feat: add instance configuration form visible only to admins

dash/admin.py

@@ -1,3 +1,5 @@
 from django.contrib import admin
 
-# Register your models here.
+from .models import InstanceConfiguration
+
+admin.site.register(InstanceConfiguration)

dash/migrations/0001_initial.py

@@ -0,0 +1,52 @@
+# Generated by Django 4.0.3 on 2022-06-17 14:47
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = []
+
+    operations = [
+        migrations.CreateModel(
+            name="InstanceConfiguration",
+            fields=[
+                ("ID", models.AutoField(primary_key=True, serialize=False)),
+                (
+                    "name",
+                    models.CharField(
+                        max_length=32,
+                        unique=True,
+                        verbose_name="Name of this configuration",
+                    ),
+                ),
+                (
+                    "ram",
+                    models.FloatField(
+                        verbose_name="The amount of RAM an instance will have"
+                    ),
+                ),
+                (
+                    "cpu",
+                    models.IntegerField(
+                        verbose_name="The amount of CPU an instance will have"
+                    ),
+                ),
+                (
+                    "storage",
+                    models.FloatField(
+                        verbose_name="The amount of storage an instance will have"
+                    ),
+                ),
+                ("created_at", models.DateTimeField(auto_now_add=True)),
+            ],
+        ),
+        migrations.AddConstraint(
+            model_name="instanceconfiguration",
+            constraint=models.UniqueConstraint(
+                fields=("ram", "cpu", "storage"), name="no_repeat_config"
+            ),
+        ),
+    ]

dash/models.py

@@ -1,3 +1,52 @@
-from django.db import models
+# Copyright © 2022 Aravinth Manivannan <realaravinth@batsense.net>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-# Create your models here.
+from django.db import models
+from django.contrib.auth.models import User
+from django.utils.http import urlencode
+from django.urls import reverse
+
+
+class InstanceConfiguration(models.Model):
+    ID = models.AutoField(primary_key=True)
+    name = models.CharField(
+        "Name of this configuration",
+        unique=True,
+        max_length=32,
+    )
+    ram = models.FloatField(
+        "The amount of RAM an instance will have",
+        null=False,
+    )
+    cpu = models.IntegerField(
+        "The amount of CPU an instance will have",
+        null=False,
+    )
+    storage = models.FloatField(
+        "The amount of storage an instance will have",
+        null=False,
+    )
+
+    created_at = models.DateTimeField(auto_now_add=True, blank=True)
+
+    def __str__(self):
+        return f"{self.name}"
+
+    class Meta:
+        constraints = [
+            models.UniqueConstraint(
+                fields=["ram", "cpu", "storage"], name="no_repeat_config"
+            )
+        ]

dash/tests.py

@@ -16,8 +16,10 @@ from django.contrib.auth import get_user_model
 from django.utils.http import urlencode
 from django.urls import reverse
 from django.test import TestCase, Client, override_settings
-from django.contrib.auth import authenticate
 from django.conf import settings
+from django.db.utils import IntegrityError
+
+from .models import InstanceConfiguration
 
 
 class DashHome(TestCase):
@@ -72,3 +74,27 @@ class DashHome(TestCase):
         self.assertEqual(b"Billing" in resp.content, True)
         self.assertEqual(b"Support" in resp.content, True)
         self.assertEqual(b"Logout" in resp.content, True)
+
+
+class InstancesConfig(TestCase):
+    """
+    Tests InstancesConfig model
+    """
+
+    def test_unique_constraint(self):
+        """
+        Test configuration uniqueness
+        """
+        config1 = InstanceConfiguration(
+            name="test config 1", ram=0.5, cpu=1, storage=0.5
+        )
+        config1.save()
+        config2 = InstanceConfiguration(
+            name="test config 2", ram=0.5, cpu=2, storage=0.5
+        )
+        config2.save()
+        with self.assertRaises(IntegrityError):
+            config3 = InstanceConfiguration(
+                name="test config 3", ram=0.5, cpu=1, storage=0.5
+            )
+            config3.save()