Support HTTP-API for fetching reload result. v5.0.176 (#3779)

During a Reload, several stages will be passed through:
1. Parsing new configurations: Parse.
2. Transforming configurations: Transform.
3. Applying configurations: Apply.

Previously, any error at any stage would result in a direct exit, making
the system completely dependent on configuration checks:

```bash
./objs/srs -c conf/srs.conf -t
echo $?
```

Optimized to: If an error occurs before applying the configuration, it
can be ignored. If an error occurs during the application of the
configuration, some of the configuration may have already taken effect,
leading to unpredictable behavior, so SRS will exit directly.

Added a new HTTP API to query the result of the reload.

```nginx
http_api {
    enabled         on;
    raw_api {
        enabled on;
        allow_reload on;
    }
}
```

```bash
curl http://localhost:1985/api/v1/raw?rpc=reload-fetch
```

```json
{
  "code": 0,
  "data": {
    "err": 0,
    "msg": "Success",
    "state": 0,
    "rid": "0s6y0n9"
  }
}

{
  "code": 0,
  "data": {
    "err": 1023,
    "msg": "code=1023(ConfigInvalid) : parse file : parse buffer containers/conf/srs.release-local.conf : root parse : parse dir : parse include buffer containers/data/config/srs.vhost.conf : read token, line=0, state=0 : line 3: unexpected end of file, expecting ; or \"}\"",
    "state": 1,
    "rid": "0g4z471"
  }
}
```

This way, you can know if the last reload of the system was successful.

---------

Co-authored-by: Haibo Chen <495810242@qq.com>

Dockerfile

@@ -41,7 +41,7 @@ ARG TARGETPLATFORM
 RUN echo "BUILDPLATFORM: $BUILDPLATFORM, TARGETPLATFORM: $TARGETPLATFORM"
 
 # Expose ports for streaming @see https://github.com/ossrs/srs#ports
-EXPOSE 1935 1985 8080 8000/udp 10080/udp
+EXPOSE 1935 1985 8080 5060 9000 8000/udp 10080/udp
 
 # FFMPEG 4.1
 COPY --from=build /usr/local/bin/ffmpeg /usr/local/srs/objs/ffmpeg/bin/ffmpeg

trunk/conf/full.conf

@@ -647,8 +647,8 @@ stream_caster {
     # The available variables:
     #           [stream] The video channel codec ID.
     output rtmp://127.0.0.1/live/[stream];
-    # The listen TCP/UDP port for stream converter.
-    #       For gb28181 converter, listen at TCP/UDP port. for example, 9000.
+    # The listen TCP port for stream converter.
+    #       For gb28181 converter, listen at TCP port. for example, 9000.
     # @remark We always enable bundle for media streams at this port.
     listen 9000;
     # SIP server for GB28181. Please note that this is only a demonstrated SIP server, please never use it in your
@@ -658,7 +658,7 @@ stream_caster {
         # Whether enable embedded SIP server.
         # Default: on
         enabled on;
-        # The SIP listen port, for both TCP and UDP protocol.
+        # The SIP listen port, for TCP protocol.
         # Default: 5060
         listen 5060;
         # The SIP or media transport timeout in seconds.

trunk/doc/CHANGELOG.md

@@ -7,6 +7,7 @@ The changelog for SRS.
 <a name="v5-changes"></a>
 
 ## SRS 5.0 Changelog
+* v5.0, 2023-08-30, Merge [#3779](https://github.com/ossrs/srs/pull/3779): Support HTTP-API for fetching reload result. v5.0.176 (#3779)
 * v5.0, 2023-08-28, Merge [#3503](https://github.com/ossrs/srs/pull/3503): SrsContextId assignment can be improved without create a duplicated one. v5.0.175 (#3503)
 * v5.0, 2023-08-28, Merge [#3781](https://github.com/ossrs/srs/pull/3781): HLS: Fix on_hls and hls_dispose critical zone issue. v5.0.174 (#3781)
 * v5.0, 2023-08-28, Merge [#3768](https://github.com/ossrs/srs/pull/3768): Support include empty config file. v5.0.173 (#3768)

trunk/src/app/srs_app_config.cpp

@@ -1333,18 +1333,22 @@ void SrsConfig::unsubscribe(ISrsReloadHandler* handler)
 }
 
