[1371] Add Custom Hostname and Domain Options (#1372)

When using `longnames` in projects that don't
adhere to the host provided hostname and domain
it is useful to be able to override those via the
`erlang_ls.config` file.  The code in this commit
provides these options as well as cleans up
some related duplicated code.

This code also fixes a small bug that would leave
a trailing dot `.` if a domain is not defined.

Tests have been updated to reflect these changes and
new tests have been created to test the new options.

apps/els_core/src/els_config_runtime.erl

@@ -8,6 +8,8 @@
 %% Getters
 -export([
     get_node_name/0,
+    get_hostname/0,
+    get_domain/0,
     get_otp_path/0,
     get_start_cmd/0,
     get_start_args/0,
@@ -20,6 +22,8 @@
 -spec default_config() -> config().
 default_config() ->
     #{
+        "hostname" => default_hostname(),
+        "domain" => default_domain(),
         "node_name" => default_node_name(),
         "otp_path" => default_otp_path(),
         "start_cmd" => default_start_cmd(),
@@ -31,6 +35,17 @@ get_node_name() ->
     Value = maps:get("node_name", els_config:get(runtime), default_node_name()),
     els_utils:compose_node_name(Value, get_name_type()).
 
+-spec get_hostname() -> string().
+get_hostname() ->
+    case els_config:get(runtime) of
+        undefined -> default_hostname();
+        Runtime -> maps:get("hostname", Runtime, default_hostname())
+    end.
+
+-spec get_domain() -> string().
+get_domain() ->
+    maps:get("domain", els_config:get(runtime), default_domain()).
+
 -spec get_otp_path() -> string().
 get_otp_path() ->
     maps:get("otp_path", els_config:get(runtime), default_otp_path()).
@@ -65,12 +80,21 @@ get_cookie() ->
 -spec default_node_name() -> string().
 default_node_name() ->
     RootUri = els_config:get(root_uri),
-    {ok, Hostname} = inet:gethostname(),
+    Hostname = get_hostname(),
     NodeName = els_distribution_server:normalize_node_name(
         filename:basename(els_uri:path(RootUri))
     ),
     NodeName ++ "@" ++ Hostname.
 
+-spec default_hostname() -> string().
+default_hostname() ->
+    {ok, Hostname} = inet:gethostname(),
+    Hostname.
+
+-spec default_domain() -> string().
+default_domain() ->
+    proplists:get_value(domain, inet:get_rc(), "").
+
 -spec default_otp_path() -> string().
 default_otp_path() ->
     filename:dirname(filename:dirname(code:root_dir())).

apps/els_core/src/els_distribution_server.erl

@@ -18,7 +18,6 @@
     rpc_call/3,
     rpc_call/4,
     node_name/2,
-    node_name/3,
     normalize_node_name/1
 ]).
 
@@ -223,15 +222,7 @@ node_name(Prefix, Name0) ->
     Name = normalize_node_name(Name0),
     Int = erlang:phash2(erlang:timestamp()),
     Id = lists:flatten(io_lib:format("~s_~s_~p", [Prefix, Name, Int])),
-    {ok, HostName} = inet:gethostname(),
-    node_name(Id, HostName, els_config_runtime:get_name_type()).
-
--spec node_name(string(), string(), 'longnames' | 'shortnames') -> atom().
-node_name(Id, HostName, shortnames) ->
-    list_to_atom(Id ++ "@" ++ HostName);
-node_name(Id, HostName, longnames) ->
-    Domain = proplists:get_value(domain, inet:get_rc(), ""),
-    list_to_atom(Id ++ "@" ++ HostName ++ "." ++ Domain).
+    els_utils:compose_node_name(Id, els_config_runtime:get_name_type()).
 
