Fix deletion and removal of ssh keys

Closes #7

feudal/backend/migrations/0026_deploymentstate_pending.py

-# Generated by Django 2.1.3 on 2018-11-22 22:15
-
-from django.db import migrations, models
-
-
-class Migration(migrations.Migration):
-
-    dependencies = [
-        ('backend', '0025_auto_20181121_1149'),
-    ]
-
-    operations = [
-        migrations.AddField(
-            model_name='deploymentstate',
-            name='pending',
-            field=models.BooleanField(default=False, editable=False),
-        ),
-    ]

feudal/backend/models/__init__.py

@@ -707,6 +707,7 @@ class CredentialState(models.Model):
     def set(self, state):
         if state == NOT_DEPLOYED and self._credential_deleted:
             self._delete_state()
+            return
 
         if state == self.state:
             return
@@ -720,6 +721,7 @@ class CredentialState(models.Model):
         if self.state == NOT_DEPLOYED:
             self._delete_state()
 
+        LOGGER.debug('related credential: %s', self.credential)
         self.state_target = NOT_DEPLOYED
         self._credential_deleted = True
         self.save()
@@ -729,8 +731,11 @@ class CredentialState(models.Model):
 
     def _delete_state(self):
         LOGGER.debug(self.msg('Deleted'))
+        credential = self.credential
         self.delete()
 
+        credential.try_delete_key()
+
     def msg(self, message):
         return '{} - {}'.format(self, message)
 

feudal/backend/models/users.py

@@ -210,7 +210,7 @@ class User(AbstractUser):
 
         # oidcuser: deploy the according credentials
         if self.user_type == 'oidcuser':
-            #for dep in self.deployments.all():
+            # for dep in self.deployments.all():
             #    dep.activate()
             pass
 
@@ -306,15 +306,13 @@ class User(AbstractUser):
 
             # is the idp key still present?
             if idp_key_name not in userinfo:
-                key.delete_key()
-                self.user_changed_key_removed(key)
+                self.user_remove_key(key)
 
                 return True
 
             # is the idp key changed?
             if key.key != unity_key_value:
-                key.delete_key()
-                self.user_changed_key_removed(key)
+                self.user_remove_key(key)
 
                 new_key = SSHPublicKey(
                     name=unity_key_name,
@@ -376,7 +374,10 @@ class User(AbstractUser):
         for dep in self.deployments.all():
             dep.user_credential_added(key)
 
-    def user_changed_key_removed(self, key):
+    def user_remove_key(self, key):
+        if key.delete_key():
+            return
+
         LOGGER.debug('user_changed_key_removed: %s %s', self, key)
 
         for dep in self.deployments.all():
@@ -424,15 +425,26 @@ class SSHPublicKey(models.Model):
     def value(self):
         return self.key
 
-    # does not really delete the key
+    # returns true if the deletion is final
     def delete_key(self):
-        LOGGER.debug('delete_key: %s', self.name)
+        if self.try_delete_key():
+            return True
+
+        LOGGER.debug(self.msg('Deletion started'))
         self.user = None
         self.key = ''
         self.deleted = True
         self.save()
+        return False
+
+    # if this key has no credential states anymore we _really_ delete it
+    def try_delete_key(self):
+        if not self.credential_states.filter(state='deployed').exists():
+            LOGGER.info(self.msg('Final deletion'))
+            self.delete()
+            return True
 
-        LOGGER.debug('delete_key: need to inform clients about deletion')
+        return False
 
     def __str__(self):
         if self.deleted:

feudal/backend/views/webpage.py

@@ -57,11 +57,7 @@ class SSHPublicKeyView(views.APIView):
                 id=request.data['id'],
             )
 
-            # we do not delete ssh keys directly, as we need to keep track
-            # of them until all clients have also deleted them
-            key.delete_key()
-
-            request.user.user_changed_key_removed(key)
+            request.user.user_remove_key(key)
 
             return Response({
                 'deleted': True,