Use setuptools entry points instead of DeferredImport

This way, it is possible to use services implemented in external
packages

Signed-off-by: Patrick Uiterwijk <puiterwijk@redhat.com>

bugwarrior/command.py

@@ -12,7 +12,7 @@
 from taskw.warrior import TaskWarriorBase
 
 from bugwarrior.config import get_taskrc_path, load_config
-from bugwarrior.services import aggregate_issues, SERVICES
+from bugwarrior.services import aggregate_issues, get_service
 from bugwarrior.db import (
     get_defined_udas_as_strings,
     synchronize,
@@ -91,7 +91,7 @@ def targets():
            section.startswith('flavor.'):
             continue
         service_name = config.get(section, 'service')
-        service_class = SERVICES[service_name]
+        service_class = get_service(service_name)
         for option in config.options(section):
             value = config.get(section, option)
             if not value:

bugwarrior/config.py

@@ -126,11 +126,11 @@ def validate_config(config, main_section):
         if not service:
             die("No 'service' in [%s]" % target)
 
-        if service not in SERVICES:
+        if not get_service(service):
             die("'%s' in [%s] is not a valid service." % (service, target))
 
         # Call the service-specific validator
-        SERVICES[service].validate_config(config, target)
+        get_service(service).validate_config(config, target)
 
 
 def load_config(main_section):
@@ -168,4 +168,4 @@ def get_taskrc_path(conf, main_section):
 
 
 # This needs to be imported here and not above to avoid a circular-import.
-from bugwarrior.services import SERVICES
+from bugwarrior.services import get_service

bugwarrior/db.py

@@ -461,11 +461,11 @@ def _bool_option(section, option, default):
 
 
 def build_key_list(targets):
-    from bugwarrior.services import SERVICES
+    from bugwarrior.services import get_service
 
     keys = {}
     for target in targets:
-        keys[target] = SERVICES[target].ISSUE_CLASS.UNIQUE_KEY
+        keys[target] = get_service(target).ISSUE_CLASS.UNIQUE_KEY
     return keys
 
 
@@ -509,11 +509,11 @@ def build_uda_config_overrides(targets):
 
     """
 
-    from bugwarrior.services import SERVICES
+    from bugwarrior.services import get_service
 
     targets_udas = {}
     for target in targets:
-        targets_udas.update(SERVICES[target].ISSUE_CLASS.UDAS)
+        targets_udas.update(get_service(target).ISSUE_CLASS.UDAS)
     return {
         'uda': targets_udas
     }

bugwarrior/services/__init__.py

@@ -2,6 +2,8 @@
 import multiprocessing
 import time
 
+from pkg_resources import iter_entry_points
+
 from dateutil.parser import parse as parse_date
 from dateutil.tz import tzlocal
 from jinja2 import Template
@@ -11,7 +13,6 @@
 
 from taskw.task import Task
 
-from bugwarrior.utils import DeferredImportingDict
 from bugwarrior.config import asbool
 from bugwarrior.db import MARKUP, URLShortener, ABORT_PROCESSING
 
@@ -24,26 +25,14 @@
 # date string to be parsed as if it were in your local timezone
 LOCAL_TIMEZONE = 'LOCAL_TIMEZONE'
 
-# Constant dict to be used all around town.
-# It will defer actually importing a service until someone tries to access it
-# in the dict.  This should help expose odd ImportErrors in a more obvious way
-# for end users.  See https://github.com/ralphbean/bugwarrior/issues/132
-SERVICES = DeferredImportingDict({
-    'github':        'bugwarrior.services.github:GithubService',
-    'gitlab':        'bugwarrior.services.gitlab:GitlabService',
-    'bitbucket':     'bugwarrior.services.bitbucket:BitbucketService',
-    'trac':          'bugwarrior.services.trac:TracService',
-    'bugzilla':      'bugwarrior.services.bz:BugzillaService',
-    'teamlab':       'bugwarrior.services.teamlab:TeamLabService',
-    'redmine':       'bugwarrior.services.redmine:RedMineService',
-    'activecollab2': 'bugwarrior.services.activecollab2:ActiveCollab2Service',
-    'activecollab':  'bugwarrior.services.activecollab:ActiveCollabService',
-    'jira':          'bugwarrior.services.jira:JiraService',
-    'megaplan':      'bugwarrior.services.megaplan:MegaplanService',
-    'phabricator':   'bugwarrior.services.phab:PhabricatorService',
-    'versionone':    'bugwarrior.services.versionone:VersionOneService',
-    'pagure':        'bugwarrior.services.pagure:PagureService',
-})
+def get_service(service_name):
+    epoint = iter_entry_points(group='bugwarrior.service', name=service_name)
+    try:
+        epoint = epoint.next()
+    except StopIteration:
+        return None
+
+    return epoint.load()
 
 
 class IssueService(object):
@@ -496,7 +485,7 @@ def _aggregate_issues(conf, main_section, target, queue, service_name):
     start = time.time()
 
     try:
-        service = SERVICES[service_name](conf, main_section, target)
+        service = get_service(service_name)(conf, main_section, target)
         issue_count = 0
         for issue in service.issues():
             queue.put(issue)

setup.py

@@ -58,5 +58,20 @@
       bugwarrior-pull = bugwarrior:pull
       bugwarrior-vault = bugwarrior:vault
       bugwarrior-uda = bugwarrior:uda
+      [bugwarrior.service]
+      github=bugwarrior.services.github:GithubService
+      gitlab=bugwarrior.services.gitlab:GitlabService
+      bitbucket=bugwarrior.services.bitbucket:BitbucketService
+      trac=bugwarrior.services.trac:TracService
+      bugzilla=bugwarrior.services.bz:BugzillaService
+      teamlab=bugwarrior.services.teamlab:TeamLabService
+      redmine=bugwarrior.services.redmine:RedMineService
+      activecollab2=bugwarrior.services.activecollab2:ActiveCollab2Service
+      activecollab=bugwarrior.services.activecollab:ActiveCollabService
+      jira=bugwarrior.services.jira:JiraService
+      megaplan=bugwarrior.services.megaplan:MegaplanService
+      phabricator=bugwarrior.services.phab:PhabricatorService
+      versionone=bugwarrior.services.versionone:VersionOneService
+      pagure=bugwarrior.services.pagure:PagureService
       """,
       )