Fetch config options at runtime

lib/mix/tasks/hydrate_clickhouse.ex

@@ -2,7 +2,6 @@ defmodule Mix.Tasks.HydrateClickhouse do
   use Mix.Task
   use Plausible.Repo
   require Logger
-  @hash_key Keyword.fetch!(Application.get_env(:plausible, PlausibleWeb.Endpoint), :secret_key_base) |> binary_part(0, 16)
 
   # coveralls-ignore-start
 
@@ -101,6 +100,7 @@ defmodule Mix.Tasks.HydrateClickhouse do
   end
 
   def hydrate_events(repo, _args \\ []) do
+    hash_key = Keyword.fetch!(Application.get_env(:plausible, PlausibleWeb.Endpoint), :secret_key_base) |> binary_part(0, 16)
     end_time = ~N[2020-05-21 10:46:51]
     total = Repo.aggregate(from(e in Plausible.Event, where: e.timestamp < ^end_time), :count, :id)
 
@@ -114,7 +114,7 @@ defmodule Mix.Tasks.HydrateClickhouse do
       {session_cache, sessions, events} = Enum.reduce(events, {session_cache, [], []}, fn event, {session_cache, sessions, new_events} ->
         found_session = session_cache[event.fingerprint]
         active = is_active?(found_session, event)
-        user_id = SipHash.hash!(@hash_key, event.fingerprint)
+        user_id = SipHash.hash!(hash_key, event.fingerprint)
         clickhouse_event = struct(Plausible.ClickhouseEvent, Map.from_struct(event) |> Map.put(:user_id, user_id))
 
         cond do

lib/plausible/billing/paddle_api.ex

@@ -2,17 +2,17 @@ defmodule Plausible.Billing.PaddleApi do
   @update_preview_endpoint "https://vendors.paddle.com/api/2.0/subscription/preview_update"
   @update_endpoint "https://vendors.paddle.com/api/2.0/subscription/users/update"
   @get_endpoint "https://vendors.paddle.com/api/2.0/subscription/users"
-  @vendor_id Keyword.fetch!(Application.get_env(:plausible, :paddle), :vendor_id)
-  @vendor_auth_code Keyword.fetch!(Application.get_env(:plausible, :paddle), :vendor_auth_code)
   @headers [
     {"Content-type", "application/json"},
     {"Accept", "application/json"}
   ]
 
   def update_subscription_preview(paddle_subscription_id, new_plan_id) do
+    config = get_config()
+
     params = %{
-      vendor_id: @vendor_id,
-      vendor_auth_code: @vendor_auth_code,
+      vendor_id: config[:vendor_id],
+      vendor_auth_code: config[:vendor_auth_code],
       subscription_id: paddle_subscription_id,
       plan_id: new_plan_id,
       prorate: true,
@@ -32,9 +32,11 @@ defmodule Plausible.Billing.PaddleApi do
   end
 
   def update_subscription(paddle_subscription_id, params) do
+    config = get_config()
+
     params = Map.merge(params, %{
-      vendor_id: @vendor_id,
-      vendor_auth_code: @vendor_auth_code,
+      vendor_id: config[:vendor_id],
+      vendor_auth_code: config[:vendor_auth_code],
       subscription_id: paddle_subscription_id,
       quantity: 1
     })
@@ -50,9 +52,10 @@ defmodule Plausible.Billing.PaddleApi do
   end
 
   def get_subscription(paddle_subscription_id) do
+    config = get_config()
     params = %{
-      vendor_id: @vendor_id,
-      vendor_auth_code: @vendor_auth_code,
+      vendor_id: config[:vendor_id],
+      vendor_auth_code: config[:vendor_auth_code],
       subscription_id: paddle_subscription_id
     }
 
@@ -66,4 +69,8 @@ defmodule Plausible.Billing.PaddleApi do
       {:error, body["error"]}
     end
   end
+
+  defp get_config() do
+    Application.get_env(:plausible, :paddle)
+  end
 end

lib/plausible_web/controllers/api/external_controller.ex

@@ -1,7 +1,6 @@
 defmodule PlausibleWeb.Api.ExternalController do
   use PlausibleWeb, :controller
   require Logger
-  @hash_key Keyword.fetch!(Application.get_env(:plausible, PlausibleWeb.Endpoint), :secret_key_base) |> binary_part(0, 16)
 
   def event(conn, _params) do
     params = parse_body(conn)
@@ -98,11 +97,12 @@ defmodule PlausibleWeb.Api.ExternalController do
   end
 
   defp generate_user_id(conn, params) do
+    hash_key = Keyword.fetch!(Application.get_env(:plausible, PlausibleWeb.Endpoint), :secret_key_base) |> binary_part(0, 16)
     user_agent = List.first(Plug.Conn.get_req_header(conn, "user-agent")) || ""
     ip_address = List.first(Plug.Conn.get_req_header(conn, "x-bb-ip")) || "" # Netlify sets this header as the remote client IP
     domain = strip_www(params["domain"]) || ""
 
-    SipHash.hash!(@hash_key, user_agent <> ip_address <> domain)
+    SipHash.hash!(hash_key, user_agent <> ip_address <> domain)
   end
 
   defp calculate_screen_size(nil) , do: nil