There are some situations where you want to block access to an environment such as when you're just staging a project.
For this particular case, using a custom Basic Auth Plug that's conditional on environment variables may be all you need.
Let's get started by create a custom plug and then "plug" it into our system.
It's assumed that you want to restrict access to the entire application in a staging environment.
Basic Auth Plug
First create WEB/controllers/basic_auth.ex with this content:
(Remember to update MyAppWeb)
Next, let's add some simple configuration to config/config.ex:
You can also use environment variables to keep these values out of your repo, but for this simple set up, let's just keep it as is.
Open WEB/router.ex and add the plug to a pipeline:
This will check for the value of APP_DOMAIN and conditionally pipe the connection through the custom plug.
NOTE: Don't forget to actually set APP_DOMAIN in your staging environment.
You can optionally test the new Plug out by passing the environment variable's expected value when you start up the Phoenix server:
$ APP_DOMAIN=staging.myapp.com mix -S phx.server
Then you should see the basic auth prompt to enter the credentials.
This was a very simple strategy for restricting access to a staging environment without adding any dependencies.
This can be expanding and improved upon in many ways but should serve as a basic starting point.