1 files changed, 303 insertions, 0 deletions
diff --git a/nixos/modules/services/networking/keepalived/default.nix b/nixos/modules/services/networking/keepalived/default.nix
new file mode 100644
index 00000000000..c9ac2ee2599
--- /dev/null
+++ b/nixos/modules/services/networking/keepalived/default.nix
@@ -0,0 +1,303 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  cfg = config.services.keepalived;
+
+  keepalivedConf = pkgs.writeText "keepalived.conf" ''
+    global_defs {
+      ${optionalString cfg.enableScriptSecurity "enable_script_security"}
+      ${snmpGlobalDefs}
+      ${cfg.extraGlobalDefs}
+    }
+
+    ${vrrpScriptStr}
+    ${vrrpInstancesStr}
+    ${cfg.extraConfig}
+  '';
+
+  snmpGlobalDefs = with cfg.snmp; optionalString enable (
+    optionalString (socket != null) "snmp_socket ${socket}\n"
+    + optionalString enableKeepalived "enable_snmp_keepalived\n"
+    + optionalString enableChecker "enable_snmp_checker\n"
+    + optionalString enableRfc "enable_snmp_rfc\n"
+    + optionalString enableRfcV2 "enable_snmp_rfcv2\n"
+    + optionalString enableRfcV3 "enable_snmp_rfcv3\n"
+    + optionalString enableTraps "enable_traps"
+  );
+
+  vrrpScriptStr = concatStringsSep "\n" (map (s:
+    ''
+      vrrp_script ${s.name} {
+        script "${s.script}"
+        interval ${toString s.interval}
+        fall ${toString s.fall}
+        rise ${toString s.rise}
+        timeout ${toString s.timeout}
+        weight ${toString s.weight}
+        user ${s.user} ${optionalString (s.group != null) s.group}
+
+        ${s.extraConfig}
+      }
+    ''
+  ) vrrpScripts);
+
+  vrrpInstancesStr = concatStringsSep "\n" (map (i:
+    ''
+      vrrp_instance ${i.name} {
+        interface ${i.interface}
+        state ${i.state}
+        virtual_router_id ${toString i.virtualRouterId}
+        priority ${toString i.priority}
+        ${optionalString i.noPreempt "nopreempt"}
+
+        ${optionalString i.useVmac (
+          "use_vmac" + optionalString (i.vmacInterface != null) " ${i.vmacInterface}"
+        )}
+        ${optionalString i.vmacXmitBase "vmac_xmit_base"}
+
+        ${optionalString (i.unicastSrcIp != null) "unicast_src_ip ${i.unicastSrcIp}"}
+        unicast_peer {
+          ${concatStringsSep "\n" i.unicastPeers}
+        }
+
+        virtual_ipaddress {
+          ${concatMapStringsSep "\n" virtualIpLine i.virtualIps}
+        }
+
+        ${optionalString (builtins.length i.trackScripts > 0) ''
+          track_script {
+            ${concatStringsSep "\n" i.trackScripts}
+          }
+        ''}
+
+        ${optionalString (builtins.length i.trackInterfaces > 0) ''
+          track_interface {
+            ${concatStringsSep "\n" i.trackInterfaces}
+          }
+        ''}
+
+        ${i.extraConfig}
+      }
+    ''
+  ) vrrpInstances);
+
+  virtualIpLine = (ip:
+    ip.addr
+    + optionalString (notNullOrEmpty ip.brd) " brd ${ip.brd}"
+    + optionalString (notNullOrEmpty ip.dev) " dev ${ip.dev}"
+    + optionalString (notNullOrEmpty ip.scope) " scope ${ip.scope}"
+    + optionalString (notNullOrEmpty ip.label) " label ${ip.label}"
+  );
+
+  notNullOrEmpty = s: !(s == null || s == "");
+
+  vrrpScripts = mapAttrsToList (name: config:
+    {
+      inherit name;
+    } // config
+  ) cfg.vrrpScripts;
+
+  vrrpInstances = mapAttrsToList (iName: iConfig:
+    {
+      name = iName;
+    } // iConfig
+  ) cfg.vrrpInstances;
+
+  vrrpInstanceAssertions = i: [
+    { assertion = i.interface != "";
+      message = "services.keepalived.vrrpInstances.${i.name}.interface option cannot be empty.";
+    }
+    { assertion = i.virtualRouterId >= 0 && i.virtualRouterId <= 255;
+      message = "services.keepalived.vrrpInstances.${i.name}.virtualRouterId must be an integer between 0..255.";
+    }
+    { assertion = i.priority >= 0 && i.priority <= 255;
+      message = "services.keepalived.vrrpInstances.${i.name}.priority must be an integer between 0..255.";
+    }
+    { assertion = i.vmacInterface == null || i.useVmac;
+      message = "services.keepalived.vrrpInstances.${i.name}.vmacInterface has no effect when services.keepalived.vrrpInstances.${i.name}.useVmac is not set.";
+    }
+    { assertion = !i.vmacXmitBase || i.useVmac;
+      message = "services.keepalived.vrrpInstances.${i.name}.vmacXmitBase has no effect when services.keepalived.vrrpInstances.${i.name}.useVmac is not set.";
+    }
+  ] ++ flatten (map (virtualIpAssertions i.name) i.virtualIps)
+    ++ flatten (map (vrrpScriptAssertion i.name) i.trackScripts);
+
+  virtualIpAssertions = vrrpName: ip: [
+    { assertion = ip.addr != "";
+      message = "The 'addr' option for an services.keepalived.vrrpInstances.${vrrpName}.virtualIps entry cannot be empty.";
+    }
+  ];
+
+  vrrpScriptAssertion = vrrpName: scriptName: {
+    assertion = builtins.hasAttr scriptName cfg.vrrpScripts;
+    message = "services.keepalived.vrrpInstances.${vrrpName} trackscript ${scriptName} is not defined in services.keepalived.vrrpScripts.";
+  };
+
+  pidFile = "/run/keepalived.pid";
+
+in
+{
+
+  options = {
+    services.keepalived = {
+
+      enable = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Whether to enable Keepalived.
