Allow workstation editors to launch debug sessions (#2772)

This PR allows workstation editors to set the region and add extra
environment variables for a new session. Limitation is that the editor
cannot have more than 1 session running to prevent flooding of the
server and confusion about env vars being passed, so they may have to
wait for a workstation session to finish.

Workstation detail view:

![image](https://user-images.githubusercontent.com/12661555/218788675-ed5c4ad2-f8d5-4791-a7dd-c810b93df830.png)

The form (with validation):

![image](https://user-images.githubusercontent.com/12661555/218788497-212c1576-71eb-4389-b6a6-9fbd7a7b7ec4.png)

The env vars being passed:

![image](https://user-images.githubusercontent.com/12661555/218788938-ed628d46-0287-493e-b3ae-5781b1928b6d.png)

Note that the env vars editors set here are used as the default
environment variables, we will overwrite some keys if editors try to set
them (e.g. `GRAND_CHALLENGE_UNSAFE`, `GRAND_CHALLENGE_AUTHORIZATION`,
`GRAND_CHALLENGE_API_ROOT`). Editors can only create debug sessions for
themselves so should be safe.

Also removes `WORKSTATIONS_DNS_RESOLVER` which is no longer used.

Old style forms and tests are used for consistency with the rest of the
workstations application.

app/config/settings.py

@@ -1062,9 +1062,6 @@
 DEFAULT_WORKSTATION_SLUG = os.environ.get(
     "DEFAULT_WORKSTATION_SLUG", "cirrus-core"
 )
-WORKSTATIONS_DNS_RESOLVER = os.environ.get(
-    "WORKSTATIONS_DNS_RESOLVER", "1.1.1.1"
-)
 WORKSTATIONS_BASE_IMAGE_QUERY_PARAM = "image"
 WORKSTATIONS_OVERLAY_QUERY_PARAM = "overlay"
 WORKSTATIONS_READY_STUDY_QUERY_PARAM = "readerStudy"

app/grandchallenge/workstations/admin.py

@@ -37,6 +37,7 @@ class SessionHistoryAdmin(SimpleHistoryAdmin):
         "creator",
         "region",
         "ping_times",
+        "extra_env_vars",
     ]
     list_filter = ["status", "region", "workstation_image__workstation__slug"]
     readonly_fields = [
@@ -47,6 +48,7 @@ class SessionHistoryAdmin(SimpleHistoryAdmin):
         "region",
         "ping_times",
         "auth_token",
+        "extra_env_vars",
     ]
     search_fields = [
         "logs",

app/grandchallenge/workstations/forms.py

@@ -1,10 +1,13 @@
 from crispy_forms.helper import FormHelper
 from django.conf import settings
+from django.core.exceptions import ValidationError
 from django.forms import ChoiceField, HiddenInput, ModelChoiceField, ModelForm
 
 from grandchallenge.components.forms import ContainerImageForm
 from grandchallenge.core.forms import SaveFormInitMixin
+from grandchallenge.core.widgets import JSONEditorWidget
 from grandchallenge.workstations.models import (
+    ENV_VARS_SCHEMA,
     Session,
     Workstation,
     WorkstationImage,
@@ -60,3 +63,46 @@ def __init__(self, *args, **kwargs):
     class Meta:
         model = Session
         fields = ("region", "ping_times")
+
+
+class DebugSessionForm(SaveFormInitMixin, ModelForm):
+    region = ChoiceField(
+        required=True,
+        choices=[
+            c
+            for c in Session.Region.choices
+            if c[0] in settings.WORKSTATIONS_ACTIVE_REGIONS
+        ],
+    )
+
+    def __init__(self, *args, user, workstation, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.__user = user
+        self.__workstation = workstation
+        self.fields["extra_env_vars"].initial = [
+            {"name": "LOG_LEVEL", "value": "DEBUG"},
+            {"name": "CIRRUS_PROFILING_ENABLED", "value": "True"},
+        ]
+
+    def clean(self):
+        cleaned_data = super().clean()
+
+        if Session.objects.filter(
+            creator=self.__user,
+            workstation_image__workstation=self.__workstation,
+            status__in=[Session.QUEUED, Session.STARTED, Session.RUNNING],
+            region=cleaned_data["region"],
+        ).exists():
+            raise ValidationError(
+                "You already have a running workstation in the selected "
+                "region, please wait for that session to finish"
+            )
+
+        return cleaned_data
+
+    class Meta:
+        model = Session
+        fields = ("region", "extra_env_vars")
+        widgets = {
+            "extra_env_vars": JSONEditorWidget(schema=ENV_VARS_SCHEMA),
+        }

