From 061c913c366b339fd28b741ca2f56dacb64497f8 Mon Sep 17 00:00:00 2001
From: Izorkin <izorkin@elven.pw>
Date: Sat, 3 Apr 2021 23:00:48 +0300
Subject: [PATCH 1/2] nixos/redis: enable sandbox mode

---
 nixos/modules/services/databases/redis.nix | 26 ++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/nixos/modules/services/databases/redis.nix b/nixos/modules/services/databases/redis.nix
index 3ddc7aad81e..24fe4ab3cc2 100644
--- a/nixos/modules/services/databases/redis.nix
+++ b/nixos/modules/services/databases/redis.nix
@@ -295,6 +295,32 @@ in
         StateDirectoryMode = "0700";
         # Access write directories
         UMask = "0077";
+        # Capabilities
+        CapabilityBoundingSet = "";
+        # Security
+        NoNewPrivileges = true;
+        # Sandboxing
+        ProtectSystem = "strict";
+        ProtectHome = true;
+        PrivateTmp = true;
+        PrivateDevices = true;
+        PrivateUsers = true;
+        ProtectClock = true;
+        ProtectHostname = true;
+        ProtectKernelLogs = true;
+        ProtectKernelModules = true;
+        ProtectKernelTunables = true;
+        ProtectControlGroups = true;
+        RestrictAddressFamilies = [ "AF_UNIX" "AF_INET" "AF_INET6" ];
+        RestrictNamespaces = true;
+        LockPersonality = true;
+        MemoryDenyWriteExecute = true;
+        RestrictRealtime = true;
+        RestrictSUIDSGID = true;
+        PrivateMounts = true;
+        # System Call Filtering
+        SystemCallArchitectures = "native";
+        SystemCallFilter = "~@clock @cpu-emulation @debug @keyring @memlock @module @mount @obsolete @privileged @raw-io @reboot @resources @setuid @swap";
       };
     };
   };

From e075aeb8c0113b3d91c63aa99b22dcb4ce5a0d81 Mon Sep 17 00:00:00 2001
From: Izorkin <izorkin@elven.pw>
Date: Mon, 12 Apr 2021 12:36:28 +0300
Subject: [PATCH 2/2] nixos/redis: add option maxclients

---
 nixos/modules/services/databases/redis.nix | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/nixos/modules/services/databases/redis.nix b/nixos/modules/services/databases/redis.nix
index 24fe4ab3cc2..7ec10c0eb5a 100644
--- a/nixos/modules/services/databases/redis.nix
+++ b/nixos/modules/services/databases/redis.nix
@@ -5,6 +5,8 @@ with lib;
 let
   cfg = config.services.redis;
 
+  ulimitNofile = cfg.maxclients + 32;
+
   mkValueString = value:
     if value == true then "yes"
     else if value == false then "no"
@@ -14,8 +16,8 @@ let
     listsAsDuplicateKeys = true;
     mkKeyValue = generators.mkKeyValueDefault { inherit mkValueString; } " ";
   } cfg.settings);
-in
-{
+
+in {
   imports = [
     (mkRemovedOptionModule [ "services" "redis" "user" ] "The redis module now is hardcoded to the redis user.")
     (mkRemovedOptionModule [ "services" "redis" "dbpath" ] "The redis module now uses /var/lib/redis as data directory.")
@@ -121,6 +123,12 @@ in
         description = "Set the number of databases.";
       };
 
+      maxclients = mkOption {
+        type = types.int;
+        default = 10000;
+        description = "Set the max number of connected clients at the same time.";
+      };
+
       save = mkOption {
         type = with types; listOf (listOf int);
         default = [ [900 1] [300 10] [60 10000] ];
@@ -253,6 +261,7 @@ in
         logfile = cfg.logfile;
         syslog-enabled = cfg.syslog;
         databases = cfg.databases;
+        maxclients = cfg.maxclients;
         save = map (d: "${toString (builtins.elemAt d 0)} ${toString (builtins.elemAt d 1)}") cfg.save;
         dbfilename = "dump.rdb";
         dir = "/var/lib/redis";
@@ -299,6 +308,8 @@ in
         CapabilityBoundingSet = "";
         # Security
         NoNewPrivileges = true;
+        # Process Properties
+        LimitNOFILE = "${toString ulimitNofile}";
         # Sandboxing
         ProtectSystem = "strict";
         ProtectHome = true;