feat: start pgo pool from kura config and auto-generate UUIDs

src/kura_app.erl

@@ -7,11 +7,38 @@
 start(_StartType, _StartArgs) ->
     configure_pg_types(),
     kura_query_cache:init(),
+    ok = ensure_pool(),
     kura_sup:start_link().
 
 stop(_State) ->
     ok.
 
+-spec ensure_pool() -> ok.
+ensure_pool() ->
+    case application:get_env(kura, repo) of
+        {ok, Repo} ->
+            Config = pool_config(),
+            case pgo_sup:start_child(Repo, Config) of
+                {ok, _Pid} -> ok;
+                {error, {already_started, _Pid}} -> ok
+            end;
+        undefined ->
+            ok
+    end.
+
+-spec pool_config() -> map().
+pool_config() ->
+    Env = fun(Key, Default) -> application:get_env(kura, Key, Default) end,
+    #{
+        host => Env(host, "localhost"),
+        port => Env(port, 5432),
+        database => Env(database, "postgres"),
+        user => Env(user, "postgres"),
+        password => Env(password, ""),
+        pool_size => Env(pool_size, 10),
+        decode_opts => [return_rows_as_maps, column_name_as_atom]
+    }.
+
 -spec configure_pg_types() -> ok.
 configure_pg_types() ->
     Defaults = #{uuid_format => string},

src/kura_repo.erl

@@ -58,13 +58,33 @@ init(Config) ->
 -doc "Read the repo configuration from application environment.".
 -spec config(module()) -> map().
 config(RepoMod) ->
-    App = RepoMod:otp_app(),
-    Config =
-        case application:get_env(App, RepoMod) of
-            {ok, C} when is_map(C) -> C;
-            _ -> #{}
-        end,
+    Config = read_config(RepoMod),
     case erlang:function_exported(RepoMod, init, 1) of
         true -> RepoMod:init(Config);
         false -> Config
     end.
+
+-spec read_config(module()) -> map().
+read_config(RepoMod) ->
+    %% Try kura app env first, fall back to repo's otp_app env for
+    %% backward compatibility.
+    case application:get_env(kura, repo) of
+        {ok, RepoMod} ->
+            Env = fun(Key, Default) ->
+                application:get_env(kura, Key, Default)
+            end,
+            #{
+                hostname => list_to_binary(Env(host, "localhost")),
+                port => Env(port, 5432),
+                database => list_to_binary(Env(database, "postgres")),
+                username => list_to_binary(Env(user, "postgres")),
+                password => list_to_binary(Env(password, "")),
+                pool_size => Env(pool_size, 10)
+            };
+        _ ->
+            App = RepoMod:otp_app(),
+            case application:get_env(App, RepoMod) of
+                {ok, C} when is_map(C) -> C;
+                _ -> #{}
+            end
+    end.