app/grandchallenge/workstations/migrations/0016_auto_20230214_1453.py

@@ -0,0 +1,110 @@
+# Generated by Django 3.2.18 on 2023-02-14 14:53
+
+from django.db import migrations, models
+
+import grandchallenge.core.validators
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        (
+            "workstations",
+            "0015_feedbackgroupobjectpermission_feedbackuserobjectpermission_sessiongroupobjectpermission_sessionusero",
+        ),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="historicalsession",
+            name="extra_env_vars",
+            field=models.JSONField(
+                blank=True,
+                default=list,
+                help_text="Extra environment variables to include in this session",
+                validators=[
+                    grandchallenge.core.validators.JSONValidator(
+                        schema={
+                            "$schema": "http://json-schema.org/draft-06/schema",
+                            "description": "Defines environment variable names and values",
+                            "items": {
+                                "$id": "#/items",
+                                "additionalProperties": False,
+                                "description": "Defines an environment variable",
+                                "properties": {
+                                    "name": {
+                                        "$id": "#/items/properties/name",
+                                        "default": "ENV_VAR",
+                                        "description": "The name of this environment variable",
+                                        "examples": ["ENV_VAR"],
+                                        "pattern": "^[A-Z0-9\\_]+$",
+                                        "title": "The Name Schema",
+                                        "type": "string",
+                                    },
+                                    "value": {
+                                        "$id": "#/items/properties/value",
+                                        "default": "env_var_value",
+                                        "description": "The value of this environment variable",
+                                        "examples": ["env_var_value"],
+                                        "title": "The Value Schema",
+                                        "type": "string",
+                                    },
+                                },
+                                "required": ["name", "value"],
+                                "title": "The Environment Variable Schema",
+                                "type": "object",
+                            },
+                            "title": "The Environment Variables Schema",
+                            "type": "array",
+                        }
+                    )
+                ],
+            ),
+        ),
+        migrations.AddField(
+            model_name="session",
+            name="extra_env_vars",
+            field=models.JSONField(
+                blank=True,
+                default=list,
+                help_text="Extra environment variables to include in this session",
+                validators=[
+                    grandchallenge.core.validators.JSONValidator(
+                        schema={
+                            "$schema": "http://json-schema.org/draft-06/schema",
+                            "description": "Defines environment variable names and values",
+                            "items": {
+                                "$id": "#/items",
+                                "additionalProperties": False,
+                                "description": "Defines an environment variable",
+                                "properties": {
+                                    "name": {
+                                        "$id": "#/items/properties/name",
+                                        "default": "ENV_VAR",
+                                        "description": "The name of this environment variable",
+                                        "examples": ["ENV_VAR"],
+                                        "pattern": "^[A-Z0-9\\_]+$",
+                                        "title": "The Name Schema",
+                                        "type": "string",
+                                    },
+                                    "value": {
+                                        "$id": "#/items/properties/value",
+                                        "default": "env_var_value",
+                                        "description": "The value of this environment variable",
+                                        "examples": ["env_var_value"],
+                                        "title": "The Value Schema",
+                                        "type": "string",
+                                    },
+                                },
+                                "required": ["name", "value"],
+                                "title": "The Environment Variable Schema",
+                                "type": "object",
+                            },
+                            "title": "The Environment Variables Schema",
+                            "type": "array",
+                        }
+                    )
+                ],
+            ),
+        ),
+    ]

app/grandchallenge/workstations/models.py

@@ -29,6 +29,7 @@
     protected_s3_storage,
     public_s3_storage,
 )
+from grandchallenge.core.validators import JSONValidator
 from grandchallenge.subdomains.utils import reverse
 from grandchallenge.workstations.emails import send_new_feedback_email_to_staff
 
@@ -271,6 +272,41 @@ class WorkstationImageGroupObjectPermission(GroupObjectPermissionBase):
     )
 
 
+ENV_VARS_SCHEMA = {
+    "$schema": "http://json-schema.org/draft-06/schema",
+    "type": "array",
+    "title": "The Environment Variables Schema",
+    "description": "Defines environment variable names and values",
+    "items": {
+        "$id": "#/items",
+        "type": "object",
+        "title": "The Environment Variable Schema",
+        "description": "Defines an environment variable",
+        "required": ["name", "value"],
+        "additionalProperties": False,
+        "properties": {
+            "name": {
+                "$id": "#/items/properties/name",
+                "type": "string",
+                "title": "The Name Schema",
+                "description": "The name of this environment variable",
+                "default": "ENV_VAR",
+                "pattern": r"^[A-Z0-9\_]+$",
+                "examples": ["ENV_VAR"],
+            },
+            "value": {
+                "$id": "#/items/properties/value",
+                "type": "string",
+                "title": "The Value Schema",
+                "description": "The value of this environment variable",
+                "default": "env_var_value",
+                "examples": ["env_var_value"],
+            },
+        },
+    },
+}
+
+
 class Session(UUIDModel):
     """
     Tracks who has launched workstation images. The ``WorkstationImage`` will
@@ -365,6 +401,12 @@ class Region(models.TextChoices):
     history = HistoricalRecords(
         excluded_fields=["logs", "ping_times", "auth_token"]
     )
+    extra_env_vars = models.JSONField(
+        default=list,
+        blank=True,
+        help_text="Extra environment variables to include in this session",
+        validators=[JSONValidator(schema=ENV_VARS_SCHEMA)],
+    )
 
