Allow two modules with same NSVCA but different snippet content.

closes pulp#3241

It no longer holds true to rely on NSVCA module's uniqueness, add the
hash of the document snippet to it.

CHANGES/3241.bugfix

@@ -0,0 +1 @@
+Adjust modules uniqueness to allow two modules with same NSVCA but different snippet content.

pulp_rpm/app/migrations/0052_modulemd_digest.py

@@ -0,0 +1,51 @@
+# Generated by Django 4.2.4 on 2023-09-04 14:06
+
+from django.db import migrations, models
+import hashlib
+
+
+def add_snippet_hash(apps, schema_editor):
+    """Calculate and add digest hash of the snippet."""
+
+    Modulemd = apps.get_model("rpm", "Modulemd")
+    modules_to_update = []
+
+    for mmd in Modulemd.objects.all().only("snippet").iterator():
+        digest = hashlib.sha256(mmd.snippet.encode()).hexdigest()
+        modules_to_update.append(mmd)
+    Modulemd.objects.bulk_update(modules_to_update, fields=["digest"])
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("rpm", "0051_alter_distributiontree_unique_together_and_more"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="modulemd",
+            name="digest",
+            field=models.TextField(default=""),
+        ),
+        migrations.RunPython(
+            code=add_snippet_hash,
+            reverse_code=migrations.RunPython.noop,
+            elidable=True,
+        ),
+        migrations.AlterUniqueTogether(
+            name="modulemd",
+            unique_together=set(),
+        ),
+        migrations.AlterField(
+            model_name="modulemd",
+            name="digest",
+            field=models.TextField(),
+        ),
+        migrations.AlterUniqueTogether(
+            name="modulemd",
+            unique_together={
+                ("_pulp_domain", "name", "stream", "version", "context", "arch", "digest")
+            },
+        ),
+    ]

pulp_rpm/app/models/modulemd.py

@@ -45,7 +45,10 @@ class Modulemd(Content):
         packages (Text):
             List of Packages connected to this modulemd.
         snippet (Text):
-            A string to hold modulemd-obsolete snippet
+            A string to hold modulemd snippet
+        digest (Text):
+            Modulemd snippet digest
+
     """
 
     TYPE = "modulemd"
@@ -63,14 +66,16 @@ class Modulemd(Content):
     packages = models.ManyToManyField(Package)
     profiles = models.JSONField(default=dict)
     description = models.TextField()
+    digest = models.TextField()
 
     snippet = models.TextField()
+    repo_key_fields = ("name", "stream", "version", "context", "arch")
 
     _pulp_domain = models.ForeignKey("core.Domain", default=get_domain_pk, on_delete=models.PROTECT)
 
     class Meta:
         default_related_name = "%(app_label)s_%(model_name)s"
-        unique_together = ("_pulp_domain", "name", "stream", "version", "context", "arch")
+        unique_together = ("_pulp_domain", "name", "stream", "version", "context", "arch", "digest")
 
 
 class ModulemdDefaults(Content):
@@ -85,9 +90,9 @@ class ModulemdDefaults(Content):
         profiles (Json):
             Default profiles for modulemd streams.
         digest (Text):
-            Modulemd digest
+            Modulemd defaults snippet digest
         snippet (Text):
-            A string to hold modulemd-obsolete snippet
+            A string to hold modulemd-defaults snippet
     """
 
     TYPE = "modulemd_defaults"

pulp_rpm/app/modulemd.py

@@ -129,6 +129,7 @@ def create_modulemd(modulemd, snippet):
 
     new_module[PULP_MODULE_ATTR.PROFILES] = profiles
     new_module["snippet"] = snippet
+    new_module[PULP_MODULE_ATTR.DIGEST] = hashlib.sha256(snippet.encode()).hexdigest()
 
     return new_module