Add model and dispatch a basic task for the migration tool

closes #5003
https://pulp.plan.io/issues/5003

README.md

@@ -37,11 +37,8 @@ $ sudo mount <IP address of machine which exports /var/lib/pulp>:/var/lib/pulp /
 
 ### Installation
 
-Clone repositories for the base tool and extensions for the plugins of interest, and install them.
+Clone the repository and install it.
 ```
 $ git clone https://github.com/pulp/pulp-2to3-migrate.git
 $ pip install -e pulp-2to3-migrate
-$
-$ git clone https://github.com/pulp/pulp-2to3-migrate-iso.git
-$ pip install -e pulp-2to3-migrate-iso
-```
+```

pulp_2to3_migrate/app/constants.py

@@ -0,0 +1,2 @@
+# for tasking system to ensure only one migration is run at a time
+PULP_2TO3_MIGRATION_RESOURCE = "pulp_2to3_migration"

pulp_2to3_migrate/app/models.py

@@ -1,6 +1,7 @@
 from django.db import models
 
-class Pulp2To3Map(models.Model):
-    pulp2_id = models.UUIDField(primary_key=True)
-    pulp3_id = models.UUIDField()
-    type = models.CharField(max_length=255)
+from pulpcore.plugin.models import Model
+
+
+class MigrationPlan(Model):
+    plan = models.TextField()

pulp_2to3_migrate/app/serializers.py

@@ -0,0 +1,50 @@
+from gettext import gettext as _
+
+from rest_framework import serializers
+
+from pulpcore.plugin.serializers import (
+    ModelSerializer,
+    IdentityField
+)
+
+from .models import MigrationPlan
+
+class MigrationPlanSerializer(ModelSerializer):
+    _href = IdentityField(
+        view_name='migration-plans-detail'
+    )
+
+    plan = serializers.CharField(
+        help_text= _('Migration Plan in JSON format'),
+        required=True,
+    )
+
+    class Meta:
+        fields = ModelSerializer.Meta.fields + ('plan', )
+        model = MigrationPlan
+
+
+    def validate(self, data):
+        """
+        Validate that the Serializer contains valid data.
+
+        TODO:
+        Validate JSON structure of migration_plan.
+        Check validity of the JSON content:
+         - migration for requested plugins is supported
+
+        """
+        return data
+
+
+class MigrationPlanRunSerializer(serializers.Serializer):
+    """
+    A serializer for running a migration plan.
+    """
+    dry_run = serializers.BooleanField(
+        help_text=_('If ``True``, performs validation of a Migration Plan only, no migration is '
+                    'run. If ``False``, both validation and migration are run.'),
+        required=False,
+        default=False,
+        write_only=True
+    )

pulp_2to3_migrate/app/tasks/migrate.py

@@ -0,0 +1,13 @@
+import time
+
+def migrate_from_pulp2(migration_plan_pk, dry_run=False):
+    """
+    Main task to migrate from Pulp 2 to Pulp 3.
+
+    Schedule other tasks based on the specified Migration Plan.
+
+    Args:
+        migration_plan_pk (str): The migration plan PK.
+        dry_run (bool): If True, nothing is migrated, only validation happens.
+    """
+    time.sleep(1)

pulp_2to3_migrate/app/viewsets.py

@@ -0,0 +1,52 @@
+from drf_yasg.utils import swagger_auto_schema
+from rest_framework import mixins
+from rest_framework.decorators import detail_route
+
+from pulpcore.plugin.serializers import AsyncOperationResponseSerializer
+from pulpcore.plugin.tasking import enqueue_with_reservation
+from pulpcore.plugin.viewsets import (
+    NamedModelViewSet,
+    OperationPostponedResponse,
+)
+
+from .constants import PULP_2TO3_MIGRATION_RESOURCE
+from .models import MigrationPlan
+from .serializers import (
+    MigrationPlanSerializer,
+    MigrationPlanRunSerializer,
+)
+from .tasks.migrate import migrate_from_pulp2
+
+
+class MigrationPlanViewSet(NamedModelViewSet,
+                           mixins.CreateModelMixin,
+                           mixins.RetrieveModelMixin,
+                           mixins.DestroyModelMixin,
+                           mixins.ListModelMixin):
+    endpoint_name = 'migration-plans'
+    queryset = MigrationPlan.objects.all()
+    serializer_class = MigrationPlanSerializer
+
+    @swagger_auto_schema(
+        operation_summary="Run migration plan",
+        operation_description="Trigger an asynchronous task to run a migration from Pulp 2.",
+        responses={202: AsyncOperationResponseSerializer}
+    )
+    @detail_route(methods=('post',), serializer_class=MigrationPlanRunSerializer)
+    def run(self, request, pk):
+        migration_plan = self.get_object()
+        serializer = MigrationPlanRunSerializer(
+            data=request.data,
+            context={'request': request}
+        )
+        serializer.is_valid(raise_exception=True)
+        dry_run = serializer.validated_data.get('dry_run', False)
+        result = enqueue_with_reservation(
+            migrate_from_pulp2,
+            [PULP_2TO3_MIGRATION_RESOURCE],
+            kwargs={
+                'migration_plan_pk': migration_plan.pk,
+                'dry_run': dry_run
+            }
+        )
+        return OperationPostponedResponse(result, request)

setup.py

@@ -9,7 +9,7 @@
 
 setup(
     name='pulp-2to3-migrate',
-    version='0.0.1a1.dev1',
+    version='0.0.1a1.dev',
     description='Pulp 2 to Pulp 3 migration tool',
     license='GPLv2+',
     author='Pulp Team',