SERVER-58506 Expose Server-Parameter Settability

(cherry picked from commit aae909d4cfba1621ccaf5d6168b89a0577d4e0ca)

3 files changed, 84 insertions, 6 deletions

diff --git a/src/mongo/db/commands/parameters.cpp b/src/mongo/db/commands/parameters.cpp
index 8e0802b0c15..33f7e323e32 100644
--- a/src/mongo/db/commands/parameters.cpp
+++ b/src/mongo/db/commands/parameters.cpp
@@ -33,6 +33,7 @@
 
 #include <set>
 
+#include "mongo/bson/bsontypes.h"
 #include "mongo/bson/json.h"
 #include "mongo/bson/mutable/document.h"
 #include "mongo/client/replica_set_monitor.h"
@@ -42,6 +43,7 @@
 #include "mongo/db/commands.h"
 #include "mongo/db/commands/parameters_gen.h"
 #include "mongo/db/storage/storage_options.h"
+#include "mongo/idl/server_parameter_gen.h"
 #include "mongo/logger/logger.h"
 #include "mongo/logger/parse_log_component_settings.h"
 #include "mongo/util/log.h"
@@ -184,6 +186,19 @@ Status setLogComponentVerbosity(const BSONObj& bsonSettings) {
     return Status::OK();
 }
 
+
+GetParameterOptions parseGetParameterOptions(BSONElement elem) {
+    if (elem.type() == BSONType::Object) {
+        return GetParameterOptions::parse({"getParameter"}, elem.Obj());
+    }
+    if ((elem.type() == BSONType::String) && (elem.valueStringDataSafe() == "*"_sd)) {
+        GetParameterOptions ret;
+        ret.setAllParameters(true);
+        return ret;
+    }
+    return GetParameterOptions{};
+}
+
 // for automationServiceDescription
 Mutex autoServiceDescriptorMutex;
 std::string autoServiceDescriptorValue;
@@ -211,27 +226,39 @@ public:
     std::string help() const override {
         std::string h =
             "get administrative option(s)\nexample:\n"
-            "{ getParameter:1, notablescan:1 }\n";
+            "{ getParameter:1, notablescan:1 }\n"
+            "pass a document as the value for getParameter to request options\nexample:\n"
+            "{ getParameter:{showDetails: true}, notablescan:1}\n";
         appendParameterNames(&h);
-        h += "{ getParameter:'*' } to get everything\n";
+        h += "{ getParameter:'*' } or { getParameter:{allParameters: true} } to get everything\n";
         return h;
     }
     bool errmsgRun(OperationContext* opCtx,
                    const string& dbname,
                    const BSONObj& cmdObj,
                    string& errmsg,
-                   BSONObjBuilder& result) {
-        bool all = *cmdObj.firstElement().valuestrsafe() == '*';
+                   BSONObjBuilder& result) override {
+        const auto options = parseGetParameterOptions(cmdObj.firstElement());
+        const bool all = options.getAllParameters();
 
         int before = result.len();
 
         const ServerParameter::Map& m = ServerParameterSet::getGlobal()->getMap();
         for (ServerParameter::Map::const_iterator i = m.begin(); i != m.end(); ++i) {
             if (all || cmdObj.hasElement(i->first.c_str())) {
-                i->second->append(opCtx, result, i->second->name());
+                if (options.getShowDetails()) {
+                    BSONObjBuilder detailBob(result.subobjStart(i->second->name()));
+                    i->second->append(opCtx, detailBob, "value");
+                    detailBob.appendBool("settableAtRuntime",
+                                         i->second->allowedToChangeAtRuntime());
+                    detailBob.appendBool("settableAtStartup",
+                                         i->second->allowedToChangeAtStartup());
+                    detailBob.doneFast();
+                } else {
+                    i->second->append(opCtx, result, i->second->name());
+                }
             }
         }
-
         if (before == result.len()) {
             errmsg = "no option found to get";
             return false;
diff --git a/src/mongo/idl/SConscript b/src/mongo/idl/SConscript
index 0ce5bf975dc..e72dd9ed71e 100644
--- a/src/mongo/idl/SConscript
+++ b/src/mongo/idl/SConscript
@@ -32,10 +32,12 @@ env.Library(
     target='server_parameter',
     source=[
         'server_parameter.cpp',
+        env.Idlc('server_parameter.idl')[0],
         'server_parameter_with_storage.cpp',
     ],
     LIBDEPS=[
         '$BUILD_DIR/mongo/base',
+        'idl_parser',
     ],
     LIBDEPS_PRIVATE=[
         '$BUILD_DIR/mongo/util/options_parser/options_parser',
diff --git a/src/mongo/idl/server_parameter.idl b/src/mongo/idl/server_parameter.idl
new file mode 100644
index 00000000000..2fb39ad0815
--- /dev/null
+++ b/src/mongo/idl/server_parameter.idl
@@ -0,0 +1,49 @@
+# Copyright (C) 2022-present MongoDB, Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the Server Side Public License, version 1,
+# as published by MongoDB, Inc.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# Server Side Public License for more details.
+#
+# You should have received a copy of the Server Side Public License
+# along with this program. If not, see
+# <http://www.mongodb.com/licensing/server-side-public-license>.
+#
+# As a special exception, the copyright holders give permission to link the
+# code of portions of this program with the OpenSSL library under certain
+# conditions as described in each individual source file and distribute
+# linked combinations including the program with the OpenSSL library. You
+# must comply with the Server Side Public License in all respects for
+# all of the code used other than as permitted herein. If you modify file(s)
+# with this exception, you may extend this exception to your version of the
+# file(s), but you are not obligated to do so. If you do not wish to do so,
+# delete this exception statement from your version. If you delete this
+# exception statement from all source files in the program, then also delete
+# it in the license file.
+#
+# IDL constructs useful for all server parameters.
+
+global:
+    cpp_namespace: "mongo"
+
+imports:
+    - "mongo/idl/basic_types.idl"
+
+# Options for the getParameter command. Describes the object "options" when the command is run as 
+# {getParameter: <options>}
+structs:
+  GetParameterOptions:
+    description: 'Optional flags to pass to {getParameter: options, ...}'
+    fields: 
+      showDetails:
+        description: 'Return metadata about the server parameter along with its current value'
+        type: safeBool
+        default: false
+      allParameters:
+        description: 'Return all server parameters, not just the ones specified'
+        type: safeBool
+        default: false