Merge ~ltrager/maas:lp1916317_2.9 into maas:2.9

[Lee Trager]

LP: #1916317 - Add web socket function to delete or download Script content

Backport of 6fa37cd

[Lee Trager (ltrager)]

review: Approve

[MAAS Lander (maas-lander)]

LANDING
-b lp1916317_2.9 lp:~ltrager/maas/+git/maas into -b 2.9 lp:~maas-committers/maas

STATUS: FAILED BUILD
LOG: http://maas-ci.internal:8080/job/maas/job/branch-tester/9305/consoleText

diff --git a/src/maasserver/websockets/handlers/script.py b/src/maasserver/websockets/handlers/script.py
index 19db14c..c46a4f9 100644
--- a/src/maasserver/websockets/handlers/script.py
+++ b/src/maasserver/websockets/handlers/script.py
@@ -1,9 +1,14 @@
-# Copyright 2017-2019 Canonical Ltd.  This software is licensed under the
+# Copyright 2017-2021 Canonical Ltd.  This software is licensed under the
 # GNU Affero General Public License version 3 (see the file LICENSE).
 
 """The Script handler for the WebSocket connection."""
 
 
+from maasserver.permissions import NodePermission
+from maasserver.websockets.base import (
+    HandlerDoesNotExistError,
+    HandlerPermissionError,
+)
 from maasserver.websockets.handlers.timestampedmodel import (
     TimestampedModelHandler,
 )
@@ -14,5 +19,33 @@ class ScriptHandler(TimestampedModelHandler):
     class Meta:
         queryset = Script.objects.all()
         pk = "id"
-        allowed_methods = ["list"]
+        allowed_methods = [
+            "delete",
+            "get_script",
+            "list",
+        ]
         listen_channels = ["script"]
+
+    def delete(self, params):
+        script = self.get_object(params)
+        if not self.user.has_perm(NodePermission.admin) or script.default:
+            raise HandlerPermissionError()
+        script.delete()
+
+    def get_script(self, params):
+        id = params.get("id")
+        revision = params.get("revision")
+        script = self.get_object(params)
+        if not script:
+            raise HandlerDoesNotExistError(
+                f"Script with id({id}) does not exist!"
+            )
+        if revision:
+            for rev in script.script.previous_versions():
+                if rev.id == revision:
+                    return rev.data
+            raise HandlerDoesNotExistError(
+                f"Unable to find revision {revision} for {script.name}."
+            )
+        else:
+            return script.script.data
diff --git a/src/maasserver/websockets/handlers/tests/test_script.py b/src/maasserver/websockets/handlers/tests/test_script.py
index 8ddf5cd..5c778fe 100644
--- a/src/maasserver/websockets/handlers/tests/test_script.py
+++ b/src/maasserver/websockets/handlers/tests/test_script.py
@@ -1,12 +1,18 @@
-# Copyright 2017-2019 Canonical Ltd.  This software is licensed under the
+# Copyright 2017-2021 Canonical Ltd.  This software is licensed under the
 # GNU Affero General Public License version 3 (see the file LICENSE).
 
 """Tests for `maasserver.websockets.handlers.script`"""
 
+import random
 
 from maasserver.testing.factory import factory
 from maasserver.testing.testcase import MAASServerTestCase
-from maasserver.websockets.base import dehydrate_datetime
+from maasserver.utils.orm import reload_object
+from maasserver.websockets.base import (
+    dehydrate_datetime,
+    HandlerDoesNotExistError,
+    HandlerPermissionError,
+)
 from maasserver.websockets.handlers.script import ScriptHandler
 
 
@@ -52,3 +58,77 @@ class TestScriptHandler(MAASServerTestCase):
         sorted_results = sorted(handler.list({}), key=lambda i: i["id"])
         for expected, real in zip(expected_scripts, sorted_results):
             self.assertDictEqual(expected, real)
+
+    def test_delete(self):
+        script = factory.make_Script()
+        admin = factory.make_admin()
+        handler = ScriptHandler(admin, {}, None)
+
+        handler.delete({"id": script.id})
+
+        self.assertIsNone(reload_object(script))
+
+    def test_delete_admin_only(self):
+        script = factory.make_Script()
+        user = factory.make_User()
+        handler = ScriptHandler(user, {}, None)
+
+        self.assertRaises(
+            HandlerPermissionError, handler.delete, {"id": script.id}
+        )
+
+        self.assertIsNotNone(reload_object(script))
+
+    def test_delete_cannot_delete_default(self):
+        script = factory.make_Script(default=True)
+        admin = factory.make_admin()
+        handler = ScriptHandler(admin, {}, None)
+
+        self.assertRaises(
+            HandlerPermissionError, handler.delete, {"id": script.id}
+        )
+
+        self.assertIsNotNone(reload_object(script))
+
+    def test_get_script(self):
+        script = factory.make_Script()
+        user = factory.make_User()
+        handler = ScriptHandler(user, {}, None)
+
+        self.assertEqual(
+            script.script.data, handler.get_script({"id": script.id})
+        )
+
+    def test_get_script_not_found(self):
+        user = factory.make_User()
+        handler = ScriptHandler(user, {}, None)
+
+        self.assertRaises(
+            HandlerDoesNotExistError,
+            handler.get_script,
+            {"id": random.randint(1000, 10000)},
+        )
+
+    def test_get_script_revision(self):
+        script = factory.make_Script()
+        old_vtf = script.script
+        script.script = script.script.update(factory.make_string())
+        script.save()
+        user = factory.make_User()
+        handler = ScriptHandler(user, {}, None)
+
+        self.assertEqual(
+            old_vtf.data,
+            handler.get_script({"id": script.id, "revision": old_vtf.id}),
+        )
+
+    def test_get_script_revision_not_found(self):
+        script = factory.make_Script()
+        user = factory.make_User()
+        handler = ScriptHandler(user, {}, None)
+
+        self.assertRaises(
+            HandlerDoesNotExistError,
+            handler.get_script,
+            {"id": script.id, "revision": random.randint(1000, 10000)},
+        )