feat(mgmt): add alias endpoint for health check

This allow use to reference `/status` in the API documentation without
manually editing the `swagger.json` file.

apps/emqx_management/i18n/emqx_mgmt_api_status_i18n.conf

@@ -0,0 +1,38 @@
+emqx_mgmt_api_status {
+  get_status_api {
+    desc {
+      en: "Serves as a health check for the node.  Returns a plain text response"
+          " describing the status of the node.  This endpoint requires no"
+          " authentication.\n"
+          "\n"
+          "Returns status code 200 if the EMQX application is up and running, "
+          "503 otherwise."
+          "\n"
+          "The GET `/status` endpoint (without the `/api/...` prefix) is also an alias"
+          " to this endpoint and works in the same way."
+      zh: "作为节点的健康检查。 返回一个纯文本的响应，描述节点的状态。\n"
+          "\n"
+          "如果 EMQX 应用程序已经启动并运行，返回状态代码 200，否则返回 503。\n"
+          "\n"
+          "GET `/status`端点（没有`/api/...`前缀）也是这个端点的一个别名，工作方式相同。"
+    }
+  }
+
+  get_status_response200 {
+    desc {
+      en: "Node emqx@127.0.0.1 is started\n"
+          "emqx is running"
+      zh: "Node emqx@127.0.0.1 is started\n"
+          "emqx is running"
+    }
+  }
+
+  get_status_response503 {
+    desc {
+      en: "Node emqx@127.0.0.1 is stopped\n"
+          "emqx is not_running"
+      zh: "Node emqx@127.0.0.1 is stopped\n"
+          "emqx is not_running"
+    }
+  }
+}

apps/emqx_management/src/emqx_mgmt_api_status.erl

@@ -15,11 +15,50 @@
 %%--------------------------------------------------------------------
 -module(emqx_mgmt_api_status).
 
+-behaviour(minirest_api).
+
+-include_lib("hocon/include/hoconsc.hrl").
+
+%% minirest API
+-export([api_spec/0, paths/0, schema/1]).
+
+-export([get_status/2]).
+
 -export([
     init/2,
     path/0
 ]).
 
+-define(TAGS, [<<"Status">>]).
+
+%%--------------------------------------------------------------------
+%% minirest API and schema
+%%--------------------------------------------------------------------
+
+api_spec() ->
+    emqx_dashboard_swagger:spec(?MODULE, #{check_schema => true}).
+
+paths() ->
+    ["/status"].
+
+schema("/status") ->
+    #{
+        'operationId' => get_status,
+        get => #{
+            description => ?DESC(get_status_api),
+            tags => ?TAGS,
+            security => [],
+            responses => #{
+                200 => ?DESC(get_status_response200),
+                503 => ?DESC(get_status_response503)
+            }
+        }
+    }.
+
+%%--------------------------------------------------------------------
+%% non-minirest (cowboy) API
+%%--------------------------------------------------------------------
+
 %% Note: Because swagger now requires an HTTP prefix (e.g. /api/v5),
 %% but the `/status` does not require this fixed prefix.
 %%
@@ -39,6 +78,9 @@ init(Req0, State) ->
 %% API Handler funcs
 %%--------------------------------------------------------------------
 
+get_status(get, _Params) ->
+    running_status().
+
 running_status() ->
     case emqx_dashboard_listener:is_ready(timer:seconds(20)) of
         true ->

apps/emqx_management/test/emqx_mgmt_api_status_SUITE.erl

@@ -19,6 +19,7 @@
 -compile(nowarn_export_all).
 
 -include_lib("eunit/include/eunit.hrl").
+-include_lib("common_test/include/ct.hrl").
 
 -define(HOST, "http://127.0.0.1:18083/").
 
@@ -27,7 +28,24 @@
 %%---------------------------------------------------------------------------------------
 
 all() ->
-    emqx_common_test_helpers:all(?MODULE).
+    OtherTCs = emqx_common_test_helpers:all(?MODULE) -- get_status_tests(),
+    [
+        {group, api_status_endpoint},
+        {group, non_api_status_endpoint}
+        | OtherTCs
+    ].
+
+get_status_tests() ->
+    [
+        t_status_ok,
+        t_status_not_ok
+    ].
+
+groups() ->
+    [
+        {api_status_endpoint, [], get_status_tests()},
+        {non_api_status_endpoint, [], get_status_tests()}
+    ].
 
 init_per_suite(Config) ->
     emqx_mgmt_api_test_util:init_suite(),
@@ -36,6 +54,16 @@ init_per_suite(Config) ->
 end_per_suite(_) ->
     emqx_mgmt_api_test_util:end_suite().
 
+init_per_group(api_status_endpoint, Config) ->
+    [{get_status_path, ["api", "v5", "status"]} | Config];
+init_per_group(non_api_status_endpoint, Config) ->
+    [{get_status_path, ["status"]} | Config];
+init_per_group(_Group, Config) ->
+    Config.
+
+end_per_group(_Group, _Config) ->
+    ok.
+
 init_per_testcase(t_status_not_ok, Config) ->
     ok = application:stop(emqx),
     Config;
@@ -97,13 +125,14 @@ data_loop(Gun, Ref, Acc) ->
 %% Test cases
 %%---------------------------------------------------------------------------------------
 
-t_status_ok(_Config) ->
+t_status_ok(Config) ->
+    Path = ?config(get_status_path, Config),
     #{
         body := Resp,
         status_code := StatusCode
     } = do_request(#{
         method => get,
-        path => ["status"],
+        path => Path,
         headers => [],
         body => no_body
     }),
@@ -114,14 +143,15 @@ t_status_ok(_Config) ->
     ),
     ok.
 
-t_status_not_ok(_Config) ->
+t_status_not_ok(Config) ->
+    Path = ?config(get_status_path, Config),
     #{
         body := Resp,
         headers := Headers,
         status_code := StatusCode
     } = do_request(#{
         method => get,
-        path => ["status"],
+        path => Path,
         headers => [],
         body => no_body
     }),