Revamp virtual environments (now reusable!)

Venvs are no longer associated with assignments; instead, assignments can now use a venv to run submissions

tin/apps/assignments/forms.py

@@ -31,6 +31,7 @@ class Meta:
             "folder",
             "language",
             "filename",
+            "venv",
             "points_possible",
             "due",
             "hidden",
@@ -43,6 +44,7 @@ class Meta:
             "submission_limit_cooldown",
         ]
         labels = {
+            "venv": "Virtual environment",
             "hidden": "Hide assignment from students?",
             "enable_grader_timeout": "Set a timeout for the grader?",
             "grader_timeout": "Grader timeout (seconds):",
@@ -57,6 +59,7 @@ class Meta:
             "filename": "Clarify which file students need to upload (including the file "
             "extension). For Java assignments, this also sets the name of the "
             "saved submission file.",
+            "venv": "If set, Tin will run the student's code in this virtual environment.",
             "grader_has_network_access": 'If unset, this effectively disables "Give submissions '
             'internet access" below. If set, it increases the amount '
             "of time it takes to start up the grader (to about 1.5 "

tin/apps/assignments/migrations/0028_assignment_venv.py

@@ -0,0 +1,20 @@
+# Generated by Django 3.2.25 on 2024-03-29 05:12
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('venvs', '0005_auto_20240328_0033'),
+        ('assignments', '0027_mossresult'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='assignment',
+            name='venv',
+            field=models.ForeignKey(blank=True, default=None, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='assignments', to='venvs.venv'),
+        ),
+    ]

tin/apps/assignments/models.py

@@ -15,7 +15,7 @@
 from ...sandboxing import get_action_sandbox_args, get_assignment_sandbox_args
 from ..courses.models import Course, Period
 from ..submissions.models import Submission
-from ..venvs.models import Virtualenv
+from ..venvs.models import Venv
 
 logger = logging.getLogger(__name__)
 
@@ -85,6 +85,15 @@ class Assignment(models.Model):
         "courses.Course", on_delete=models.CASCADE, related_name="assignments"
     )
 
+    venv = models.ForeignKey(
+        Venv,
+        on_delete=models.SET_NULL,
+        default=None,
+        null=True,
+        blank=True,
+        related_name="assignments",
+    )
+
     points_possible = models.DecimalField(
         max_digits=6, decimal_places=3, validators=[MinValueValidator(1)]
     )
@@ -256,13 +265,9 @@ def check_rate_limit(self, student) -> None:
                     current_cooldown.delete()
                 CooldownPeriod.objects.create(assignment=self, student=student)
 
-    @property
-    def venv_object_created(self):
-        return Virtualenv.objects.filter(assignment=self).exists()
-
     @property
     def venv_fully_created(self):
-        return Virtualenv.objects.filter(assignment=self, fully_created=True).exists()
+        return self.venv and self.venv.fully_created
 
     @property
     def grader_log_filename(self):

tin/apps/submissions/tasks.py

@@ -62,7 +62,7 @@ def run_submission(submission_id):
             raise FileNotFoundError from e
 
         python_exe = (
-            os.path.join(submission.assignment.venv.get_full_path(), "bin/python")
+            os.path.join(submission.assignment.venv.path, "bin", "python")
             if submission.assignment.venv_fully_created
             else "/usr/bin/python3.10"
         )
@@ -84,7 +84,7 @@ def run_submission(submission_id):
             wrapper_text = wrapper_file.read().format(
                 has_network_access=bool(submission.assignment.has_network_access),
                 venv_path=(
-                    submission.assignment.venv.get_full_path()
+                    submission.assignment.venv.path
                     if submission.assignment.venv_fully_created
                     else None
                 ),
@@ -132,8 +132,8 @@ def run_submission(submission_id):
         if not settings.DEBUG or shutil.which("firejail") is not None:
             whitelist = [os.path.dirname(grader_path)]
             read_only = [grader_path, submission_path, os.path.dirname(submission_wrapper_path)]
-            if submission.assignment.venv_object_created:
-                read_only.append(submission.assignment.venv.get_full_path())
+            if submission.assignment.venv_fully_created:
+                read_only.append(submission.assignment.venv.path)
 
