Fix .ssh/config file not being closed (#513)

* Fix .ssh/config file not being closed

The existing parsing logic was very brittle
and did not take into account a possible variantions
(e.g. capitalization, extra white space etc.)
So I switched to a proper parser from aiida-core,
that we already use in this file anyway.

I also discovered other possible bugs in the code,
left them as TODO for future PRs.

* review

* Add links to Github issues

aiidalab_widgets_base/computational_resources.py

@@ -421,12 +421,17 @@ def _can_login(self):
         return ret == 0
 
     def _is_in_config(self):
-        """Check if the config file contains host information."""
+        """Check if the SSH config file contains host information."""
         fpath = Path.home() / ".ssh" / "config"
         if not fpath.exists():
             return False
-        cfglines = open(fpath).read().split("\n")
-        return "Host " + self.hostname.value in cfglines
+        sshcfg = parse_sshconfig(self.hostname.value)
+        # NOTE: parse_sshconfig returns a dict with a hostname
+        # even if it is not in the config file.
+        # We require at least the user to be specified.
+        if "user" not in sshcfg:
+            return False
+        return True
 
     def _write_ssh_config(self, private_key_abs_fname=None):
         """Put host information into the config file."""
@@ -477,8 +482,15 @@ def _on_setup_ssh_button_pressed(self, _=None):
 
             # Write private key in ~/.ssh/ and use the name of upload file,
             # if exist, generate random string and append to filename then override current name.
+            # TODO(danielhollas): I don't think this works as intended. If there is an existing private key,
+            # the new filename is never propagated to the caller here.
+            # https://github.com/aiidalab/aiidalab-widgets-base/issues/516
             self._add_private_key(private_key_abs_fname, private_key_content)
 
+        # TODO(danielhollas): I am not sure this is correct. What if the user wants
+        # to overwrite the private key? Or any other config? The configuration would never be written.
+        # And the user is not notified that we did not write anything.
+        # https://github.com/aiidalab/aiidalab-widgets-base/issues/516
         if not self._is_in_config():
             self._write_ssh_config(private_key_abs_fname=private_key_abs_fname)
 

tests/test_computational_resources.py

@@ -40,8 +40,9 @@ def test_ssh_computer_setup_widget():
     widget.username.value = "aiida"
 
     # Write the information to ~/.ssh/config and check that it is there.
+    assert widget._is_in_config() is False
     widget._write_ssh_config()
-    assert widget._is_in_config()
+    assert widget._is_in_config() is True
 
     # Check that ssh-keygen operation is successful.
     widget._ssh_keygen()