nixpkgs/nixos/modules/services/networking/keepalived/default.nix

324 lines
9.9 KiB
Nix

{ 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 = lib.mdDoc ''
Whether to enable Keepalived.
'';
};
enableScriptSecurity = mkOption {
type = types.bool;
default = false;
description = lib.mdDoc ''
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 = lib.mdDoc ''
Whether to enable the builtin AgentX subagent.
'';
};
socket = mkOption {
type = types.nullOr types.str;
default = null;
description = lib.mdDoc ''
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 = lib.mdDoc ''
Enable SNMP handling of vrrp element of KEEPALIVED MIB.
'';
};
enableChecker = mkOption {
type = types.bool;
default = false;
description = lib.mdDoc ''
Enable SNMP handling of checker element of KEEPALIVED MIB.
'';
};
enableRfc = mkOption {
type = types.bool;
default = false;
description = lib.mdDoc ''
Enable SNMP handling of RFC2787 and RFC6527 VRRP MIBs.
'';
};
enableRfcV2 = mkOption {
type = types.bool;
default = false;
description = lib.mdDoc ''
Enable SNMP handling of RFC2787 VRRP MIB.
'';
};
enableRfcV3 = mkOption {
type = types.bool;
default = false;
description = lib.mdDoc ''
Enable SNMP handling of RFC6527 VRRP MIB.
'';
};
enableTraps = mkOption {
type = types.bool;
default = false;
description = lib.mdDoc ''
Enable SNMP traps.
'';
};
};
vrrpScripts = mkOption {
type = types.attrsOf (types.submodule (import ./vrrp-script-options.nix {
inherit lib;
}));
default = {};
description = lib.mdDoc "Declarative vrrp script config";
};
vrrpInstances = mkOption {
type = types.attrsOf (types.submodule (import ./vrrp-instance-options.nix {
inherit lib;
}));
default = {};
description = lib.mdDoc "Declarative vhost config";
};
extraGlobalDefs = mkOption {
type = types.lines;
default = "";
description = lib.mdDoc ''
Extra lines to be added verbatim to the 'global_defs' block of the
configuration file
'';
};
extraConfig = mkOption {
type = types.lines;
default = "";
description = lib.mdDoc ''
Extra lines to be added verbatim to the configuration file.
'';
};
secretFile = mkOption {
type = types.nullOr types.path;
default = null;
example = "/run/keys/keepalived.env";
description = lib.mdDoc ''
Environment variables from this file will be interpolated into the
final config file using envsubst with this syntax: `$ENVIRONMENT`
or `''${VARIABLE}`.
The file should contain lines formatted as `SECRET_VAR=SECRET_VALUE`.
This is useful to avoid putting secrets into the nix store.
'';
};
};
};
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 = let
finalConfigFile = if cfg.secretFile == null then keepalivedConf else "/run/keepalived/keepalived.conf";
in {
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";
RuntimeDirectory = "keepalived";
EnvironmentFile = lib.optional (cfg.secretFile != null) cfg.secretFile;
ExecStartPre = lib.optional (cfg.secretFile != null)
(pkgs.writeShellScript "keepalived-pre-start" ''
umask 077
${pkgs.envsubst}/bin/envsubst -i "${keepalivedConf}" > ${finalConfigFile}
'');
ExecStart = "${pkgs.keepalived}/sbin/keepalived"
+ " -f ${finalConfigFile}"
+ " -p ${pidFile}"
+ optionalString cfg.snmp.enable " --snmp";
ExecReload = "${pkgs.coreutils}/bin/kill -HUP $MAINPID";
Restart = "always";
RestartSec = "1s";
};
};
};
}