             args = sandboxing.get_assignment_sandbox_args(
                 args,

tin/apps/venvs/admin.py

@@ -1,14 +1,13 @@
 from django.contrib import admin
 
-from .models import Virtualenv
+from .models import Venv
 
 # Register your models here.
 
 
-@admin.register(Virtualenv)
-class VirtualenvAdmin(admin.ModelAdmin):
-    list_display = ("assignment", "fully_created", "installing_packages")
+@admin.register(Venv)
+class VenvAdmin(admin.ModelAdmin):
+    list_display = ("name", "fully_created", "installing_packages")
     list_filter = ("fully_created", "installing_packages")
     save_as = True
-    search_fields = ("assignment__name",)
-    autocomplete_fields = ("assignment",)
+    search_fields = ("name",)

tin/apps/venvs/forms.py

@@ -0,0 +1,9 @@
+from django import forms
+
+from .models import Venv
+
+
+class VenvForm(forms.ModelForm):
+    class Meta:
+        model = Venv
+        fields = ["name"]

tin/apps/venvs/migrations/0005_auto_20240328_0033.py

@@ -0,0 +1,26 @@
+# Generated by Django 3.2.25 on 2024-03-28 04:33
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('venvs', '0004_alter_virtualenv_id'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='Venv',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('name', models.CharField(max_length=255)),
+                ('fully_created', models.BooleanField()),
+                ('installing_packages', models.BooleanField(default=False)),
+                ('package_installation_output', models.CharField(blank=True, default='', max_length=16384)),
+            ],
+        ),
+        migrations.DeleteModel(
+            name='Virtualenv',
+        ),
+    ]

tin/apps/venvs/models.py

@@ -12,111 +12,55 @@
 logger = logging.getLogger(__name__)
 
 
-class VirtualenvCreationError(Exception):
+class VenvCreationError(Exception):
     pass
 
 
-class VirtualenvExistsError(VirtualenvCreationError):
+class VenvExistsError(VenvCreationError):
     pass
 
 
 class VenvQuerySet(models.query.QuerySet):
     def filter_visible(self, user):
-        if user.is_superuser:
+        if user.is_superuser or user.is_teacher:
             return self.all()
-        else:
-            return self.filter(assignment__course__teacher=user).distinct()
+        return self.none()
 
     def filter_editable(self, user):
         if user.is_superuser:
             return self.all()
-        else:
-            return self.filter(assignment__course__teacher=user).distinct()
+        return self.none()
 
 
-class Virtualenv(models.Model):
+class Venv(models.Model):
     objects = VenvQuerySet.as_manager()
 
-    assignment = models.OneToOneField(
-        "assignments.Assignment", on_delete=models.CASCADE, related_name="venv", null=False
-    )
+    name = models.CharField(max_length=255, null=False, blank=False)
 
     fully_created = models.BooleanField(null=False)
 
     installing_packages = models.BooleanField(default=False, null=False)
 
+    OUTPUT_MAX_LENGTH = 16 * 1024
     package_installation_output = models.CharField(
-        max_length=16 * 1024, default="", null=False, blank=True
+        max_length=OUTPUT_MAX_LENGTH, default="", null=False, blank=True
     )
 
     def __str__(self):
-        return f"Virtualenv for {self.assignment}"
+        return self.name
 
     def __repr__(self):
-        return f"Virtualenv for {self.assignment}"
+        return f"<Virtualenv: {self.name}>"
 
     def get_absolute_url(self):
         return reverse("venvs:show", args=[self.id])
 
