Rework how external bug tracker integrations are discovered

- All of them are now listed as dotted class paths under the
  EXTERNAL_BUG_TRACKERS setting
- DB migration will rename existing records
- tcms.issuetracker.types.from_name() is replaced with
  django.utils.module_loading.import_string() which returns the
  class at the end of a dotted path
- update documentation

Refs #1151 - will make overriding bug-tracker integration easier

Refs kiwitcms/github-app#25 - will open
the path to providing a custom GitHub Issues integration for the
GitHub App

docs/source/admin.rst

@@ -27,6 +27,15 @@ Each bug tracker is given a name, URL, API credentials and integration type.
 The extent of integration with 3rd party bug tracking systems is documented
 in :mod:`tcms.issuetracker`.
 
+.. important::
+
+    External bug tracker integration classes are defined as a dotted path list
+    in the ``EXTERNAL_BUG_TRACKERS`` setting, see :ref:`configuration`.
+    Plugins and Kiwi TCMS admins may override this setting to provide more
+    control and customized integration.
+
+    .. versionadded:: 8.5
+
 .. important::
 
     Details on what each field means can be found at

tcms/issuetracker/tests/test_bugzilla.py

@@ -31,7 +31,7 @@ def _fixture_setup(self):
 
         bug_system = BugSystem.objects.create(  # nosec:B106:hardcoded_password_funcarg
             name='Dockerized Bugzilla',
-            tracker_type='Bugzilla',
+            tracker_type='tcms.issuetracker.types.Bugzilla',
             base_url='http://bugtracker.kiwitcms.org/bugzilla/',
             api_url='http://bugtracker.kiwitcms.org/bugzilla/xmlrpc.cgi',
             api_username='[email protected]',

tcms/issuetracker/tests/test_github.py

@@ -38,7 +38,7 @@ def _fixture_setup(self):
 
         bug_system = BugSystem.objects.create(  # nosec:B106:hardcoded_password_funcarg
             name='GitHub for kiwitcms/test-github-integration',
-            tracker_type='GitHub',
+            tracker_type='tcms.issuetracker.types.GitHub',
             base_url='https://github.com/kiwitcms/test-github-integration',
             api_password=os.getenv('GH_BUGTRACKER_INTEGRATION_TEST_API_TOKEN'),
         )

tcms/issuetracker/tests/test_gitlab_ee.py

@@ -32,7 +32,7 @@ def _fixture_setup(self):
 
         bug_system = BugSystem.objects.create(  # nosec:B106:hardcoded_password_funcarg
             name='GitLab-EE for root/kiwitcms',
-            tracker_type='Gitlab',
+            tracker_type='tcms.issuetracker.types.Gitlab',
             base_url='http://bugtracker.kiwitcms.org/root/kiwitcms/',
             api_url='http://bugtracker.kiwitcms.org',
             api_password='ypCa3Dzb23o5nvsixwPA',
@@ -57,7 +57,7 @@ def test_details_for_public_url(self):
     def test_details_for_private_url(self):
         bug_system = BugSystem.objects.create(  # nosec:B106:hardcoded_password_funcarg
             name='Private GitLab for root/katinar',
-            tracker_type='Gitlab',
+            tracker_type='tcms.issuetracker.types.Gitlab',
             base_url='http://bugtracker.kiwitcms.org/root/katinar/',
             api_url='http://bugtracker.kiwitcms.org',
             api_password='ypCa3Dzb23o5nvsixwPA',

tcms/issuetracker/tests/test_jira.py

@@ -42,7 +42,7 @@ def _fixture_setup(self):
 
         bug_system = BugSystem.objects.create(  # nosec:B106:hardcoded_password_funcarg
             name='JIRA at kiwitcms.atlassian.net',
-            tracker_type='JIRA',
+            tracker_type='tcms.issuetracker.types.JIRA',
             base_url='https://kiwitcms.atlassian.net',
             api_username=os.getenv('JIRA_BUGTRACKER_INTEGRATION_API_USERNAME'),
             api_password=os.getenv('JIRA_BUGTRACKER_INTEGRATION_API_TOKEN'),

tcms/issuetracker/tests/test_kiwitcms.py

@@ -41,7 +41,7 @@ def _fixture_setup(self):
 
         bug_system = BugSystem.objects.create(  # nosec:B106:hardcoded_password_funcarg
             name='KiwiTCMS internal bug tracker',
-            tracker_type='KiwiTCMS',
+            tracker_type='tcms.issuetracker.types.KiwiTCMS',
             base_url="https://%s" % Site.objects.get(id=settings.SITE_ID).domain,
             # note: ^^^ this is https just because .get_full_url() default to that !
         )

tcms/issuetracker/tests/test_redmine.py

@@ -35,7 +35,7 @@ def _fixture_setup(self):
 
         bug_system = BugSystem.objects.create(  # nosec:B106:hardcoded_password_funcarg
             name='Redmine at kiwitcms.atlassian.net',
-            tracker_type='Redmine',
+            tracker_type='tcms.issuetracker.types.Redmine',
             base_url='http://bugtracker.kiwitcms.org:3000',
             api_username='admin',
             api_password='admin',

tcms/issuetracker/types.py

@@ -25,16 +25,6 @@
     from tcms.issuetracker.kiwitcms import KiwiTCMS  # noqa, pylint: disable=unused-import
 