 // LCOV_EXCL_START
-srs_error_t SrsConfig::reload()
+srs_error_t SrsConfig::reload(SrsReloadState *pstate)
 {
+    *pstate = SrsReloadStateInit;
+
     srs_error_t err = srs_success;
-    
+
     SrsConfig conf;
-    
+
+    *pstate = SrsReloadStateParsing;
     if ((err = conf.parse_file(config_file.c_str())) != srs_success) {
         return srs_error_wrap(err, "parse file");
     }
     srs_info("config reloader parse file success.");
     
     // transform config to compatible with previous style of config.
+    *pstate = SrsReloadStateTransforming;
     if ((err = srs_config_transform_vhost(conf.root)) != srs_success) {
         return srs_error_wrap(err, "transform config");
     }
@@ -1352,11 +1356,13 @@ srs_error_t SrsConfig::reload()
     if ((err = conf.check_config()) != srs_success) {
         return srs_error_wrap(err, "check config");
     }
-    
+
+    *pstate = SrsReloadStateApplying;
     if ((err = reload_conf(&conf)) != srs_success) {
         return srs_error_wrap(err, "reload config");
     }
-    
+
+    *pstate = SrsReloadStateFinished;
     return err;
 }
 // LCOV_EXCL_STOP

trunk/src/app/srs_app_config.hpp

@@ -256,6 +256,19 @@ private:
     virtual srs_error_t read_token(srs_internal::SrsConfigBuffer* buffer, std::vector<std::string>& args, int& line_start, SrsDirectiveState& state);
 };
 
+// The state for reloading config.
+enum SrsReloadState {
+    SrsReloadStateInit = 0,
+    // Start to parse the new config file.
+    SrsReloadStateParsing = 10,
+    // Start to transform the new config file to new version.
+    SrsReloadStateTransforming = 20,
+    // Start to apply the new config file.
+    SrsReloadStateApplying = 30,
+    // The reload is finished.
+    SrsReloadStateFinished = 90,
+};
+
 // The config service provider.
 // For the config supports reload, so never keep the reference cross st-thread,
 // that is, never save the SrsConfDirective* get by any api of config,
@@ -308,7 +321,7 @@ public:
     virtual void unsubscribe(ISrsReloadHandler* handler);
     // Reload  the config file.
     // @remark, user can test the config before reload it.
-    virtual srs_error_t reload();
+    virtual srs_error_t reload(SrsReloadState *pstate);
 private:
     // Reload  the vhost section of config.
     virtual srs_error_t reload_vhost(SrsConfDirective* old_root);

trunk/src/app/srs_app_http_api.cpp

@@ -863,7 +863,7 @@ srs_error_t SrsGoApiClients::serve_http(ISrsHttpResponseWriter* w, ISrsHttpMessa
             }
         } else {
             SrsJsonObject* data = SrsJsonAny::object();
-            obj->set("client", data);;
+            obj->set("client", data);
             
             if ((err = client->dumps(data)) != srs_success) {
                 int code = srs_error_code(err);
@@ -907,6 +907,10 @@ SrsGoApiRaw::~SrsGoApiRaw()
     _srs_config->unsubscribe(this);
 }
 
+extern srs_error_t _srs_reload_err;
+extern SrsReloadState _srs_reload_state;
+extern std::string _srs_reload_id;
+
 srs_error_t SrsGoApiRaw::serve_http(ISrsHttpResponseWriter* w, ISrsHttpMessage* r)
 {
     srs_error_t err = srs_success;
@@ -937,8 +941,8 @@ srs_error_t SrsGoApiRaw::serve_http(ISrsHttpResponseWriter* w, ISrsHttpMessage*
     
     //////////////////////////////////////////////////////////////////////////
     // the rpc is required.
-    // the allowd rpc method check.
-    if (rpc.empty() || rpc != "reload") {
+    // the allowed rpc method check.
+    if (rpc.empty() || (rpc != "reload" && rpc != "reload-fetch")) {
         return srs_api_response_code(w, r, ERROR_SYSTEM_CONFIG_RAW);
     }
     
