nixpkgs/nixos/modules/services/cluster/k3s/default.nix

102 lines
2.8 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.services.k3s;
in
{
# interface
options.services.k3s = {
enable = mkEnableOption "k3s";
package = mkOption {
type = types.package;
default = pkgs.k3s;
defaultText = "pkgs.k3s";
example = literalExample "pkgs.k3s";
description = "Package that should be used for k3s";
};
role = mkOption {
description = ''
Whether k3s should run as a server or agent.
Note that the server, by default, also runs as an agent.
'';
default = "server";
type = types.enum [ "server" "agent" ];
};
serverAddr = mkOption {
type = types.str;
description = "The k3s server to connect to. This option only makes sense for an agent.";
example = "https://10.0.0.10:6443";
default = "";
};
token = mkOption {
type = types.str;
description = "The k3s token to use when connecting to the server. This option only makes sense for an agent.";
default = "";
};
docker = mkOption {
type = types.bool;
default = false;
description = "Use docker to run containers rather than the built-in containerd.";
};
extraFlags = mkOption {
description = "Extra flags to pass to the k3s command.";
default = "";
example = "--no-deploy traefik --cluster-cidr 10.24.0.0/16";
};
disableAgent = mkOption {
type = types.bool;
default = false;
description = "Only run the server. This option only makes sense for a server.";
};
};
# implementation
config = mkIf cfg.enable {
assertions = [
{
assertion = cfg.role == "agent" -> cfg.serverAddr != "";
message = "serverAddr should be set if role is 'agent'";
}
{
assertion = cfg.role == "agent" -> cfg.token != "";
message = "token should be set if role is 'agent'";
}
];
virtualisation.docker = mkIf cfg.docker {
enable = mkDefault true;
};
systemd.services.k3s = {
description = "k3s service";
after = mkIf cfg.docker [ "docker.service" ];
wantedBy = [ "multi-user.target" ];
serviceConfig = {
# See: https://github.com/rancher/k3s/blob/dddbd16305284ae4bd14c0aade892412310d7edc/install.sh#L197
Type = if cfg.role == "agent" then "exec" else "notify";
KillMode = "process";
Delegate = "yes";
Restart = "always";
RestartSec = "5s";
ExecStart = concatStringsSep " \\\n " (
[
"${cfg.package}/bin/k3s ${cfg.role}"
] ++ (optional cfg.docker "--docker")
++ (optional cfg.disableAgent "--disable-agent")
++ (optional (cfg.role == "agent") "--server ${cfg.serverAddr} --token ${cfg.token}")
++ [ cfg.extraFlags ]
);
};
};
};
}