Add the sync server task.

lib/decentralised_book_index/metadata.ex

@@ -62,7 +62,13 @@ defmodule DecentralisedBookIndex.Metadata do
       define :destroy_author, action: :destroy
     end
 
-    resource DecentralisedBookIndex.Metadata.DBIServer
+    resource DecentralisedBookIndex.Metadata.DBIServer do
+      define :create_dbi_server, action: :create
+      define :list_dbi_server, action: :read
+      define :get_dbi_server_by_id, args: [:id], action: :by_id
+      define :update_dbi_server, action: :update
+      define :destroy_dbi_server, action: :destroy
+    end
 
     resource DecentralisedBookIndex.Metadata.AuthorAliasRegistry do
       define :create_author_alias_registry, action: :create

lib/decentralised_book_index/metadata/dbi_server.ex

@@ -23,6 +23,12 @@ defmodule DecentralisedBookIndex.Metadata.DBIServer do
       primary? true
       accept [:name, :url]
     end
+
+    read :by_id do
+      argument :id, :uuid, allow_nil?: false
+      get? true
+      filter expr(id == ^arg(:id))
+    end
   end
 
   attributes do

lib/decentralised_book_index/sync/sync_tasks/sync_server_task.ex

@@ -0,0 +1,23 @@
+defmodule DecentralisedBookIndex.Sync.SyncServerTask do
+  alias DecentralisedBookIndex.Metadata
+  alias DecentralisedBookIndex.Metadata.DBIServer
+
+  alias DecentralisedBookIndex.SyncTasks.SyncAuthorsTask
+
+  def sync_all() do
+    {:ok, servers} = Metadata.list_dbi_server()
+
+    for server <- servers do
+      sync_one(server)
+    end
+
+    :ok
+  end
+
+  def sync_one(%DBIServer{} = server) do
+    server
+    |> SyncAuthorsTask.sync()
+
+    :ok
+  end
+end