-    def get_full_path(self):
-        assert self.assignment.grader_file.name
-        return os.path.join(
-            settings.MEDIA_ROOT, os.path.dirname(self.assignment.grader_file.name), "venv"
-        )
-
-    @classmethod
-    def create_venv_for_assignment(cls, assignment):
-        try:
-            venv = cls.objects.create(assignment=assignment, fully_created=False)
-        except IntegrityError:
-            raise VirtualenvExistsError
-
-        success = False
-
-        try:
-            if os.path.exists(venv.get_full_path()):
-                raise VirtualenvCreationError(
-                    "Virtualenv directory for assignment #{} exists".format(assignment.id)
-                )
-
-            try:
-                res = subprocess.run(
-                    [
-                        sys.executable,
-                        "-m",
-                        "virtualenv",
-                        "-p",
-                        settings.SUBMISSION_PYTHON,
-                        "--",
-                        venv.get_full_path(),
-                    ],
-                    check=False,
-                    stdin=subprocess.DEVNULL,
-                    stdout=subprocess.PIPE,
-                    stderr=subprocess.STDOUT,
-                )
-            except FileNotFoundError as e:
-                logger.error("Cannot run processes: %s", e)
-                raise FileNotFoundError from e
-
-            if res.returncode != 0:
-                raise VirtualenvCreationError(
-                    "Error creating virtual environment (return code {}): {}".format(
-                        res.returncode, res.stdout
-                    )
-                )
-
-            venv.fully_created = True
-            venv.save()
-            success = True
-        finally:
-            if not success:
-                venv.delete()
-
-        return venv
+    @property
+    def path(self):
+        return os.path.join(settings.MEDIA_ROOT, "venvs", f"venv-{self.id}")
 
     def get_activation_env(self):
-        venv_path = self.get_full_path()
+        venv_path = self.path
 
         return {
             "VIRTUAL_ENV": venv_path,
@@ -130,7 +74,7 @@ def list_packages(self):
         args = sandboxing.get_assignment_sandbox_args(
             ["pip", "freeze"],
             network_access=False,
-            read_only=[self.get_full_path()],
+            read_only=[self.path],
             extra_firejail_args=["--rlimit-fsize=209715200"],
         )
 
@@ -168,7 +112,7 @@ def install_packages(self, pkgs):
             args = sandboxing.get_assignment_sandbox_args(
                 ["pip", "install", "--upgrade", "--", *pkgs],
                 network_access=True,
-                whitelist=[self.get_full_path()],
+                whitelist=[self.path],
                 extra_firejail_args=["--rlimit-fsize=209715200"],
             )
 
@@ -186,9 +130,9 @@ def install_packages(self, pkgs):
                 raise FileNotFoundError from e
 
             try:
-                self.package_installation_output = res.stdout.decode()[-16 * 1024:]
+                self.package_installation_output = res.stdout.decode()[-self.OUTPUT_MAX_LENGTH:]
             except UnicodeDecodeError:
-                self.package_installation_output = str(res.stdout)[-16 * 1024:]
+                self.package_installation_output = str(res.stdout)[-self.OUTPUT_MAX_LENGTH:]
         finally:
             self.installing_packages = False
             self.save()

tin/apps/venvs/tasks.py

@@ -1,24 +1,59 @@
+import logging
+import subprocess
+import sys
+
 from celery import shared_task
 
-from ..assignments.models import Assignment
-from .models import Virtualenv, VirtualenvCreationError
+from django.conf import settings
 
+from .models import Venv, VenvCreationError, VenvExistsError
 
-@shared_task
-def create_virtualenv(assignment_id):
-    assignment = Assignment.objects.get(id=assignment_id)
+logger = logging.getLogger(__name__)
 
-    if assignment.venv_object_created:
-        return
 
+@shared_task
+def create_venv(venv_id):
+    venv = Venv.objects.get(id=venv_id)
+
+    success = False
     try:
-        Virtualenv.create_venv_for_assignment(assignment)
-    except VirtualenvCreationError:
-        pass
+        try:
+            res = subprocess.run(
+                [
+                    sys.executable,
+                    "-m",
+                    "virtualenv",
+                    "-p",
+                    settings.SUBMISSION_PYTHON,
+                    "--",
+                    venv.path,
+                ],
+                check=False,
+                stdin=subprocess.DEVNULL,
+                stdout=subprocess.PIPE,
+                stderr=subprocess.STDOUT,
+            )
+        except FileNotFoundError as e:
+            logger.error("Cannot run processes: %s", e)
+            raise FileNotFoundError from e
+
+        if res.returncode != 0:
+            raise VenvCreationError(
+                "Error creating virtual environment (return code {}): {}".format(
+                    res.returncode, res.stdout
+                )
+            )
+
+        venv.fully_created = True
+        venv.save()
+        success = True
+    finally:
+        if not success:
+            venv.delete()
 
 
 @shared_task
 def install_packages(venv_id, package_names):
-    venv = Virtualenv.objects.get(id=venv_id)
+    venv = Venv.objects.get(id=venv_id)
 
     venv.install_packages(package_names)