apps and categories in apps page are not displayed if oc_data/appdata_XXXXXX isn't writeable by webserver

[adsworth]

Steps to reproduce

1. make sure /appdata_XXXXX is not writeable by the webserver
2. load the apps page in nextcloud

Expected behaviour

An error message should be displayed

Actual behaviour

no categories other than enabled and not enabled are displayed and no apps are displayed.
The logs contain the following errors:

{"reqId":"8EYr7hKkWOI/kW8RLPDP","remoteAddr":"87.154.113.179","app":"index","message":"Exception: {"Exception":"OCP\\Files\\NotFoundException","Message":"\/appdata_oc80d864d4c2\/appstore","Code":0,"Trace":"#0 \/home\/oc\/doc_root\/lib\/private\/Files\/Node\/Folder.php(122): OC\\Files\\Node\\Root->get('\/appdata_oc80d8...')\n#1 \/home\/oc\/doc_root\/lib\/private\/Files\/AppData\/AppData.php(105): OC\\Files\\Node\\Folder->get('\/')\n#2 \/home\/oc\/doc_root\/lib\/private\/App\/AppStore\/Fetcher\/Fetcher.php(76): OC\\Files\\AppData\\AppData->getFolder('\/')\n#3 \/home\/oc\/doc_root\/lib\/private\/Installer.php(359): OC\\App\\AppStore\\Fetcher\\Fetcher->get()\n#4 \/home\/oc\/doc_root\/settings\/Controller\/AppSettingsController.php(280): OC\\Installer::isUpdateAvailable('systemtags', Object(OC\\App\\AppStore\\Fetcher\\AppFetcher))\n#5 [internal function]: OC\\Settings\\Controller\\AppSettingsController->listApps('enabled')\n#6 \/home\/oc\/doc_root\/lib\/private\/AppFramework\/Http\/Dispatcher.php(160): call_user_func_array(Array, Array)\n#7 \/home\/oc\/doc_root\/lib\/private\/AppFramework\/Http\/Dispatcher.php(90): OC\\AppFramework\\Http\\Dispatcher->executeController(Object(OC\\Settings\\Controller\\AppSettingsController), 'listApps')\n#8 \/home\/oc\/doc_root\/lib\/private\/AppFramework\/App.php(114): OC\\AppFramework\\Http\\Dispatcher->dispatch(Object(OC\\Settings\\Controller\\AppSettingsController), 'listApps')\n#9 \/home\/oc\/doc_root\/lib\/private\/AppFramework\/Routing\/RouteActionHandler.php(47): OC\\AppFramework\\App::main('OC\\\\Settings\\\\Con...', 'listApps', Object(OC\\AppFramework\\DependencyInjection\\DIContainer), Array)\n#10 [internal function]: OC\\AppFramework\\Routing\\RouteActionHandler->__invoke(Array)\n#11 \/home\/oc\/doc_root\/lib\/private\/Route\/Router.php(299): call_user_func(Object(OC\\AppFramework\\Routing\\RouteActionHandler), Array)\n#12 \/home\/oc\/doc_root\/lib\/base.php(1010): OC\\Route\\Router->match('\/settings\/apps\/...')\n#13 \/home\/oc\/doc_root\/index.php(40): OC::handleRequest()\n#14 {main}","File":"\/home\/oc\/doc_root\/lib\/private\/Files\/Node\/Root.php","Line":200}","level":3,"time":"2016-12-15T20:00:58+00:00","method":"GET","url":"/index.php/settings/apps/list?category=enabled","user":"oc_admin","version":"11.0.0.10"}
{"reqId":"vb1C34EtChL0z6bpXDAP","remoteAddr":"87.154.113.179","app":"index","message":"Exception: {"Exception":"OCP\\Files\\NotFoundException","Message":"\/appdata_oc80d864d4c2\/appstore","Code":0,"Trace":"#0 \/home\/oc\/doc_root\/lib\/private\/Files\/Node\/Folder.php(122): OC\\Files\\Node\\Root->get('\/appdata_oc80d8...')\n#1 \/home\/oc\/doc_root\/lib\/private\/Files\/AppData\/AppData.php(105): OC\\Files\\Node\\Folder->get('\/')\n#2 \/home\/oc\/doc_root\/lib\/private\/App\/AppStore\/Fetcher\/Fetcher.php(76): OC\\Files\\AppData\\AppData->getFolder('\/')\n#3 \/home\/oc\/doc_root\/settings\/Controller\/AppSettingsController.php(134): OC\\App\\AppStore\\Fetcher\\Fetcher->get()\n#4 [internal function]: OC\\Settings\\Controller\\AppSettingsController->listCategories()\n#5 \/home\/oc\/doc_root\/lib\/private\/AppFramework\/Http\/Dispatcher.php(160): call_user_func_array(Array, Array)\n#6 \/home\/oc\/doc_root\/lib\/private\/AppFramework\/Http\/Dispatcher.php(90): OC\\AppFramework\\Http\\Dispatcher->executeController(Object(OC\\Settings\\Controller\\AppSettingsController), 'listCategories')\n#7 \/home\/oc\/doc_root\/lib\/private\/AppFramework\/App.php(114): OC\\AppFramework\\Http\\Dispatcher->dispatch(Object(OC\\Settings\\Controller\\AppSettingsController), 'listCategories')\n#8 \/home\/oc\/doc_root\/lib\/private\/AppFramework\/Routing\/RouteActionHandler.php(47): OC\\AppFramework\\App::main('OC\\\\Settings\\\\Con...', 'listCategories', Object(OC\\AppFramework\\DependencyInjection\\DIContainer), Array)\n#9 [internal function]: OC\\AppFramework\\Routing\\RouteActionHandler->__invoke(Array)\n#10 \/home\/oc\/doc_root\/lib\/private\/Route\/Router.php(299): call_user_func(Object(OC\\AppFramework\\Routing\\RouteActionHandler), Array)\n#11 \/home\/oc\/doc_root\/lib\/base.php(1010): OC\\Route\\Router->match('\/settings\/apps\/...')\n#12 \/home\/oc\/doc_root\/index.php(40): OC::handleRequest()\n#13 {main}","File":"\/home\/oc\/doc_root\/lib\/private\/Files\/Node\/Root.php","Line":200}","level":3,"time":"2016-12-15T20:00:58+00:00","method":"GET","url":"/index.php/settings/apps/categories","user":"oc_admin","version":"11.0.0.10"}

[rullzer]

Well yes. But why would you make it not writable. There is where we store data. If you make data/<username> not writable then <username> also can't upload data.

[adsworth]

I know my config was broken, as I executed ooc upgrade with the wrong user.
My point is that the error is not handled by Nextcloud. I just get an empty screen, there is not indication for the user that something went wrong.

[LukasReschke]

occ should ideally refuse being executed as the wrong user - actually, it checks the config.php owner already.

So I suppose your config.php is owned by root and the data folder by the web server user?

[adsworth]

not quite, it's owned by the user oc and group www-data with group writable permission and I executed it as the user oc.
But since I now really read the manual upgrade docs and found out about "sudo -u www-data", I'll go ahead and change the ownership of everything to www-data.

I still think the exceptions should be handled gracefully, instead of being ignored. :)