SERVER-36807 Add --setShellParameter to shell

3 files changed, 64 insertions, 0 deletions

diff --git a/jstests/noPassthrough/setshellparameter.js b/jstests/noPassthrough/setshellparameter.js
new file mode 100644
index 00000000000..9fd17abb605
--- /dev/null
+++ b/jstests/noPassthrough/setshellparameter.js
@@ -0,0 +1,22 @@
+// Test --setShellParameter CLI switch.
+
+(function() {
+    'use strict';
+
+    function test(ssp, succeed) {
+        const result =
+            runMongoProgram('./mongo', '--setShellParameter', ssp, '--nodb', '--eval', ';');
+        assert.eq(0 == result,
+                  succeed,
+                  '--setShellParameter ' + ssp + 'worked/didn\'t-work unexpectedly');
+    }
+
+    // Whitelisted
+    test('disabledSecureAllocatorDomains=foo', true);
+
+    // Not whitelisted
+    test('enableTestCommands=1', false);
+
+    // Unknown
+    test('theAnswerToTheQuestionOfLifeTheUniverseAndEverything=42', false);
+})();
diff --git a/src/mongo/SConscript b/src/mongo/SConscript
index 9a53426ed70..e262fe78f4a 100644
--- a/src/mongo/SConscript
+++ b/src/mongo/SConscript
@@ -496,6 +496,9 @@ if not has_option('noshell') and usemozjs:
                     'executor/network_interface_thread_pool',
                     'executor/network_interface_factory'
                 ],
+                LIBDEPS_PRIVATE=[
+                    'db/server_parameters',
+                ],
                 # Because `::environ` is resolved in `/usr/lib/crt1.o` on FreeBSD, this library
                 # needs to be marked `incomplete` on FreeBSD.
                 LIBDEPS_TAGS=[] if not env.TargetOSIs('freebsd') else [
diff --git a/src/mongo/shell/shell_options.cpp b/src/mongo/shell/shell_options.cpp
index 0845fba5b54..71cf4ceb147 100644
--- a/src/mongo/shell/shell_options.cpp
+++ b/src/mongo/shell/shell_options.cpp
@@ -42,6 +42,7 @@
 #include "mongo/config.h"
 #include "mongo/db/auth/sasl_command_constants.h"
 #include "mongo/db/server_options.h"
+#include "mongo/db/server_parameters.h"
 #include "mongo/rpc/protocol.h"
 #include "mongo/shell/shell_utils.h"
 #include "mongo/transport/message_compressor_registry.h"
@@ -60,6 +61,11 @@ using std::vector;
 
 ShellGlobalParams shellGlobalParams;
 
+// SERVER-36807: Limit --setShellParameter to SetParameters we know we want to expose.
+const std::set<std::string> kSetShellParameterWhitelist = {
+    "disabledSecureAllocatorDomains",
+};
+
 Status addMongoShellOptions(moe::OptionSection* options) {
     options->addOptionChaining(
         "shell", "shell", moe::Switch, "run the shell after executing files");
@@ -227,6 +233,14 @@ Status addMongoShellOptions(moe::OptionSection* options) {
     options->addOptionChaining(
         "jsHeapLimitMB", "jsHeapLimitMB", moe::Int, "set the js scope's heap size limit");
 
+    options
+        ->addOptionChaining("setShellParameter",
+                            "setShellParameter",
+                            moe::StringMap,
+                            "Set a configurable parameter")
+        .composing()
+        .hidden();
+
     return Status::OK();
 }
 
@@ -466,6 +480,31 @@ Status storeMongoShellOptions(const moe::Environment& params,
     if (!ret.isOK())
         return ret;
 
+    if (params.count("setShellParameter")) {
+        auto ssp = params["setShellParameter"].as<std::map<std::string, std::string>>();
+        auto map = ServerParameterSet::getGlobal()->getMap();
+        for (auto it : ssp) {
+            const auto& name = it.first;
+            auto paramIt = map.find(name);
+            if (paramIt == map.end() || !kSetShellParameterWhitelist.count(name)) {
+                return {ErrorCodes::BadValue,
+                        str::stream() << "Unknown --setShellParameter '" << name << "'"};
+            }
+            auto* param = paramIt->second;
+            if (!param->allowedToChangeAtStartup()) {
+                return {ErrorCodes::BadValue,
+                        str::stream() << "Cannot use --setShellParameter to set '" << name
+                                      << "' at startup"};
+            }
+            auto status = param->setFromString(it.second);
+            if (!status.isOK()) {
+                return {ErrorCodes::BadValue,
+                        str::stream() << "Bad value for parameter '" << name << "': "
+                                      << status.reason()};
+            }
+        }
+    }
+
     return Status::OK();
 }