The response cache plug can cache an entire response body for a set amount of time.

To enable the cache, add the plug to your pipeline as early as possible. Here’s what that looks like in a clean Phoenix installation:

pipeline :browser do
  plug(:accepts, ["html"])
  plug(PlugResponseCache)
  plug(:fetch_session)
  plug(:fetch_flash)
  plug(:protect_from_forgery)
  plug(:put_secure_browser_headers)
end

The plug should be configured with the :plug_response_cache config key. This belongs in your application’s configuration file:

config :plug_response_cache,
  enabled: false,
  store: MyApp.ResponseCache.MyCustomStore
  profile: MyApp.ResponseCache.MyCustomProfile

• enabled: Enables or disables the response cache entirely (default: true)
• store: A custom cache store — a module that implements PlugResponseCache.Store callbacks (default: PlugResponseCache.Stores.Ets)
• profile: A custom cache profile — a module that implements PlugResponseCache.Profile callbacks (default: PlugResponseCache.Profiles.Default)
• debug: Logs the response cache’s result on every request when true (default: false)

Since every option has a default, the response cache will also work without specifying any custom configuration.

Options are also passed to the cache profile, so if a profile has options simply add them to the list. For example, the default profile (PlugResponseCache.Profiles.Default) has an expiration_time option to determine for how many minutes the response should be cached.

config :plug_response_cache,
  expiration_time: 5

It’s also possible to pass options to the plug. This is useful for enabling or disabling the response cache on the fly, or for toggling the debug mode.

pipeline :browser do
  # ...
  plug(PlugResponseCache, debug: true)
  # ...
end

It’s not recommended to configure the profile & store like this because they might require a supervisor, which needs to be known ahead of time.