added example cache purge script

lib/pleroma/web/media_proxy/invalidations/http.ex

@@ -0,0 +1,16 @@
+defmodule Pleroma.Web.MediaProxy.Invalidation.Http do
+  @behaviour Pleroma.Web.MediaProxy.Invalidation
+
+  @impl Pleroma.Web.MediaProxy.Invalidation
+  def purge(urls, opts) do
+    method = Map.get(opts, :http_method, :purge)
+    headers = Map.get(opts, :http_headers, [])
+    options = Map.get(opts, :http_options, [])
+
+    Enum.each(urls, fn url ->
+      Pleroma.HTTP.request(method, url, "", headers, options)
+    end)
+
+    {:ok, "success"}
+  end
+end

lib/pleroma/web/media_proxy/invalidations/nginx.ex

@@ -1,12 +0,0 @@
-defmodule Pleroma.Web.MediaProxy.Invalidation.Nginx do
-  @behaviour Pleroma.Web.MediaProxy.Invalidation
-
-  @impl Pleroma.Web.MediaProxy.Invalidation
-  def purge(urls, _opts) do
-    Enum.each(urls, fn url ->
-      Pleroma.HTTP.request(:purge, url, "", [], [])
-    end)
-
-    {:ok, "success"}
-  end
-end

lib/pleroma/web/media_proxy/invalidations/script.ex

@@ -2,9 +2,14 @@ defmodule Pleroma.Web.MediaProxy.Invalidation.Script do
   @behaviour Pleroma.Web.MediaProxy.Invalidation
 
   @impl Pleroma.Web.MediaProxy.Invalidation
-  def purge(urls, %{script_path: script_path} = options) do
-    script_args = List.wrap(Map.get(options, :script_args, []))
-    System.cmd(Path.expand(script_path), [urls] ++ script_args)
+  def purge(urls, %{script_path: script_path} = _options) do
+    args =
+      urls
+      |> List.wrap()
+      |> Enum.uniq()
+      |> Enum.join(" ")
+
+    System.cmd(Path.expand(script_path), [args])
     {:ok, "success"}
   end
 end