MXS-1220: Make modules proper resources

The /maxscale/modules/ endpoint is now a resource collection and the
/maxscale/modules/:module endpoint exposes the individual resources.

include/maxscale/config.h

@@ -78,6 +78,7 @@ extern const char CN_MAXSCALE[];
 extern const char CN_MAX_CONNECTIONS[];
 extern const char CN_MAX_RETRY_INTERVAL[];
 extern const char CN_MODULE[];
+extern const char CN_MODULES[];
 extern const char CN_MONITORS[];
 extern const char CN_MONITOR[];
 extern const char CN_MS_TIMESTAMP[];

server/core/config.cc

@@ -87,6 +87,7 @@ const char CN_MAXSCALE[]                      = "maxscale";
 const char CN_MAX_CONNECTIONS[]               = "max_connections";
 const char CN_MAX_RETRY_INTERVAL[]            = "max_retry_interval";
 const char CN_MODULE[]                        = "module";
+const char CN_MODULES[]                       = "modules";
 const char CN_MONITORS[]                      = "monitors";
 const char CN_MONITOR[]                       = "monitor";
 const char CN_MS_TIMESTAMP[]                  = "ms_timestamp";

server/core/load_utils.cc

@@ -37,16 +37,17 @@
 #include <unistd.h>
 #include <string.h>
 #include <dlfcn.h>
+#include <curl/curl.h>
+#include <sys/utsname.h>
+#include <openssl/sha.h>
 
 #include <maxscale/modinfo.h>
 #include <maxscale/log_manager.h>
 #include <maxscale/version.h>
 #include <maxscale/notification.h>
-#include <curl/curl.h>
-#include <sys/utsname.h>
-#include <openssl/sha.h>
 #include <maxscale/paths.h>
 #include <maxscale/alloc.h>
+#include <maxscale/json_api.h>
 
 #include "maxscale/modules.h"
 #include "maxscale/config.h"
@@ -406,16 +407,19 @@ void dprintAllModules(DCB *dcb)
     dcb_printf(dcb, "----------------+-----------------+---------+-------+-------------------------\n\n");
 }
 
-static json_t* module_to_json(const LOADED_MODULE *mod, const char* host)
+static json_t* module_json_data(const LOADED_MODULE *mod, const char* host)
 {
     json_t* obj = json_object();
 
-    json_object_set_new(obj, "name", json_string(mod->module));
+    json_object_set_new(obj, CN_ID, json_string(mod->module));
-    json_object_set_new(obj, "type", json_string(mod->type));
+    json_object_set_new(obj, CN_TYPE, json_string(CN_MODULE));
-    json_object_set_new(obj, "version", json_string(mod->info->version));
+
-    json_object_set_new(obj, "description", json_string(mod->info->description));
+    json_t* attr = json_object();
-    json_object_set_new(obj, "api", json_string(mxs_module_api_to_string(mod->info->modapi)));
+    json_object_set_new(attr, "module_type", json_string(mod->type));
-    json_object_set_new(obj, "status", json_string(mxs_module_status_to_string(mod->info->status)));
+    json_object_set_new(attr, "version", json_string(mod->info->version));
+    json_object_set_new(attr, "description", json_string(mod->info->description));
+    json_object_set_new(attr, "api", json_string(mxs_module_api_to_string(mod->info->modapi)));
+    json_object_set_new(attr, "status", json_string(mxs_module_status_to_string(mod->info->status)));
 
     json_t* params = json_array();
 
@@ -447,21 +451,41 @@ static json_t* module_to_json(const LOADED_MODULE *mod, const char* host)
         json_array_append_new(params, p);
     }
 
