edc-sites 0.1.20

Simple classes related to the django sites framework for clinicedc projects.

edc-sites

Site definitions to work with Django’s Sites Framework.

Define a sites.py. This is usually in a separate project module. For example, for project meta there is a module meta_sites that contains a sites.py.

# sites.py

fqdn = "meta.clinicedc.org"

meta_sites = (
    (10, "hindu_mandal", "Hindu Mandal Hospital"),
    (20, "amana", "Amana Hospital"),
)

Register a post_migrate signal in apps.py to update the django model Site and the EDC model SiteProfile on the next migration:

# apps.py

from .sites import meta_sites, fqdn

def post_migrate_update_sites(sender=None, **kwargs):
    from edc_sites.add_or_update_django_sites import add_or_update_django_sites

    sys.stdout.write(style.MIGRATE_HEADING("Updating sites:\n"))
    add_or_update_django_sites(
        apps=django_apps, sites=meta_sites, fqdn=fqdn, verbose=True
    )
    sys.stdout.write("Done.\n")
    sys.stdout.flush()

For another deployment, we have alot of sites spread out over a few countries. In this case we pass a dictionary and separate the lists of sites by country.

For example:

fqdn = "inte.clinicedc.org"

all_sites = {
    "tanzania":(
        (10, "hindu_mandal", "Hindu Mandal Hospital"),
        (20, "amana", "Amana Hospital"),
    ),
    "uganda":(
        (10, "kojja", "Kojja Clinic"),
        (20, "mbarara", "Mbarara Clinic"),
        (30, "kampala", "Kampala Clinic"),
    ),
}

In a mult-isite, multi-country deployment, managing the SITE_ID is complicated.

One approach is to manipulate the DJANGO_SETTINGS_MODULE.

The DJANGO_SETTINGS_MODULE is referred to by wsgi.py and can just as easily be referred to in settings itself. For example, instead of explicitly setting the SITE_ID you can use edc_sites utility get_site_from_environment.

What we would like to be able do is this:

# defaults as a test environment or whatever manage.py points to.
$ python manage.py runserver
>>> from django.conf import settings
>>> setting.SITE_ID
>>> 100

# which, with the new folder structure,  is the same as this
$ python manage.py runserver --settings=inte_edc.settings.defaults

>>> from django.conf import settings
>>> setting.SITE_ID
>>> 100

# This loads for a specific site
$ python manage.py runserver --settings=inte_edc.settings.uganda.kojja

>>> from django.conf import settings
>>> setting.SITE_ID
>>> 170

Of course, having a custom settings file is easy, but managing these across multiple deployments can easily lead to code duplication. So let’s backup a bit. What do we need to setup?

1. change manage.py

...
...
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "inte_edc.settings.defaults")
...
...


or to be more helpful ...

def main():
default = "inte_edc.settings.defaults"
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "inte_edc.settings.defaults")
if os.environ.get("DJANGO_SETTINGS_MODULE") == default:
    sys.stderr.write(
        style.ERROR(
            f"DJANGO_SETTINGS_MODULE not set. Using `{default}`. "
            f"Assuming a test environment (manage.py).\n"
        )
    )
try:
    from django.core.management import execute_from_command_line
...
...

2. change wsgi.py

os.environ.setdefault("DJANGO_SETTINGS_MODULE", "inte_edc.settings")

becomes this

os.environ.setdefault("DJANGO_SETTINGS_MODULE", "inte_edc.settings.defaults")

3. create a custom sites module that has a sites.py. In this case inte_sites.sites;

fqdn = "inte.clinicedc.org"

all_sites = {
    "tanzania":(
        (10, "hindu_mandal", "Hindu Mandal Hospital"),
        (20, "amana", "Amana Hospital"),
    ),
    "uganda":(
        (10, "kojja", "Kojja Clinic"),
        (20, "mbarara", "Mbarara Clinic"),
        (30, "kampala", "Kampala Clinic"),
    ),
}

4. move settings.py to a folder and put all settings stuff in a defaults.py:

   inte-edc/
       inte_edc/
           settings/
               __init__.py
               defaults.py
               uganda/
                   __init__.py
                   kampala.py
                   kojja.py
                   mbarara.py
           __init__.py
           wsgi.py
       inte_sites/
           __init__.py
           apps.py
           sites.py
   manage.py

5. create dummy settings files for each site, for example;

# kojja.py
from ..defaults import *  # noqa

4. update the settings defaults.py file. Replace SITE_ID=<site_id> …

# defaults.py
from edc_sites import get_site_from_environment

...

# extract country and sitename from DJANGO_SETTINGS_MODULE environment variable
EDC_SITES_MODULE_NAME = env.str("EDC_SITES_MODULE_NAME")
COUNTRY, SITE_ID, _ = get_site_from_environment(
    default_site_name="mbarara",
    default_country="uganda",
    app_name=APP_NAME,
    sites_module_name=EDC_SITES_MODULE_NAME,
)

...

we choose "mbarara" and "uganda" for our default site_name and country.

5. We use a .env file and set EDC_SITES_MODULE_NAME to inte_sites.sites.

6. set the DJANGO_SETTINGS_MODULE for each environment the project is loaded in.

Unless we are testing, we’ll expect the DJANGO_SETTINGS_MODULE to be set. We’ll set it to a value that includes the county and site name. As you can see from the change to defaults.py above, we parse the value using get_site_from_environment.