refactor(terminal): 去掉 Session 中 Terminal 的外键关系

apps/terminal/migrations/0027_auto_20201102_1651.py

@@ -0,0 +1,19 @@
+# Generated by Django 2.2.13 on 2020-11-02 08:51
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('terminal', '0026_auto_20201027_1905'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='session',
+            name='terminal',
+            field=models.ForeignKey(db_constraint=False, null=True, on_delete=django.db.models.deletion.DO_NOTHING, to='terminal.Terminal'),
+        ),
+    ]

apps/terminal/models.py

@@ -198,7 +198,7 @@ class Session(OrgModelMixin):
     is_finished = models.BooleanField(default=False, db_index=True)
     has_replay = models.BooleanField(default=False, verbose_name=_("Replay"))
     has_command = models.BooleanField(default=False, verbose_name=_("Command"))
-    terminal = models.ForeignKey(Terminal, null=True, on_delete=models.SET_NULL)
+    terminal = models.ForeignKey(Terminal, null=True, on_delete=models.DO_NOTHING, db_constraint=False)
     protocol = models.CharField(choices=PROTOCOL.choices, default='ssh', max_length=16, db_index=True)
     date_start = models.DateTimeField(verbose_name=_("Date start"), db_index=True, default=timezone.now)
     date_end = models.DateTimeField(verbose_name=_("Date end"), null=True)