+        '';
+      };
+
+      enableScriptSecurity = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Don't run scripts configured to be run as root if any part of the path is writable by a non-root user.
+        '';
+      };
+
+      snmp = {
+
+        enable = mkOption {
+          type = types.bool;
+          default = false;
+          description = ''
+            Whether to enable the builtin AgentX subagent.
+          '';
+        };
+
+        socket = mkOption {
+          type = types.nullOr types.str;
+          default = null;
+          description = ''
+            Socket to use for connecting to SNMP master agent. If this value is
+            set to null, keepalived's default will be used, which is
+            unix:/var/agentx/master, unless using a network namespace, when the
+            default is udp:localhost:705.
+          '';
+        };
+
+        enableKeepalived = mkOption {
+          type = types.bool;
+          default = false;
+          description = ''
+            Enable SNMP handling of vrrp element of KEEPALIVED MIB.
+          '';
+        };
+
+        enableChecker = mkOption {
+          type = types.bool;
+          default = false;
+          description = ''
+            Enable SNMP handling of checker element of KEEPALIVED MIB.
+          '';
+        };
+
+        enableRfc = mkOption {
+          type = types.bool;
+          default = false;
+          description = ''
+            Enable SNMP handling of RFC2787 and RFC6527 VRRP MIBs.
+          '';
+        };
+
+        enableRfcV2 = mkOption {
+          type = types.bool;
+          default = false;
+          description = ''
+            Enable SNMP handling of RFC2787 VRRP MIB.
+          '';
+        };
+
+        enableRfcV3 = mkOption {
+          type = types.bool;
+          default = false;
+          description = ''
+            Enable SNMP handling of RFC6527 VRRP MIB.
+          '';
+        };
+
+        enableTraps = mkOption {
+          type = types.bool;
+          default = false;
+          description = ''
+            Enable SNMP traps.
+          '';
+        };
+
+      };
+
+      vrrpScripts = mkOption {
+        type = types.attrsOf (types.submodule (import ./vrrp-script-options.nix {
+          inherit lib;
+        }));
+        default = {};
+        description = "Declarative vrrp script config";
+      };
+
+      vrrpInstances = mkOption {
+        type = types.attrsOf (types.submodule (import ./vrrp-instance-options.nix {
+          inherit lib;
+        }));
+        default = {};
+        description = "Declarative vhost config";
+      };
+
+      extraGlobalDefs = mkOption {
+        type = types.lines;
+        default = "";
+        description = ''
+          Extra lines to be added verbatim to the 'global_defs' block of the
+          configuration file
+        '';
+      };
+
+      extraConfig = mkOption {
+        type = types.lines;
+        default = "";
+        description = ''
+          Extra lines to be added verbatim to the configuration file.
+        '';
+      };
+
+    };
+  };
+
+  config = mkIf cfg.enable {
+
+    assertions = flatten (map vrrpInstanceAssertions vrrpInstances);
+
+    systemd.timers.keepalived-boot-delay = {
+      description = "Keepalive Daemon delay to avoid instant transition to MASTER state";
+      after = [ "network.target" "network-online.target" "syslog.target" ];
+      requires = [ "network-online.target" ];
+      wantedBy = [ "multi-user.target" ];
+      timerConfig = {
+        OnActiveSec = "5s";
+        Unit = "keepalived.service";
+      };
+    };
+
+    systemd.services.keepalived = {
+      description = "Keepalive Daemon (LVS and VRRP)";
+      after = [ "network.target" "network-online.target" "syslog.target" ];
+      wants = [ "network-online.target" ];
+      serviceConfig = {
+        Type = "forking";
+        PIDFile = pidFile;
+        KillMode = "process";
+        ExecStart = "${pkgs.keepalived}/sbin/keepalived"
+          + " -f ${keepalivedConf}"
+          + " -p ${pidFile}"
+          + optionalString cfg.snmp.enable " --snmp";
+        ExecReload = "${pkgs.coreutils}/bin/kill -HUP $MAINPID";
+        Restart = "always";
+        RestartSec = "1s";
+      };
+    };
+  };
+}