     class Meta(UUIDModel.Meta):
         ordering = ("created", "creator")
@@ -412,13 +454,16 @@ def environment(self) -> dict:
         -------
             The environment variables that should be set on the container.
         """
-        env = {
-            "NGINX_RESOLVER": settings.WORKSTATIONS_DNS_RESOLVER,
-            "GRAND_CHALLENGE_API_ROOT": unquote(reverse("api:api-root")),
-            "WORKSTATION_SENTRY_DSN": settings.WORKSTATION_SENTRY_DSN,
-            "WORKSTATION_SESSION_ID": str(self.pk),
-            "CIRRUS_KEEP_ALIVE_METHOD": "old",
-        }
+        env = {var["name"]: var["value"] for var in self.extra_env_vars}
+
+        env.update(
+            {
+                "GRAND_CHALLENGE_API_ROOT": unquote(reverse("api:api-root")),
+                "WORKSTATION_SENTRY_DSN": settings.WORKSTATION_SENTRY_DSN,
+                "WORKSTATION_SESSION_ID": str(self.pk),
+                "CIRRUS_KEEP_ALIVE_METHOD": "old",
+            }
+        )
 
         if self.creator:
             if self.auth_token:

app/grandchallenge/workstations/templates/workstations/session_debug_form.html

@@ -0,0 +1,31 @@
+{% extends "base.html" %}
+{% load crispy_forms_tags %}
+{% load static %}
+
+{% block title %}Create Debug Session - {{ block.super }}{% endblock %}
+
+{% block breadcrumbs %}
+    <ol class="breadcrumb">
+        <li class="breadcrumb-item"><a href="{% url 'workstations:list' %}">Viewers</a>
+        </li>
+        <li class="breadcrumb-item"><a
+                href="{{ object.workstation.get_absolute_url }}">{{ object.workstation.title }}</a>
+        </li>
+        <li class="breadcrumb-item"><a
+                href="{{ object.get_absolute_url }}">{{ object }}</a>
+        </li>
+        <li class="breadcrumb-item active"
+            aria-current="page">Create Debug Session
+        </li>
+    </ol>
+{% endblock %}
+
+{% block content %}
+    <h2>Create Debug Session</h2>
+
+    {% if unsupported_browser_message %}
+        <div class="alert alert-danger">{{ unsupported_browser_message }}</div>
+    {% endif %}
+
+    {% crispy form %}
+{% endblock %}

app/grandchallenge/workstations/templates/workstations/workstation_detail.html

@@ -154,5 +154,9 @@ <h3>Sessions</h3>
             <i class="fas fa-flask"></i> Start a new session
         </a>
 
+        <a class="btn btn-warning" href="{% url 'workstations:workstation-debug-session-create' slug=object.slug %}">
+            <i class="fas fa-flask"></i> Start a new debug session
+        </a>
+
     {% endif %}
 {% endblock %}

app/grandchallenge/workstations/urls.py

@@ -1,6 +1,7 @@
 from django.urls import path
 
 from grandchallenge.workstations.views import (
+    DebugSessionCreate,
     SessionCreate,
     WorkstationCreate,
     WorkstationDetail,
@@ -18,7 +19,6 @@
 urlpatterns = [
     path("", WorkstationList.as_view(), name="list"),
     path("create/", WorkstationCreate.as_view(), name="create"),
-    # TODO - add region
     path(
         "sessions/create/",
         SessionCreate.as_view(),
@@ -29,6 +29,11 @@
         SessionCreate.as_view(),
         name="workstation-session-create",
     ),
+    path(
+        "<slug>/sessions/debug/create/",
+        DebugSessionCreate.as_view(),
+        name="workstation-debug-session-create",
+    ),
     path(
         "<slug>/editors/update/",
         WorkstationEditorsUpdate.as_view(),

app/grandchallenge/workstations/utils.py

@@ -6,7 +6,8 @@ def get_or_create_active_session(
     user,
     workstation_image: WorkstationImage,
     region: str,
-    ping_times: str = None,
+    ping_times=None,
+    extra_env_vars=None,
 ) -> Session:
     """
     Queries the database to see if there is an active session for this user and
@@ -40,7 +41,9 @@ def get_or_create_active_session(
             creator=user,
             workstation_image=workstation_image,
             region=region,
-            ping_times=ping_times,
+            # Ping times and env vars are only set for new Sessions
+            ping_times=ping_times or None,
+            extra_env_vars=extra_env_vars or [],
         )
 
     return session