Hub, plugins and tools inputs validation

Fixes: https://pagure.io/koji/issue/3319

tests/test_hub/test_build_image_indirection.py

@@ -0,0 +1,33 @@
+import unittest
+import koji
+import kojihub
+import mock
+
+
+class TestBuildImageIndirection(unittest.TestCase):
+
+    def setUp(self):
+        self.context = mock.patch('kojihub.context').start()
+        self.exports = kojihub.RootExports()
+        self.context.session.assertPerm = mock.MagicMock()
+        self.context.session.hasPerm = mock.MagicMock()
+
+    def tearDown(self):
+        mock.patch.stopall()
+
+    def test_priority_without_admin(self):
+        priority = -10
+        self.context.session.assertPerm.side_effect = None
+        self.context.session.hasPerm.return_value = False
+        with self.assertRaises(koji.ActionNotAllowed) as cm:
+            self.exports.buildImageIndirection(priority=priority)
+        self.assertEqual("only admins may create high-priority tasks", str(cm.exception))
+
+    def test_opts_without_expected_keys(self):
+        priority = 10
+        opts = {}
+        self.context.session.assertPerm.side_effect = None
+        with self.assertRaises(koji.ActionNotAllowed) as cm:
+            self.exports.buildImageIndirection(opts=opts, priority=priority)
+        self.assertEqual("Non-scratch builds must provide url for the indirection template",
+                         str(cm.exception))