Automatic update checks (#434)

* Basic update checks

* Fix issues pointed out by @rixx

* First test

* Add tests

* Even more tests

src/pretix/base/__init__.py

@@ -9,7 +9,7 @@ class PretixBaseConfig(AppConfig):
         from . import exporter  # NOQA
         from . import payment  # NOQA
         from . import exporters  # NOQA
-        from .services import export, mail, tickets, cart, orders, cleanup  # NOQA
+        from .services import export, mail, tickets, cart, orders, cleanup, update_check  # NOQA
 
         try:
             from .celery_app import app as celery_app  # NOQA

src/pretix/base/management/commands/rebuild.py

@@ -1,6 +1,8 @@
 from django.core.management import call_command
 from django.core.management.base import BaseCommand
 
+from pretix.base.settings import GlobalSettingsObject
+
 
 class Command(BaseCommand):
     help = "Rebuild static files and language files"
@@ -10,3 +12,7 @@ class Command(BaseCommand):
         call_command('compilejsi18n', verbosity=1, interactive=False)
         call_command('collectstatic', verbosity=1, interactive=False)
         call_command('compress', verbosity=1, interactive=False)
+        gs = GlobalSettingsObject()
+        del gs.settings.update_check_last
+        del gs.settings.update_check_result
+        del gs.settings.update_check_result_warning

src/pretix/base/services/update_check.py

@@ -0,0 +1,125 @@
+import sys
+import uuid
+from datetime import timedelta
+
+import requests
+from django.dispatch import receiver
+from django.utils.timezone import now
+from django.utils.translation import ugettext_lazy as _, ugettext_noop
+from i18nfield.strings import LazyI18nString
+
+from pretix import __version__
+from pretix.base.models import Event
+from pretix.base.plugins import get_all_plugins
+from pretix.base.services.mail import mail
+from pretix.base.settings import GlobalSettingsObject
+from pretix.base.signals import periodic_task
+from pretix.celery_app import app
+from pretix.helpers.urls import build_absolute_uri
+
+
+@receiver(signal=periodic_task)
+def run_update_check(sender, **kwargs):
+    gs = GlobalSettingsObject()
+    if not gs.settings.update_check_perform:
+        return
+
+    if not gs.settings.update_check_last or now() - gs.settings.update_check_last > timedelta(hours=23):
+        update_check.apply_async()
+
+
+@app.task
+def update_check():
+    gs = GlobalSettingsObject()
+    if not gs.settings.update_check_perform:
+        return
+
+    if not gs.settings.update_check_id:
+        gs.settings.set('update_check_id', uuid.uuid4().hex)
+
+    if 'runserver' in sys.argv:
+        gs.settings.set('update_check_last', now())
+        gs.settings.set('update_check_result', {
+            'error': 'development'
+        })
+        return
+
+    check_payload = {
+        'id': gs.settings.get('update_check_id'),
+        'version': __version__,
+        'events': {
+            'total': Event.objects.count(),
+            'live': Event.objects.filter(live=True).count(),
+        },
+        'plugins': [
+            {
+                'name': p.module,
+                'version': p.version
+            } for p in get_all_plugins()
+        ]
+    }
+    try:
+        r = requests.post('https://pretix.eu/.update_check/', json=check_payload)
+        gs.settings.set('update_check_last', now())
+        if r.status_code != 200:
+            gs.settings.set('update_check_result', {
+                'error': 'http_error'
+            })
+        else:
+            rdata = r.json()
+            update_available = rdata['version']['updatable'] or any(p['updatable'] for p in rdata['plugins'].values())
+            gs.settings.set('update_check_result_warning', update_available)
+            if update_available and rdata != gs.settings.update_check_result:
+                send_update_notification_email()
+            gs.settings.set('update_check_result', rdata)
+    except requests.RequestException:
+        gs.settings.set('update_check_last', now())
+        gs.settings.set('update_check_result', {
+            'error': 'unavailable'
+        })
+
+
+def send_update_notification_email():
+    gs = GlobalSettingsObject()
+    if not gs.settings.update_check_email:
+        return
+
+    mail(
+        gs.settings.update_check_email,
+        _('pretix update available'),
+        LazyI18nString.from_gettext(
+            ugettext_noop(
+                'Hi!\n\nAn update is available for pretix or for one of the plugins you installed in your '
+                'pretix installation. Please click on the following link for more information:\n\n {url} \n\n'
+                'You can always find information on the latest updates on the pretix.eu blog:\n\n'
+                'https://pretix.eu/about/en/blog/'
+                '\n\nBest,\n\nyour pretix developers'
+            )
+        ),
+        {
+            'url': build_absolute_uri('control:global.update')
+        },
+    )
+
+
+def check_result_table():
+    gs = GlobalSettingsObject()
+    res = gs.settings.update_check_result
+    if not res:
+        return {
+            'error': 'no_result'
+        }
+
+    if 'error' in res:
+        return res
+
+    table = []
+    table.append(('pretix', __version__, res['version']['latest'], res['version']['updatable']))
+    for p in get_all_plugins():
+        if p.module in res['plugins']:
+            pdata = res['plugins'][p.module]
+            table.append((_('Plugin: %s') % p.name, p.version, pdata['latest'], pdata['updatable']))
+        else:
+            table.append((_('Plugin: %s') % p.name, p.version, '?', False))
+
+    return table

src/pretix/base/settings.py

@@ -351,6 +351,34 @@ Your {event} team"""))
     'frontpage_text': {
         'default': '',
         'type': LazyI18nString
+    },
+    'update_check_ack': {
+        'default': 'False',
+        'type': bool
+    },
+    'update_check_email': {
+        'default': '',
+        'type': str
+    },
+    'update_check_perform': {
+        'default': 'True',
+        'type': bool
+    },
+    'update_check_result': {
+        'default': None,
+        'type': dict
+    },
+    'update_check_result_warning': {
+        'default': 'False',
+        'type': bool
+    },
+    'update_check_last': {
+        'default': None,
+        'type': datetime
+    },
+    'update_check_id': {
+        'default': None,
+        'type': str
     }
 }