 
-def from_name(name):
-    """
-        Return the class which matches ``name`` if it exists inside this
-        module or raise an exception.
-    """
-    if name not in globals():
-        raise NotImplementedError('IT of type %s is not supported' % name)
-    return globals()[name]
-
-
 class JIRA(IssueTrackerType):
     """
         Support for JIRA. Requires:

tcms/rpc/api/bug.py

@@ -1,9 +1,9 @@
 # -*- coding: utf-8 -*-
 from django.core.cache import cache
+from django.utils.module_loading import import_string
 from django.utils.translation import gettext_lazy as _
 from modernrpc.core import REQUEST_KEY, rpc_method
 
-from tcms.issuetracker.types import from_name
 from tcms.rpc.api.utils import tracker_from_url
 from tcms.testcases.models import BugSystem
 from tcms.testruns.models import TestExecution
@@ -62,7 +62,7 @@ def report(execution_id, tracker_id, **kwargs):
 
     execution = TestExecution.objects.get(pk=execution_id)
     bug_system = BugSystem.objects.get(pk=tracker_id)
-    tracker = from_name(bug_system.tracker_type)(bug_system)
+    tracker = import_string(bug_system.tracker_type)(bug_system)
     if not tracker.is_adding_testcase_to_issue_disabled():
         url = tracker.report_issue_from_testexecution(execution, request.user)
         response = {'rc': 0, 'response': url}

tcms/rpc/api/utils.py

@@ -1,8 +1,9 @@
-# Copyright (c) 2019 Alexander Todorov <[email protected]>
+# Copyright (c) 2019-2020 Alexander Todorov <[email protected]>
 
 # Licensed under the GPL 2.0: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 
-from tcms.issuetracker.types import from_name
+from django.utils.module_loading import import_string
+
 from tcms.testcases.models import BugSystem
 
 
@@ -14,6 +15,6 @@ def tracker_from_url(url):
     """
     for bug_system in BugSystem.objects.all():
         if bug_system.base_url and url.startswith(bug_system.base_url):
-            return from_name(bug_system.tracker_type)(bug_system)
+            return import_string(bug_system.tracker_type)(bug_system)
 
     return None

tcms/settings/common.py

@@ -382,6 +382,20 @@
 if 'tcms.bugs.apps.AppConfig' in INSTALLED_APPS:
     MODERNRPC_METHODS_MODULES.append('tcms.bugs.api')
 
+# This is a list of dotted class names providing integration with
+# external bug trackers. Plugins and downstream installation can augment
+# this list with their own integration classes!
+# https://kiwitcms.readthedocs.io/en/latest/admin.html#configure-external-bug-trackers
+EXTERNAL_BUG_TRACKERS = [
+    'tcms.issuetracker.types.Bugzilla',
+    'tcms.issuetracker.types.JIRA',
+    'tcms.issuetracker.types.GitHub',
+    'tcms.issuetracker.types.Gitlab',
+    'tcms.issuetracker.types.Redmine',
+]
+if 'tcms.bugs.apps.AppConfig' in INSTALLED_APPS:
+    EXTERNAL_BUG_TRACKERS.append('tcms.issuetracker.types.KiwiTCMS')
+
 # Enable the administrator delete permission
 # In another word it's set the admin to super user or not.
 SET_ADMIN_AS_SUPERUSER = False

tcms/testcases/admin.py

@@ -1,14 +1,13 @@
 # pylint: disable=no-self-use
-import inspect
 
 from django import forms
+from django.conf import settings
 from django.contrib import admin
 from django.forms.widgets import Select
 from django.http import HttpResponseRedirect
 from django.urls import reverse
 
 from tcms.core.history import ReadOnlyHistoryAdmin
-from tcms.issuetracker import types
 from tcms.testcases.models import BugSystem, Category, TestCase
 
 
@@ -50,13 +49,9 @@ def choices(self, _):
 
     @staticmethod
     def _types_as_choices():
-        trackers = []
-        for module_object in types.__dict__.values():
-            if inspect.isclass(module_object) and \
-               issubclass(module_object, types.IssueTrackerType) and \
-               module_object != types.IssueTrackerType:  # noqa: E721
-                trackers.append(module_object.__name__)
-        return (('', ''), ) + tuple(zip(trackers, trackers))
+        return (('', ''), ) + tuple(
+            zip(settings.EXTERNAL_BUG_TRACKERS,
+                settings.EXTERNAL_BUG_TRACKERS))
 
 
 class IssueTrackerTypeField(forms.ChoiceField):

tcms/testcases/migrations/0014_update_issutracker_types.py

@@ -0,0 +1,30 @@
+from django.db import migrations
+
+
+def forwards(apps, schema_editor):
+    BugSystem = apps.get_model('testcases', 'BugSystem')
+
+    for record in BugSystem.objects.all():
+        if record.tracker_type:
+            record.tracker_type = "tcms.issuetracker.types.%s" % record.tracker_type
+            record.save()
+
+
+def backwards(apps, schema_editor):
+    BugSystem = apps.get_model('testcases', 'BugSystem')
+
+    for record in BugSystem.objects.all():
+        if record.tracker_type.startswith('tcms.issuetracker.types.'):
+            record.tracker_type = record.tracker_type.replace('tcms.issuetracker.types.', '')
+            record.save()
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('testcases', '0013_remove_autofield'),
+    ]
+
+    operations = [
+        migrations.RunPython(forwards, backwards),
+    ]