Changes between Version 16 and Version 17 of SplitSettings

Timestamp:

Sep 16, 2011, 12:00:14 AM (13 years ago)

Author:

karim.nassar@…

Comment:

--

SplitSettings

@@ -404 +404 @@
 print CONFIGURATION # prints 'cordis'
 }}}
+
+=== Setting Inheritance with Hierarchy ===
+
+I need to be able to inherit from a base settings file, then for each environment provide overrides. In dev env, we need developer specific settings. The following extends [http://djangopeople.net/cordis  Sergey Yushckeyev's] solution above:
+
+{{{settings/__init__.py}}}
+{{{
+#!python
+import os, pwd
+
+# certain keys we want to merge instead of copy
+merge_keys = ('INSTALLED_APPS', 'MIDDLEWARE_CLASSES')
+
+def deep_update(from_dict, to_dict):
+    for (key, value) in from_dict.iteritems():
+        if key in to_dict.keys() and isinstance(to_dict[key], dict) and isinstance(value, dict):
+            deep_update(value, to_dict[key])
+        elif key in merge_keys:
+            if not key in to_dict:
+                to_dict[key] = ()
+            to_dict[key] = to_dict[key] + from_dict[key]
+        else:
+            to_dict[key] = value
+
+# this should be one of prod, qa, staging, dev. default to dev for safety
+env = os.environ.get('APP_ENV', 'dev')
+
+# try to load user specific settings
+uid = pwd.getpwuid(os.getuid())[0]
+
+modules = ('common', env, uid)
+current = __name__
+for module_name in modules:
+    try:
+        module = getattr(__import__(current, globals(), locals(), [module_name]), module_name)
+    except ImportError, e:
+        print 'ERROR: Unable to import %s configuration: %s' % (module_name, e)
+        raise
+    except AttributeError, e:
+        if env == 'dev' and module_name == uid:
+            print 'WARNING: Unable to import %s dev configuration: does %s.py exist?' % (module_name, module_name)
+        else:
+            raise
+
+    # create a local copy of this module's settings
+    module_settings = {}
+    for setting in dir(module):
+        # all django settings are uppercase, so this ensures we
+        # are only processing setting from the dir() call
+        if setting == setting.upper():
+            module_settings[setting] = getattr(module, setting)
+    deep_update(module_settings, locals())
+
+#print locals() # for debugging
+}}}
+
+Then, move {{{settings.py}}} to {{{common.py}}}. 
+
+
+The above defaults to {{{dev}}} env. You could pass in anything to {{{manage.py}}} via the {{{APP_ENV}}} environment variable. Common ones would be {{{prod}}}, {{{staging}}}, {{{qa}}}, etc. For each {{{APP_ENV}}}, you create a file {{{$APP_ENV.py}}}. Finally, create {{{$USER.py}}} file with overrides. Example files (excepting settings.py) below..
+
+{{{dev.py}}}
+{{{
+#!python
+import os
+
+# cwd is settings. determine project path
+cwd = os.path.dirname(os.path.abspath(__file__)) 
+project_path = cwd[:-9] # chop off "settings/"
+
+DEBUG = True
+TEMPLATE_DEBUG = DEBUG
+
+TEMPLATE_DIRS = (
+    # Put strings here, like "/home/html/django_templates" or "C:/www/django/templates".
+    # Always use forward slashes, even on Windows.
+    # Don't forget to use absolute paths, not relative paths.
+
+    # project templates directory
+    '%s/templates' % ( project_path )
+)
+}}}
+
+{{{$USER.py}}}
+{{{
+#!python
+DATABASES = {
+    'default': {
+        'USER': 'me',           
+        'PASSWORD': 'i<3django',
+    }
+}
+
+INSTALLED_APPS = (
+    'haystack',
+)
+
+HAYSTACK_CONNECTIONS = {
+    'default': {
+        'ENGINE': 'haystack.backends.solr_backend.SolrEngine',
+        'URL': 'http://127.0.0.1:8983/solr'
+    },
+}
+}}}