ansible: _remote_chmod() / _fixup_perms2() can be called sometimes.

It's used at least by the copy module, even though the result is still
mostly a no-op. _remote_chmod() doesn't accept octal mode, it accepts
symbolic mode. So implement a symbolic parser in helpers.py.

ansible_mitogen/connection/mitogen.py

@@ -197,8 +197,8 @@ class Connection(ansible.plugins.connection.ConnectionBase):
         :returns:
             (return code, stdout bytes, stderr bytes)
         """
-        return self.py_call(ansible_mitogen.helpers.exec_command,
+        return self.call(ansible_mitogen.helpers.exec_command,
-                            cast(cmd), cast(in_data))
+                         cast(cmd), cast(in_data))
 
     def fetch_file(self, in_path, out_path):
         """
@@ -210,8 +210,8 @@ class Connection(ansible.plugins.connection.ConnectionBase):
         :param str out_path:
             Local filesystem path to write.
         """
-        output = self.py_call(ansible_mitogen.helpers.read_path,
+        output = self.call(ansible_mitogen.helpers.read_path,
-                              cast(in_path))
+                           cast(in_path))
         ansible_mitogen.helpers.write_path(out_path, output)
 
     def put_file(self, in_path, out_path):
@@ -224,5 +224,5 @@ class Connection(ansible.plugins.connection.ConnectionBase):
         :param str out_path:
             Remote filesystem path to write.
         """
-        self.py_call(ansible_mitogen.helpers.write_path, cast(out_path),
+        self.call(ansible_mitogen.helpers.write_path, cast(out_path),
-                     ansible_mitogen.helpers.read_path(in_path))
+                  ansible_mitogen.helpers.read_path(in_path))

ansible_mitogen/helpers.py

@@ -26,8 +26,11 @@
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 import json
+import operator
 import os
 import pwd
+import re
+import stat
 import subprocess
 import time
 
@@ -165,3 +168,59 @@ def write_path(path, s):
     Writes bytes `s` to a filesystem `path`.
     """
     open(path, 'wb').write(s)
+
+
+
+CHMOD_CLAUSE_PAT = re.compile(r'([uoga]?)([+\-=])([ugo]|[rwx]*)')
+CHMOD_MASKS = {
+    'u': stat.S_IRWXU,
+    'g': stat.S_IRWXG,
+    'o': stat.S_IRWXO,
+    'a': (stat.S_IRWXU | stat.S_IRWXG | stat.S_IRWXO),
+}
+CHMOD_BITS = {
+    'u': {'r':stat.S_IRUSR, 'w':stat.S_IWUSR, 'x':stat.S_IXUSR},
+    'g': {'r':stat.S_IRGRP, 'w':stat.S_IWGRP, 'x':stat.S_IXGRP},
+    'o': {'r':stat.S_IROTH, 'w':stat.S_IWOTH, 'x':stat.S_IXOTH},
+    'a': {
+        'r': (stat.S_IRUSR | stat.S_IRGRP | stat.S_IROTH),
+        'w': (stat.S_IWUSR | stat.S_IWGRP | stat.S_IWOTH),
+        'x': (stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH)
+    }
+}
+
+def or_(it):
+    return reduce(operator.or_, it, 0)
+
+
+def apply_mode_spec(spec, mode):
+    for clause in spec.split(','):
+        match = CHMOD_CLAUSE_PAT.match(clause)
+        who, op, perms = match.groups()
+        mask = CHMOD_MASKS[who]
+        bits = CHMOD_BITS[who]
+        for ch in who or 'a':
+            cur_perm_bits = mode & mask
+            new_perm_bits = or_(bits[p] for p in perms)
+            mode &= ~mask
+            if op == '=':
+                mode |= new_perm_bits
+            elif op == '+':
+                mode |= new_perm_bits | cur_per_bits
+            else:
+                mode |= cur_perm_bits & ~new_perm_bits
+    return mode
+
+
+def set_file_mode(path, spec):
+    """
+    Update the permissions of a file using the same syntax as chmod(1).
+    """
+    mode = os.stat(path).st_mode
+
+    if spec.is_digit():
+        new_mode = int(spec, 8)
+    else:
+        new_mode = apply_mode_spec(spec, mode)
+
+    os.chmod(path, new_mode)

ansible_mitogen/mixins.py

@@ -117,11 +117,14 @@ class ActionModuleMixin(ansible.plugins.action.ActionBase):
 
     def _fixup_perms2(self, remote_paths, remote_user=None, execute=True):
         # replaces 83 lines
-        assert False, "_fixup_perms2() should never be called."
+        if not execute:
+            return self._remote_chmod(remote_paths, mode='u+x')
+        # Do nothing unless request was to set the execute bit.
+        return self.COMMAND_RESULT.copy()
 
     def _remote_chmod(self, paths, mode, sudoable=False):
         return self.fake_shell(lambda: mitogen.master.Select.all(
-            self._connection.call_async(os.chmod, path, mode)
+            self._connection.call_async(helpers.set_file_mode, path, mode)
             for path in paths
         ))