避免 django 设置文件中的代码重复

Question

I am following Django settings best practices by using base.py , local.py , prod.py , and staging.py .

My conundrum is whether or not to be okay with code duplication. Let's take this example. I need to set a URL which is used in a large dictionary of fixed values to configure a package.

local.py CONF_URL = 'hard coded local value'

prod.py CONF_URL = os.environ['CONF_URL']

staging.py CONF_URL = 'some other hard coded value'

I then have code like

PACKAGE_CONF = {
  'CONF_URL': CONF_URL,
  'foo1': bar,
  'foo2': bar,
  'foo3': bar,
  'foo4': bar,
  'foo5': bar,
}

• I can't put PACKAGE_CONF in base.py because we import base from the leaf settings files and not the other way around.
• I can write something to post process PACKAGE_CONF like using an env file but that seems unnecessarily complicated.
• I can force the user to take CONF_URL from the environment but that's not a good local dev experience.
• And lastly I can duplicate PACKAGE_CONF in local , staging, and prod .

I'm not super pleased with any of these options. Can someone with experience in writing beautiful settings files offer a better solution?

Answer 1

You can use .env file for setting up the variables of local/dev environment, and ensure you have this same variables set up in staging/prod envs.

.env file values will be used only when the environment var is not present. So, you can push the .env file to your code repo.

In that way, you will be able to write just once your var in base.py file.

Answer 2

The solution I ended up doing is this

in base.py I put

PACKAGE_CONF = {
  'foo1': bar,
  'foo2': bar,
  'foo3': bar,
  'foo4': bar,
  'foo5': bar,
}

And then I override PACKAGE_CONF['CONF_URL'] in the leaf settings files, eg in staging.py

CONF_URL = 'some other hard coded value'
PACKAGE_CONF['CONF_URL'] = CONF_URL

The downside is you might forget to add this value when you create a new leaf settings file and that may lead to unexpected behavior since the dictionary exists but one key is missing.

However, I think this is acceptable since when you create a new leaf settings you usually copy paste an existing one.