os.readlink(f'{remote_home}/s1'), 'simple-file')
                 contents = set(files_in(remote_home))
                 contents.discard('.zshrc')  # added by check_bootstrap()
                 # depending on platform one of these is a symlink and hence
@@ -137,7 +143,7 @@ copy --exclude */w.* d1
                 contents.discard(f'{tname}/x/xterm-kitty')
                 contents.discard(f'{tname}/78/xterm-kitty')
                 self.ae(contents, {
-                    'g.1', 'g.2', f'{tname}/kitty.terminfo', 'simple-file', 'd1/d2/x', 'd1/y', 'a/sfa',
+                    'g.1', 'g.2', f'{tname}/kitty.terminfo', 'simple-file', 'd1/d2/x', 'd1/y', 'a/sfa', 's1', 's2',
                     '.local/share/kitty-ssh-kitten/kitty/version', '.local/share/kitty-ssh-kitten/kitty/bin/kitty'
                 })
                 self.ae(len(glob.glob(f'{remote_home}/{tname}/*/xterm-kitty')), 2)