implement user creation in osusers.admin

- add osusers.admin.UserCreationForm
- add dummy osusers.tasks implementation with create_ldap_group and
  create_ldap_user
- fix UserManager.get_next_username
- add proper transaction handling in UserManager.create_user
- add calls to create_ldap_user and create_ldap_group to
  UserManager.create_user

gnuviechadmin/osusers/admin.py

@@ -1,3 +1,5 @@
+from django import forms
+from django.utils.translation import ugettext as _
 from django.contrib import admin
 
 from .models import (
@@ -7,6 +9,8 @@ from .models import (
     User,
 )
 
+PASSWORD_MISMATCH_ERROR = _("Passwords don't match")
+
 
 class AdditionalGroupInline(admin.TabularInline):
     model = AdditionalGroup
@@ -18,9 +22,73 @@ class ShadowInline(admin.TabularInline):
     can_delete = False
 
 
+class UserCreationForm(forms.ModelForm):
+    """
+    A form for creating system users.
+
+    """
+    password1 = forms.CharField(label=_('Password'),
+                                widget=forms.PasswordInput)
+    password2 = forms.CharField(label=_('Password (again)'),
+                                widget=forms.PasswordInput)
+
+    class Meta:
+        model = User
+        fields = []
+
+    def clean_password2(self):
+        """
+        Check that the two password entries match.
+
+        """
+        password1 = self.cleaned_data.get('password1')
+        password2 = self.cleaned_data.get('password2')
+        if password1 and password2 and password1 != password2:
+            raise forms.ValidationError(PASSWORD_MISMATCH_ERROR)
+        return password2
+
+    def save(self, commit=True):
+        """
+        Save the provided password in hashed format.
+
+        """
+        user = User.objects.create_user(
+            password=self.cleaned_data['password1'], commit=commit)
+        return user
+
+    def save_m2m(self):
+        pass
+
+
 class UserAdmin(admin.ModelAdmin):
     inlines = [AdditionalGroupInline, ShadowInline]
     readonly_fields = ['uid']
+    add_form = UserCreationForm
+
+    add_fieldsets = (
+        (None, {
+            'classes': ('wide',),
+            'fields': ('password1', 'password2')}),
+    )
+
+    def get_form(self, request, obj=None, **kwargs):
+        """
+        Use special form during user creation.
+
+        """
+        defaults = {}
+        if obj is None:
+            defaults.update({
+                'form': self.add_form,
+                'fields': admin.util.flatten_fieldsets(self.add_fieldsets),
+            })
+        defaults.update(kwargs)
+        return super(UserAdmin, self).get_form(request, obj, **defaults)
+
+    def get_inline_instances(self, request, obj=None):
+        if obj is None:
+            return []
+        return super(UserAdmin, self).get_inline_instances(request, obj)
 
 
 admin.site.register(Group)