-    json_object_set_new(obj, CN_PARAMETERS, params);
+    json_object_set_new(attr, CN_PARAMETERS, params);
+    json_object_set_new(obj, CN_ATTRIBUTES, attr);
 
     return obj;
 }
 
+json_t* module_to_json(const MXS_MODULE* module, const char* host)
+{
+    json_t* data = NULL;
+
+    for (LOADED_MODULE *ptr = registered; ptr; ptr = ptr->next)
+    {
+        if (ptr->info == module)
+        {
+            data = module_json_data(ptr, host);
+            break;
+        }
+    }
+
+    // This should always be non-NULL
+    ss_dassert(data);
+
+    return mxs_json_resource(host, MXS_JSON_API_MODULES, data);
+}
+
 json_t* module_list_to_json(const char* host)
 {
     json_t* arr = json_array();
 
     for (LOADED_MODULE *ptr = registered; ptr; ptr = ptr->next)
     {
-        json_array_append_new(arr, module_to_json(ptr, host));
+        json_array_append_new(arr, module_json_data(ptr, host));
     }
 
-    return arr;
+    return mxs_json_resource(host, MXS_JSON_API_MODULES, arr);
 }
 
 void moduleShowFeedbackReport(DCB *dcb)

server/core/maxscale/httprequest.hh

@@ -159,6 +159,16 @@ public:
         return m_resource_parts.size();
     }
 
+   /**
+    * @brief Return the last part of the URI
+    *
+    * @return The last URI part
+    */
+    const std::string last_uri_part() const
+    {
+        return  m_resource_parts.size() > 0 ? m_resource_parts[m_resource_parts.size() - 1] : "";
+    }
+
     const char* host() const
     {
         return m_hostname.c_str();

server/core/maxscale/modules.h

@@ -161,10 +161,21 @@ bool mxs_module_iterator_has_next(const MXS_MODULE_ITERATOR* iterator);
  */
 MXS_MODULE* mxs_module_iterator_get_next(MXS_MODULE_ITERATOR* iterator);
 
+/**
+ * @brief Convert module to JSON
+ *
+ * @param module Module to convert
+ * @param host   Hostname of this server
+ *
+ * @return The module in JSON format
+ */
+json_t* module_to_json(const MXS_MODULE* module, const char* host);
+
 /**
  * @brief Convert all modules to JSON
  *
  * @param host The hostname of this server
+ *
  * @return Array of modules in JSON format
  */
 json_t* module_list_to_json(const char* host);

server/core/resource.cc

@@ -89,7 +89,8 @@ bool Resource::matching_variable_path(const string& path, const string& target)
         if ((path == ":service" && service_find(target.c_str())) ||
             (path == ":server" && server_find_by_unique_name(target.c_str())) ||
             (path == ":filter" && filter_def_find(target.c_str())) ||
-            (path == ":monitor" && monitor_find(target.c_str())))
+            (path == ":monitor" && monitor_find(target.c_str())) ||
+            (path == ":module" && get_module(target.c_str(), NULL)))
         {
             rval = true;
         }
@@ -381,6 +382,12 @@ HttpResponse cb_all_modules(const HttpRequest& request)
     return HttpResponse(MHD_HTTP_OK, module_list_to_json(request.host()));
 }
 
+HttpResponse cb_module(const HttpRequest& request)
+{
+    const MXS_MODULE* module = get_module(request.last_uri_part().c_str(), NULL);
+    return HttpResponse(MHD_HTTP_OK, module_to_json(module, request.host()));
+}
+
 HttpResponse cb_send_ok(const HttpRequest& request)
 {
     return HttpResponse(MHD_HTTP_OK);
@@ -422,6 +429,7 @@ public:
         m_get.push_back(SResource(new Resource(cb_logs, 2, "maxscale", "logs")));
         m_get.push_back(SResource(new Resource(cb_tasks, 2, "maxscale", "tasks")));
         m_get.push_back(SResource(new Resource(cb_all_modules, 2, "maxscale", "modules")));
+        m_get.push_back(SResource(new Resource(cb_module, 3, "maxscale", "modules", ":module")));
 
         /** Create new resources */
         m_post.push_back(SResource(new Resource(cb_flush, 3, "maxscale", "logs", "flush")));