MXS-1220: Treat service listeners as service sub-resources

The listeners under the /services/:service/listeners collection are now
fully JSON API compliant resources.

The listeners could also be exposed as a /listeners collection to easily
group all listener type resources in one place. This approach does has
some semantical and practical problems, namely the fact that each listener
has a many-to-one relationship with its service and listeners by
themselves can't exist alone.

include/maxscale/service.h

@@ -304,6 +304,16 @@ json_t* service_to_json(const SERVICE* service, const char* host);
  */
 json_t* service_list_to_json(const char* host);
 
+/**
+ * @brief Convert service listeners to JSON
+ *
+ * @param service Service whose listeners are converted
+ * @param host    Hostname of this server
+ *
+ * @return Array of JSON format listeners
+ */
+json_t* service_listeners_to_json(const SERVICE* service, const char* host);
+
 /**
  * @brief Get links to services that relate to a server
  *

server/core/json_api.cc

@@ -32,7 +32,7 @@ static json_t* self_link(const char* host, const char* endpoint)
 
 json_t* mxs_json_resource(const char* host, const char* self, json_t* data)
 {
-    ss_dassert(data && (json_is_array(data) || json_is_object(data)));
+    ss_dassert(data && (json_is_array(data) || json_is_object(data) || json_is_null(data)));
     json_t* rval = json_object();
     json_object_set_new(rval, CN_LINKS, self_link(host, self));
     json_object_set_new(rval, CN_DATA, data);

server/core/listener.cc

@@ -514,13 +514,12 @@ bool listener_serialize(const SERV_LISTENER *listener)
 
 json_t* listener_to_json(const SERV_LISTENER* listener)
 {
-    json_t* rval = json_object();
-    json_object_set_new(rval, "name", json_string(listener->name));
-    json_object_set_new(rval, "address", json_string(listener->address));
-    json_object_set_new(rval, "port", json_integer(listener->port));
-    json_object_set_new(rval, "protocol", json_string(listener->protocol));
-    json_object_set_new(rval, "authenticator", json_string(listener->authenticator));
-    json_object_set_new(rval, "auth_options", json_string(listener->auth_options));
+    json_t* param = json_object();
+    json_object_set_new(param, "address", json_string(listener->address));
+    json_object_set_new(param, "port", json_integer(listener->port));
+    json_object_set_new(param, "protocol", json_string(listener->protocol));
+    json_object_set_new(param, "authenticator", json_string(listener->authenticator));
+    json_object_set_new(param, "auth_options", json_string(listener->auth_options));
 
     if (listener->ssl)
     {
@@ -532,8 +531,16 @@ json_t* listener_to_json(const SERV_LISTENER* listener)
         json_object_set_new(ssl, "ssl_ca_cert", json_string(listener->ssl->ssl_ca_cert));
         json_object_set_new(ssl, "ssl_key", json_string(listener->ssl->ssl_key));
 
-        json_object_set_new(rval, "ssl", ssl);
+        json_object_set_new(param, "ssl", ssl);
     }
 
+    json_t* attr = json_object();
+    json_object_set_new(attr, CN_PARAMETERS, param);
+
+    json_t* rval = json_object();
+    json_object_set_new(rval, CN_ATTRIBUTES, attr);
+    json_object_set_new(rval, CN_ID, json_string(listener->name));
+    json_object_set_new(rval, CN_TYPE, json_string(CN_LISTENERS));
+
     return rval;
 }

server/core/resource.cc

@@ -283,15 +283,7 @@ HttpResponse cb_get_service(const HttpRequest& request)
 HttpResponse cb_get_service_listeners(const HttpRequest& request)
 {
     SERVICE* service = service_find(request.uri_part(1).c_str());
-    json_t* json = service_to_json(service, request.host());
-
-    // The 'listeners' key is always defined
-    json_t* listeners = json_incref(json_object_get(json, CN_LISTENERS));
-    ss_dassert(listeners);
-
-    json_decref(json);
-
-    return HttpResponse(MHD_HTTP_OK, listeners);
+    return HttpResponse(MHD_HTTP_OK, service_listeners_to_json(service, request.host()));
 }
 
 HttpResponse cb_all_filters(const HttpRequest& request)

server/core/service.cc

@@ -2459,6 +2459,21 @@ static inline bool have_active_servers(const SERVICE* service)
     return false;
 }
 
+json_t* service_listeners_json_data(const SERVICE* service)
+{
+    json_t* arr = json_array();
+
+    if (service->ports)
+    {
+        for (SERV_LISTENER* p = service->ports; p; p = p->next)
+        {
+            json_array_append_new(arr, listener_to_json(p));
+        }
+    }
+
+    return arr;
+}
+
 json_t* service_attributes(const SERVICE* service)
 {
     json_t* attr = json_object();
@@ -2486,21 +2501,9 @@ json_t* service_attributes(const SERVICE* service)
     json_object_set_new(attr, "total_connections", json_integer(service->stats.n_sessions));
     json_object_set_new(attr, "connections", json_integer(service->stats.n_current));
 
-    /** Add service parameters */
+    /** Add service parameters and listeners */
     json_object_set_new(attr, CN_PARAMETERS, service_parameters_to_json(service));
-
-    /** Add listeners */
-    json_t* arr = json_array();
-
-    if (service->ports)
-    {
-        for (SERV_LISTENER* p = service->ports; p; p = p->next)
-        {
-            json_array_append_new(arr, listener_to_json(p));
-        }
-    }
-
-    json_object_set_new(attr, CN_LISTENERS, arr);
+    json_object_set_new(attr, CN_LISTENERS, service_listeners_json_data(service));
 
     return attr;
 }
@@ -2561,6 +2564,17 @@ json_t* service_to_json(const SERVICE* service, const char* host)
     return mxs_json_resource(host, MXS_JSON_API_SERVICES, service_json_data(service, host));
 }
 
+json_t* service_listeners_to_json(const SERVICE* service, const char* host)
+{
+    /** This needs to be done here as the listeners are sort of sub-resources
+     * of the service. */
+    string self = MXS_JSON_API_SERVICES;
+    self += service->name;
+    self += "/listeners";
+
+    return mxs_json_resource(host, self.c_str(), service_listeners_json_data(service));
+}
+
 json_t* service_list_to_json(const char* host)
 {
     json_t* arr = json_array();

server/core/test/rest-api/test/schema_validation.js

@@ -6,11 +6,14 @@ describe("Resource Collections", function() {
     before(startMaxScale)
 
     var tests = [
-        "/servers/",
-        "/sessions/",
-        "/services/",
-        "/monitors/",
-        "/filters/",
+        "/servers",
+        "/sessions",
+        "/services",
+        "/monitors",
+        "/filters",
+        "/maxscale/threads",
+        "/maxscale/modules",
+        "/maxscale/tasks",
     ]
 
     tests.forEach(function(endpoint) {
@@ -40,10 +43,9 @@ describe("Individual Resources", function() {
         "/filters/Hint",
         "/sessions/1",
         "/maxscale/",
-        "maxscale/threads",
-        "maxscale/logs",
-        "maxscale/tasks",
-        "maxscale/modules",
+        "/maxscale/threads/0",
+        "/maxscale/logs",
+        "/maxscale/modules/readwritesplit",
     ]
 
     tests.forEach(function(endpoint) {