 -spec normalize_node_name(string() | binary()) -> string().
 normalize_node_name(Name) ->

apps/els_core/src/els_utils.erl

@@ -453,15 +453,18 @@ compose_node_name(Name, Type) ->
             true ->
                 Name;
             _ ->
-                {ok, HostName} = inet:gethostname(),
+                HostName = els_config_runtime:get_hostname(),
                 Name ++ [$@ | HostName]
         end,
     case Type of
         shortnames ->
             list_to_atom(NodeName);
         longnames ->
-            Domain = proplists:get_value(domain, inet:get_rc(), ""),
-            list_to_atom(NodeName ++ "." ++ Domain)
+            Domain = els_config_runtime:get_domain(),
+            case Domain of
+                "" -> list_to_atom(NodeName);
+                _ -> list_to_atom(NodeName ++ "." ++ Domain)
+            end
     end.
 
 %% @doc Given an MFA or a FA, return a printable version of the

apps/els_dap/src/els_dap_general_provider.erl

@@ -1023,22 +1023,6 @@ safe_eval(ProjectNode, Debugged, Expression, Update) ->
     end,
     Return.
 
--spec check_project_node_name(binary(), boolean()) -> atom().
-check_project_node_name(ProjectNode, false) ->
-    binary_to_atom(ProjectNode, utf8);
-check_project_node_name(ProjectNode, true) ->
-    case binary:match(ProjectNode, <<"@">>) of
-        nomatch ->
-            {ok, HostName} = inet:gethostname(),
-            BinHostName = list_to_binary(HostName),
-            DomainStr = proplists:get_value(domain, inet:get_rc(), ""),
-            Domain = list_to_binary(DomainStr),
-            BinName = <<ProjectNode/binary, "@", BinHostName/binary, ".", Domain/binary>>,
-            binary_to_atom(BinName, utf8);
-        _ ->
-            binary_to_atom(ProjectNode, utf8)
-    end.
-
 -spec start_distribution(map()) -> {ok, map()} | {error, any()}.
 start_distribution(Params) ->
     #{<<"cwd">> := Cwd} = Params,
@@ -1062,23 +1046,21 @@ start_distribution(Params) ->
         <<"cookie">> := ConfCookie,
         <<"use_long_names">> := UseLongNames
     } = Config,
-    ConfProjectNode = check_project_node_name(RawProjectNode, UseLongNames),
-    ?LOG_INFO("Configured Project Node Name: ~p", [ConfProjectNode]),
-    Cookie = binary_to_atom(ConfCookie, utf8),
-
     NameType =
         case UseLongNames of
             true ->
                 longnames;
             false ->
                 shortnames
         end,
+
+    ConfProjectNode0 = binary_to_list(RawProjectNode),
+    ConfProjectNode = els_utils:compose_node_name(ConfProjectNode0, NameType),
+    ?LOG_INFO("Configured Project Node Name: ~p", [ConfProjectNode]),
+    Cookie = binary_to_atom(ConfCookie, utf8),
+
     %% start distribution
-    Prefix = <<"erlang_ls_dap">>,
-    Int = erlang:phash2(erlang:timestamp()),
-    Id = lists:flatten(io_lib:format("~s_~s_~p", [Prefix, Name, Int])),
-    {ok, HostName} = inet:gethostname(),
-    LocalNode = els_distribution_server:node_name(Id, HostName, NameType),
+    LocalNode = els_distribution_server:node_name(<<"erlang_ls_dap">>, Name),
     case
         els_distribution_server:start_distribution(
             LocalNode,

