feat: create default VM configurations on initialization

ref:
    [1] https://gitea.hostea.org/Hostea/july-mvp/issues/10#issuecomment-639
    [2] https://gitea.hostea.org/Hostea/july-mvp/issues/10#issuecomment-642
    [3] https://gitea.hostea.org/Hostea/july-mvp/issues/10#issuecomment-643

dash/apps.py

@@ -1,6 +1,25 @@
+# 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/>.
 from django.apps import AppConfig
 
 
 class DashConfig(AppConfig):
     default_auto_field = "django.db.models.BigAutoField"
     name = "dash"
+
+    def ready(self):
+        from .models import InstanceConfiguration
+
+        InstanceConfiguration.create_default_configs()

dash/models.py

@@ -16,6 +16,7 @@
 from django.db import models
 from django.contrib.auth.models import User
 from django.utils.http import urlencode
+from django.db.utils import IntegrityError
 from django.urls import reverse
 
 
@@ -42,6 +43,24 @@ class InstanceConfiguration(models.Model):
 
     created_at = models.DateTimeField(auto_now_add=True, blank=True)
 
+    @classmethod
+    def create_default_configs(cls: "InstanceConfiguration"):
+        configs = [
+            cls(name="s1-2", rent=10, ram=2, cpu=1, storage=10),
+            cls(name="s1-4", rent=20, ram=4, cpu=1, storage=20),
+            cls(name="s1-8", rent=40, ram=8, cpu=2, storage=40),
+        ]
+        for config in configs:
+            print(f"[*] Saving configuration {config.name}")
+            try:
+                config.save()
+            except IntegrityError as db_error:
+                print(f"[!] Configuration {config.name} exists")
+                continue
+            except Exception as e:
+                print(f"[ERROR] {e}")
+                raise e
+
     def __str__(self):
         return f"{self.name}"
 

dash/tests.py

@@ -127,6 +127,34 @@ class InstancesConfig(TestCase):
             )
             config3.save()
 
+    def test_default_configuration_is_loaded(self):
+        """
+        Expects InstancesConfig titled "s1-2", "s1-4" and "s1-8"
+
+        ref: https://gitea.hostea.org/Hostea/july-mvp/issues/10#issuecomment-639
+        """
+
+        InstanceConfiguration.create_default_configs()
+
+        self.assertEqual(
+            InstanceConfiguration.objects.filter(
+                name="s1-2", rent=10, ram=2, cpu=1, storage=10
+            ).exists(),
+            True,
+        )
+        self.assertEqual(
+            InstanceConfiguration.objects.filter(
+                name="s1-4", rent=20, ram=4, cpu=1, storage=20
+            ).exists(),
+            True,
+        )
+        self.assertEqual(
+            InstanceConfiguration.objects.filter(
+                name="s1-8", rent=40, ram=8, cpu=2, storage=40
+            ).exists(),
+            True,
+        )
+
 
 class CreateInstance(TestCase):
     def setUp(self):