from django.contrib.sites.shortcuts import get_current_site
from django.utils.functional import SimpleLazyObject

def site(request):
    site = SimpleLazyObject(lambda: get_current_site(request))
    protocol = 'https' if request.is_secure() else 'http'

    return {
        'site': site,
        'site_root': SimpleLazyObject(lambda: "{0}://{1}".format(protocol, site.domain)),
        'full_url': SimpleLazyObject(lambda: "{0}://{1}{2}".format(protocol, site.domain, request.path)),
    }

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [os.path.join(BASE_DIR, "templates")],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
            ...
            'ruta.al.context_processors. site'
            ...
            ],