Ensure that we limit the length of repository names

Until now, they'd simply be truncated by the database. Now, we properly check their lengths.

Fixes https://jira.coreos.com/browse/QUAY-963

endpoints/api/test/test_repository.py

@@ -96,3 +96,24 @@ def test_list_starred_repos(client):
     repos = {r['namespace'] + '/' + r['name'] for r in response['repositories']}
     assert 'devtable/simple' in repos
     assert 'public/publicrepo' not in repos
+
+
+@pytest.mark.parametrize('repo_name, expected_status', [
+  pytest.param('x' * 255, 201, id='Maximum allowed length'),
+  pytest.param('x' * 256, 400, id='Over allowed length'),
+  pytest.param('a|b', 400, id='Invalid name'),
+])
+def test_create_repository(repo_name, expected_status, client):
+  with client_with_identity('devtable', client) as cl:
+    body = {
+      'namespace': 'devtable',
+      'repository': repo_name,
+      'visibility': 'public',
+      'description': 'foo',
+    }
+
+    result = conduct_api_call(client, RepositoryList, 'post', None, body,
+                              expected_code=expected_status).json
+    if expected_status == 201:
+      assert result['name'] == repo_name
+      assert model.repository.get_repository('devtable', repo_name).name == repo_name