apps/els_lsp/test/els_diagnostics_SUITE.erl

@@ -28,6 +28,8 @@
     compiler_telemetry/1,
     code_path_extra_dirs/1,
     use_long_names/1,
+    use_long_names_no_domain/1,
+    use_long_names_custom_hostname/1,
     epp_with_nonexistent_macro/1,
     code_reload/1,
     code_reload_sticky_mod/1,
@@ -120,15 +122,20 @@ init_per_testcase(code_path_extra_dirs, Config) ->
     els_mock_diagnostics:setup(),
     els_test_utils:init_per_testcase(code_path_extra_dirs, Config);
 init_per_testcase(use_long_names, Config) ->
-    meck:new(yamerl, [passthrough, no_link]),
+    Content =
+        <<"runtime:\n", "  use_long_names: true\n", "  cookie: mycookie\n",
+            "  node_name: my_node\n", "  domain: test.local">>,
+    init_long_names_config(Content, Config);
+init_per_testcase(use_long_names_no_domain, Config) ->
     Content =
         <<"runtime:\n", "  use_long_names: true\n", "  cookie: mycookie\n",
             "  node_name: my_node\n">>,
-    meck:expect(yamerl, decode_file, 2, fun(_, Opts) ->
-        yamerl:decode(Content, Opts)
-    end),
-    els_mock_diagnostics:setup(),
-    els_test_utils:init_per_testcase(code_path_extra_dirs, Config);
+    init_long_names_config(Content, Config);
+init_per_testcase(use_long_names_custom_hostname, Config) ->
+    Content =
+        <<"runtime:\n", "  use_long_names: true\n", "  cookie: mycookie\n",
+            "  node_name: my_node\n", "  hostname: 127.0.0.1">>,
+    init_long_names_config(Content, Config);
 init_per_testcase(exclude_unused_includes = TestCase, Config) ->
     els_mock_diagnostics:setup(),
     NewConfig = els_test_utils:init_per_testcase(TestCase, Config),
@@ -224,7 +231,9 @@ end_per_testcase(TestCase, Config) when
     ok;
 end_per_testcase(TestCase, Config) when
     TestCase =:= code_path_extra_dirs orelse
-        TestCase =:= use_long_names
+        TestCase =:= use_long_names orelse
+        TestCase =:= use_long_names_no_domain orelse
+        TestCase =:= use_long_names_custom_hostname
 ->
     meck:unload(yamerl),
     els_test_utils:end_per_testcase(code_path_extra_dirs, Config),
@@ -271,6 +280,15 @@ end_per_testcase(TestCase, Config) ->
     els_mock_diagnostics:teardown(),
     ok.
 
+-spec init_long_names_config(binary(), config()) -> config().
+init_long_names_config(Content, Config) ->
+    meck:new(yamerl, [passthrough, no_link]),
+    meck:expect(yamerl, decode_file, 2, fun(_, Opts) ->
+        yamerl:decode(Content, Opts)
+    end),
+    els_mock_diagnostics:setup(),
+    els_test_utils:init_per_testcase(code_path_extra_dirs, Config).
+
 % RefactorErl
 
 %%==============================================================================
@@ -626,12 +644,30 @@ code_path_extra_dirs(_Config) ->
 
 -spec use_long_names(config()) -> ok.
 use_long_names(_Config) ->
-    {ok, HostName} = inet:gethostname(),
+    HostName = els_config_runtime:get_hostname(),
     NodeName =
         "my_node@" ++
             HostName ++ "." ++
-            proplists:get_value(domain, inet:get_rc(), ""),
+            els_config_runtime:get_domain(),
+    Node = list_to_atom(NodeName),
+    ?assertMatch(Node, els_config_runtime:get_node_name()),
+    ok.
+
+-spec use_long_names_no_domain(config()) -> ok.
+use_long_names_no_domain(_Config) ->
+    HostName = els_config_runtime:get_hostname(),
+    NodeName =
+        "my_node@" ++ HostName,
+    Node = list_to_atom(NodeName),
+    ?assertMatch(Node, els_config_runtime:get_node_name()),
+    ok.
+
+-spec use_long_names_custom_hostname(config()) -> ok.
+use_long_names_custom_hostname(_Config) ->
+    HostName = els_config_runtime:get_hostname(),
+    NodeName = "[email protected]",
     Node = list_to_atom(NodeName),
+    ?assertMatch(HostName, "127.0.0.1"),
     ?assertMatch(Node, els_config_runtime:get_node_name()),
     ok.