summary refs log tree commit diff
path: root/nixos/modules/services/networking/ucarp.nix
diff options
context:
space:
mode:
Diffstat (limited to 'nixos/modules/services/networking/ucarp.nix')
-rw-r--r--nixos/modules/services/networking/ucarp.nix183
1 files changed, 183 insertions, 0 deletions
diff --git a/nixos/modules/services/networking/ucarp.nix b/nixos/modules/services/networking/ucarp.nix
new file mode 100644
index 00000000000..189e4f99cef
--- /dev/null
+++ b/nixos/modules/services/networking/ucarp.nix
@@ -0,0 +1,183 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.networking.ucarp;
+
+  ucarpExec = concatStringsSep " " (
+    [
+      "${cfg.package}/bin/ucarp"
+      "--interface=${cfg.interface}"
+      "--srcip=${cfg.srcIp}"
+      "--vhid=${toString cfg.vhId}"
+      "--passfile=${cfg.passwordFile}"
+      "--addr=${cfg.addr}"
+      "--advbase=${toString cfg.advBase}"
+      "--advskew=${toString cfg.advSkew}"
+      "--upscript=${cfg.upscript}"
+      "--downscript=${cfg.downscript}"
+      "--deadratio=${toString cfg.deadratio}"
+    ]
+    ++ (optional cfg.preempt "--preempt")
+    ++ (optional cfg.neutral "--neutral")
+    ++ (optional cfg.shutdown "--shutdown")
+    ++ (optional cfg.ignoreIfState "--ignoreifstate")
+    ++ (optional cfg.noMcast "--nomcast")
+    ++ (optional (cfg.extraParam != null) "--xparam=${cfg.extraParam}")
+  );
+in {
+  options.networking.ucarp = {
+    enable = mkEnableOption "ucarp, userspace implementation of CARP";
+
+    interface = mkOption {
+      type = types.str;
+      description = "Network interface to bind to.";
+      example = "eth0";
+    };
+
+    srcIp = mkOption {
+      type = types.str;
+      description = "Source (real) IP address of this host.";
+    };
+
+    vhId = mkOption {
+      type = types.ints.between 1 255;
+      description = "Virtual IP identifier shared between CARP hosts.";
+      example = 1;
+    };
+
+    passwordFile = mkOption {
+      type = types.str;
+      description = "File containing shared password between CARP hosts.";
+      example = "/run/keys/ucarp-password";
+    };
+
+    preempt = mkOption {
+      type = types.bool;
+      description = ''
+        Enable preemptive failover.
+        Thus, this host becomes the CARP master as soon as possible.
+      '';
+      default = false;
+    };
+
+    neutral = mkOption {
+      type = types.bool;
+      description = "Do not run downscript at start if the host is the backup.";
+      default = false;
+    };
+
+    addr = mkOption {
+      type = types.str;
+      description = "Virtual shared IP address.";
+    };
+
+    advBase = mkOption {
+      type = types.ints.unsigned;
+      description = "Advertisement frequency in seconds.";
+      default = 1;
+    };
+
+    advSkew = mkOption {
+      type = types.ints.unsigned;
+      description = "Advertisement skew in seconds.";
+      default = 0;
+    };
+
+    upscript = mkOption {
+      type = types.path;
+      description = ''
+        Command to run after become master, the interface name, virtual address
+        and optional extra parameters are passed as arguments.
+      '';
+      example = literalExpression ''
+        pkgs.writeScript "upscript" '''
+          #!/bin/sh
+          ''${pkgs.iproute2}/bin/ip addr add "$2"/24 dev "$1"
+        ''';
+      '';
+    };
+
+    downscript = mkOption {
+      type = types.path;
+      description = ''
+        Command to run after become backup, the interface name, virtual address
+        and optional extra parameters are passed as arguments.
+      '';
+      example = literalExpression ''
+        pkgs.writeScript "downscript" '''
+          #!/bin/sh
+          ''${pkgs.iproute2}/bin/ip addr del "$2"/24 dev "$1"
+        ''';
+      '';
+    };
+
+    deadratio = mkOption {
+      type = types.ints.unsigned;
+      description = "Ratio to consider a host as dead.";
+      default = 3;
+    };
+
+    shutdown = mkOption {
+      type = types.bool;
+      description = "Call downscript at exit.";
+      default = false;
+    };
+
+    ignoreIfState = mkOption {
+      type = types.bool;
+      description = "Ignore interface state, e.g., down or no carrier.";
+      default = false;
+    };
+
+    noMcast = mkOption {
+      type = types.bool;
+      description = "Use broadcast instead of multicast advertisements.";
+      default = false;
+    };
+
+    extraParam = mkOption {
+      type = types.nullOr types.str;
+      description = "Extra parameter to pass to the up/down scripts.";
+      default = null;
+    };
+
+    package = mkOption {
+      type = types.package;
+      description = ''
+        Package that should be used for ucarp.
+
+        Please note that the default package, pkgs.ucarp, has not received any
+        upstream updates for a long time and can be considered as unmaintained.
+      '';
+      default = pkgs.ucarp;
+      defaultText = literalExpression "pkgs.ucarp";
+    };
+  };
+
+  config = mkIf cfg.enable {
+    systemd.services.ucarp = {
+      description = "ucarp, userspace implementation of CARP";
+
+      wantedBy = [ "multi-user.target" ];
+      after = [ "network.target" ];
+
+      serviceConfig = {
+        Type = "exec";
+        ExecStart = ucarpExec;
+
+        ProtectSystem = "strict";
+        ProtectHome = true;
+        PrivateTmp = true;
+        ProtectClock = true;
+        ProtectKernelModules = true;
+        ProtectControlGroups = true;
+        MemoryDenyWriteExecute = true;
+        RestrictRealtime = true;
+      };
+    };
+  };
+
+  meta.maintainers = with lib.maintainers; [ oxzi ];
+}