Monday, December 29, 2014

Welcome to new team member Mahmoud from Egypt

I think it is time to present our new team member Mahmoud who agreed to assist me at least for a few months. And of course we hope that this is just the beginning of a long releationship. Mahmoud is my “assistant”. He will help me to develop and maintain Lino. In a first phase he must still learn. While teaching him, I will build reusable documentation for future team members. The long-term goal is that he works independently on tasks which we assign to him after consultation.

Merged lino.ui into lino.core

I merged the content of the lino.ui package into lino.core, because this differentiation was historical and irritating.

  • File renames:

    mv ui/elems.py core/
mv ui/store.py core/
mv ui/urls.py core/
mv ui/render.py core/renderer.py
rm ui/ui.py
rm ui/base.py

  • Moved class lino.ui.base.Handle to lino.core.utils.Handle.

Calendar

There was a problem for generating the calendar view of a blogger_year: the cell for today (December 29, 2014) was not clickable although a blog entry existed. I think it is because today we are already in week 1 of 2015. It is possible that we will know more in three days…

Released atelier version 0.0.10, mainly for Mahmoud.

AttributeError ‘module’ object has no attribute ‘ContentType’

File lino/modlib/courses/models.py in events_by_course, line 444

This was a simple typo bug which occurred in Renamed “Lino Faggio” to “Lino Voga”. Fixed.

TODO: write test case which would have detected it.

‘NoneType’ object has no attribute ‘get_view_permission’

The above error message came when editing or displaying objects in a table without detail_layout. Fixed.

Optimization en passant: The <head> block of Lino’s html contained many empty lines, which made it difficult to read for humans. Fixed.

Problems with mod_wsgi in daemon mode

Wow. I had a few hours of stress after an upgrade of the production server in CPAS de Châtelet.

  • TypeError: H is undefined in the JavaScript console in CPAS de Châtelet after upgrading. And this caused the detail window for clients to not open but to produce another Javascript error TypeError: Lino.pcsw.Clients.detail is undefined.

  • AssertionError at / and No exception message supplied, and the system.log showing:

    File "/usr/local/repositories/lino/lino/modlib/extjs/ext_renderer.py", line 748, in write_lino_js
    assert profile == jsgen._for_user_profile
AssertionError

    or:

    Exception: <ParamsPanel main in ParamsLayout on newcomers.AvailableCoaches> of LayoutHandle for ParamsLayout on newcomers.AvailableCoaches has no variables

All these diverse phenomens had a single cause: a wrong configuration of mod_wsgi.

Some print statements in the wsgi.py file were useful for diagnosing the problem:

print sys.path
import mod_wsgi
print mod_wsgi.version
from lino import hello

The mod_wsgi.version on this server is (3, 3).

To see this more easily in the future, I added mod_wsgi to the items reported by get_used_libs.

The output of aptitude confirmed the mod_wsgi version:

$ aptitude show libapache2-mod-wsgi
Package: libapache2-mod-wsgi
State: installed
Automatically installed: no
Version: 3.3-4+deb7u1
Priority: optional
...

The guilty was that the different threads got activated using different version of Python, Django and Lino.

The Django docs say:

“Daemon mode” is the recommended mode for running mod_wsgi (…) in daemon mode you can’t use WSGIPythonPath; instead you should use the python-path option to WSGIDaemonProcess.

This led me to try this option to WSGIDaemonProcess:

WSGIDaemonProcess lino_prod threads=15 python-path=/var/www/vhosts/prod/env/local/lib/python2.7/site-packages

And it solved all problems.

Until today the following trick in the djangosite_local.py had worked well:

site.addsitedir(join(home_dir, "env/local/lib/python2.7/site-packages"))

I ignore the details, but I guess that it stopped to work after some update.

Note that I still recommend to create your virtualenvs in an independent system-wide place (e.g. /usr/local/virtualenvs) and then, in your project directories, make a symbolic link called “env” which points to one of these virtualenvs.