@@ -950,6 +954,16 @@ srs_error_t SrsGoApiRaw::serve_http(ISrsHttpResponseWriter* w, ISrsHttpMessage*
         
         server->on_signal(SRS_SIGNAL_RELOAD);
         return srs_api_response_code(w, r, ERROR_SUCCESS);
+    } else if (rpc == "reload-fetch") {
+        SrsJsonObject* data = SrsJsonAny::object();
+        obj->set("data", data);
+
+        data->set("err", SrsJsonAny::integer(srs_error_code(_srs_reload_err)));
+        data->set("msg", SrsJsonAny::str(srs_error_summary(_srs_reload_err).c_str()));
+        data->set("state", SrsJsonAny::integer(_srs_reload_state));
+        data->set("rid", SrsJsonAny::str(_srs_reload_id.c_str()));
+
+        return srs_api_response(w, r, obj->dumps());
     }
     
     return err;

trunk/src/app/srs_app_server.cpp

@@ -870,7 +870,9 @@ srs_error_t SrsServer::cycle()
     }
 
     // Do server main cycle.
-     err = do_cycle();
+    if ((err = do_cycle()) != srs_success) {
+        srs_error("server err %s", srs_error_desc(err).c_str());
+    }
 
     // OK, SRS server is done.
     wg_->done();
@@ -942,6 +944,10 @@ void SrsServer::on_signal(int signo)
     }
 }
 
+srs_error_t _srs_reload_err;
+SrsReloadState _srs_reload_state;
+std::string _srs_reload_id;
+
 srs_error_t SrsServer::do_cycle()
 {
     srs_error_t err = srs_success;
@@ -991,12 +997,27 @@ srs_error_t SrsServer::do_cycle()
         // do reload the config.
         if (signal_reload) {
             signal_reload = false;
-            srs_info("get signal to reload the config.");
-
-            if ((err = _srs_config->reload()) != srs_success) {
-                return srs_error_wrap(err, "config reload");
+            srs_trace("starting reload config.");
+
+            SrsReloadState state = SrsReloadStateInit;
+            _srs_reload_state = SrsReloadStateInit; srs_freep(_srs_reload_err); _srs_reload_id = srs_random_str(7);
+            err = _srs_config->reload(&state);
+            _srs_reload_state = state; _srs_reload_err = srs_error_copy(err);
+            if (err != srs_success) {
+                // If the parsing and transformation of the configuration fail, we can tolerate it by simply
+                // ignoring the new configuration and continuing to use the current one. However, if the
+                // application of the new configuration fails, some configurations may be applied while
+                // others may not. For instance, the listening port may be closed when the configuration
+                // is set to listen on an unavailable port. In such cases, we should terminate the service.
+                if (state == SrsReloadStateApplying) {
+                    return srs_error_wrap(err, "reload fatal error state=%d", state);
+                }
+
+                srs_warn("reload failed, state=%d, err %s", state, srs_error_desc(err).c_str());
+                srs_freep(err);
+            } else {
+                srs_trace("reload config success, state=%d.", state);
             }
-            srs_trace("reload config success.");
         }
 
         srs_usleep(1 * SRS_UTIME_SECONDS);

trunk/src/app/srs_app_threads.cpp

@@ -295,6 +295,10 @@ srs_error_t SrsCircuitBreaker::on_timer(srs_utime_t interval)
 SrsCircuitBreaker* _srs_circuit_breaker = NULL;
 SrsAsyncCallWorker* _srs_dvr_async = NULL;
 
+extern srs_error_t _srs_reload_err;
+extern SrsReloadState _srs_reload_state;
+extern std::string _srs_reload_id;
+
 srs_error_t srs_global_initialize()
 {
     srs_error_t err = srs_success;
@@ -446,6 +450,10 @@ srs_error_t srs_global_initialize()
     _srs_apm = new SrsApmClient();
 #endif
 
+    _srs_reload_err = srs_success;
+    _srs_reload_state = SrsReloadStateInit;
+    _srs_reload_id = srs_random_str(7);
+
     return err;
 }
 

trunk/src/core/srs_core_version5.hpp

@@ -9,6 +9,6 @@
 
 #define VERSION_MAJOR       5
 #define VERSION_MINOR       0
-#define VERSION_REVISION    175
+#define VERSION_REVISION    176
 
 #endif