Allow validation of Openshift allocations when changing quotas

In combination with changes to `coldfront-plugin-cloud` [1],
a Coldfront patch is added to allow validation of
Openshift allocation change requests (arc).

Currently only one scenario is tested:
If the acr requests for quotas below the current usage of
the project, the user will be sent back to the change
request form with an informative error message.

This feature is possible by leveraging Django formsets
and their built-in custom validation feature [2]

[1] nerc-project/coldfront-plugin-cloud#208
[2] https://docs.djangoproject.com/en/5.1/topics/forms/formsets/#custom-formset-validation

Author: QuanMPhm

Dockerfile

@@ -26,12 +26,14 @@ COPY patches/01_add_api_urls.patch /opt/venv/lib/python3.12/site-packages/
 COPY patches/02_fix_allocation_denied_revoked_PR596.patch /opt/venv/lib/python3.12/site-packages/
 COPY patches/03_add_active_needs_renewal_status.patch /opt/venv/lib/python3.12/site-packages/
 COPY patches/04_add_allocation_change_request_created_signal.patch /opt/venv/lib/python3.12/site-packages/
+COPY patches/05_validate_openshift_quota_change_request.patch /opt/venv/lib/python3.12/site-packages/
 
 RUN cd /opt/venv/lib/python3.12/site-packages && \
     patch -p1 < 01_add_api_urls.patch && \
     patch -p1 < 02_fix_allocation_denied_revoked_PR596.patch && \
     patch -p1 < 03_add_active_needs_renewal_status.patch && \
     patch -p1 < 04_add_allocation_change_request_created_signal.patch
+    patch -p1 < 05_validate_openshift_quota_change_request.patch
 
 # Final Image
 FROM python:3.12-slim-bullseye

patches/05_validate_openshift_quota_change_request.patch

@@ -0,0 +1,84 @@
+diff --git a/coldfront/core/allocation/forms.py b/coldfront/core/allocation/forms.py
+index 9700244..e893e8f 100644
+--- a/coldfront/core/allocation/forms.py
++++ b/coldfront/core/allocation/forms.py
+@@ -1,5 +1,6 @@
+ from django import forms
+ from django.db.models.functions import Lower
++from django.core.exceptions import ValidationError
+ from django.shortcuts import get_object_or_404
+ 
+ from coldfront.core.allocation.models import (Allocation, AllocationAccount,
+@@ -11,6 +12,8 @@ from coldfront.core.project.models import Project
+ from coldfront.core.resource.models import Resource, ResourceType
+ from coldfront.core.utils.common import import_from_settings
+ 
++from coldfront_plugin_cloud import tasks, utils
++
+ ALLOCATION_ACCOUNT_ENABLED = import_from_settings(
+     'ALLOCATION_ACCOUNT_ENABLED', False)
+ ALLOCATION_CHANGE_REQUEST_EXTENSION_DAYS = import_from_settings(
+@@ -201,6 +204,33 @@ class AllocationAttributeChangeForm(forms.Form):
+             allocation_attribute.clean()
+ 
+ 
++class AllocationAttributeChangeFormSet(forms.BaseFormSet):
++    def __init__(self, *args, **kwargs):
++        super().__init__(*args, **kwargs)
++
++    def _validate_openshift_quotas(self):
++        """
++        Performs validation on the OpenShift quotas.
++        For now, only check that current usage is lower than requested quota.
++        """
++        allocation_attribute = AllocationAttribute.objects.get(pk=self.cleaned_data[0].get('pk'))
++        allocation = allocation_attribute.allocation
++        if allocator := tasks.find_allocator(allocation):
++            # Only support Openshift allocations for now
++            if allocator.resource_type == 'openshift':
++                requested_quota = utils.get_new_cloud_quota(self.cleaned_data)
++                cloud_quota_usage = tasks.get_allocation_cloud_usage(allocation.pk)
++                usage_errors = utils.check_cloud_usage_is_lower(requested_quota, cloud_quota_usage)
++
++                if usage_errors:
++                    raise ValidationError(usage_errors)
++
++    def clean(self):
++        if any(self.errors):
++            return
++        self._validate_openshift_quotas()
++
++
+ class AllocationAttributeUpdateForm(forms.Form):
+     change_pk = forms.IntegerField(required=False, disabled=True)
+     attribute_pk = forms.IntegerField(required=False, disabled=True)
+diff --git a/coldfront/core/allocation/views.py b/coldfront/core/allocation/views.py
+index 90f04b8..f5296fe 100644
+--- a/coldfront/core/allocation/views.py
++++ b/coldfront/core/allocation/views.py
+@@ -28,6 +28,7 @@ from coldfront.core.allocation.forms import (AllocationAccountForm,
+                                              AllocationChangeForm,
+                                              AllocationChangeNoteForm,
+                                              AllocationAttributeChangeForm,
++                                             AllocationAttributeChangeFormSet,
+                                              AllocationAttributeUpdateForm,
+                                              AllocationForm,
+                                              AllocationInvoiceNoteDeleteForm,
+@@ -1786,7 +1787,7 @@ class AllocationChangeView(LoginRequiredMixin, UserPassesTestMixin, FormView):
+ 
+         if allocation_attributes_to_change:
+             formset = formset_factory(self.formset_class, max_num=len(
+-                allocation_attributes_to_change))
++                allocation_attributes_to_change), formset=AllocationAttributeChangeFormSet)
+             formset = formset(
+                 request.POST, initial=allocation_attributes_to_change, prefix='attributeform')
+ 
+@@ -1796,6 +1797,8 @@ class AllocationChangeView(LoginRequiredMixin, UserPassesTestMixin, FormView):
+                     messages.error(request, error)
+                 for error in formset.errors:
+                     if error: attribute_errors += error.get('__all__')
++                for error in formset.non_form_errors():
++                    messages.error(request, error)
+                 messages.error(request, attribute_errors)
+                 return HttpResponseRedirect(reverse('allocation-change', kwargs={'pk': pk}))
+             form_data = form.cleaned_data