home/ssh: enable control master sockets

home/programs/ssh/default.nix

@@ -1,4 +1,8 @@
-{ config, ... }:
+{ config, pkgs, ... }:
+let
+  runtimeDir = "/run/user/${toString config.home.uid}";
+  controlMastersDir = "${runtimeDir}/ssh-controlmasters";
+in
 {
   imports = [
     ./home.nix
@@ -16,5 +20,22 @@
       config.sops.secrets."ssh/secret-config".path
       "mutable_config"
     ];
+
+    controlMaster = "auto";
+    controlPersist = "10m";
+    controlPath = "${controlMastersDir}/%r@%h:%p";
+  };
+
+  systemd.user.services."ssh-create-controlmasters-dir" = {
+    Install.WantedBy = [ "default.target" ];
+    Unit = {
+      Description = "Create directory to store SSH control master sockets";
+      ConditionPathExists = "!${controlMastersDir}";
+    };
+    Service = {
+      Type = "oneshot";
+      ExecStart = "${pkgs.coreutils}/bin/mkdir ${controlMastersDir}";
+      Restart = "on-abort";
+    };
   };
 }