nixos/yggdrasil: change config priority, persistentKeys

Favor the configuration in "configFile" over "config" to allow
"configFile" to override "config" without a system rebuild.

Add a "persistentKeys" option to generate keys and addresses that
persist across service restarts. This is useful for self-configuring
boot media.
This commit is contained in:
Emery Hemingway 2020-05-03 16:00:31 +05:30
parent 067ad3cc94
commit ac97b19a2a
2 changed files with 72 additions and 68 deletions

View file

@ -1,55 +1,17 @@
{ config, lib, pkgs, ... }:
with lib;
let
keysPath = "/var/lib/yggdrasil/keys.json";
cfg = config.services.yggdrasil;
configProvided = (cfg.config != {});
configAsFile = (if configProvided then
toString (pkgs.writeTextFile {
name = "yggdrasil-conf";
text = builtins.toJSON cfg.config;
})
else null);
configFileProvided = (cfg.configFile != null);
generateConfig = (
if configProvided && configFileProvided then
"${pkgs.jq}/bin/jq -s add ${configAsFile} ${cfg.configFile}"
else if configProvided then
"cat ${configAsFile}"
else if configFileProvided then
"cat ${cfg.configFile}"
else
"${cfg.package}/bin/yggdrasil -genconf"
);
configProvided = cfg.config != { };
configFileProvided = cfg.configFile != null;
in {
options = with types; {
services.yggdrasil = {
enable = mkEnableOption "the yggdrasil system service";
configFile = mkOption {
type = nullOr str;
default = null;
example = "/run/keys/yggdrasil.conf";
description = ''
A file which contains JSON configuration for yggdrasil.
You do not have to supply a complete configuration, as
yggdrasil will use default values for anything which is
omitted. If the encryption and signing keys are omitted,
yggdrasil will generate new ones each time the service is
started, resulting in a random IPv6 address on the yggdrasil
network each time.
If both this option and <option>config</option> are
supplied, they will be combined, with values from
<option>config</option> taking precedence.
You can use the command <code>nix-shell -p yggdrasil --run
"yggdrasil -genconf -json"</code> to generate a default
JSON configuration.
'';
};
config = mkOption {
type = attrs;
default = {};
@ -66,16 +28,21 @@ in {
Configuration for yggdrasil, as a Nix attribute set.
Warning: this is stored in the WORLD-READABLE Nix store!
Therefore, it is not appropriate for private keys. If you
do not specify the keys, yggdrasil will generate a new set
each time the service is started, creating a random IPv6
address on the yggdrasil network each time.
Therefore, it is not appropriate for private keys. If you
wish to specify the keys, use <option>configFile</option>.
If you wish to specify the keys, use
<option>configFile</option>. If both
<option>configFile</option> and <option>config</option> are
supplied, they will be combined, with values from
<option>config</option> taking precedence.
If the <option>persistentKeys</option> is enabled then the
keys that are generated during activation will override
those in <option>config</option> or
<option>configFile</option>.
If no keys are specified then ephemeral keys are generated
and the Yggdrasil interface will have a random IPv6 address
each time the service is started, this is the default.
If both <option>configFile</option> and <option>config</option>
are supplied, they will be combined, with values from
<option>configFile</option> taking precedence.
You can use the command <code>nix-shell -p yggdrasil --run
"yggdrasil -genconf"</code> to generate default
@ -83,12 +50,21 @@ in {
'';
};
configFile = mkOption {
type = nullOr path;
default = null;
example = "/run/keys/yggdrasil.conf";
description = ''
A file which contains JSON configuration for yggdrasil.
See the <option>config</option> option for more information.
'';
};
group = mkOption {
type = types.str;
default = "root";
example = "wheel";
description =
"Group to grant acces to the Yggdrasil control socket.";
description = "Group to grant acces to the Yggdrasil control socket.";
};
openMulticastPort = mkOption {
@ -126,37 +102,64 @@ in {
defaultText = "pkgs.yggdrasil";
description = "Yggdrasil package to use.";
};
persistentKeys = mkEnableOption ''
If enabled then keys will be generated once and Yggdrasil
will retain the same IPv6 address when the service is
restarted. Keys are stored at ${keysPath}.
'';
};
};
config = mkIf cfg.enable {
assertions = [
{ assertion = config.networking.enableIPv6;
message = "networking.enableIPv6 must be true for yggdrasil to work";
}
];
config = mkIf cfg.enable (let binYggdrasil = cfg.package + "/bin/yggdrasil";
in {
assertions = [{
assertion = config.networking.enableIPv6;
message = "networking.enableIPv6 must be true for yggdrasil to work";
}];
system.activationScripts.yggdrasil = mkIf cfg.persistentKeys ''
if [ ! -e ${keysPath} ]
then
mkdir -p ${builtins.dirOf keysPath}
${binYggdrasil} -genconf -json \
| ${pkgs.jq}/bin/jq \
'to_entries|map(select(.key|endswith("Key")))|from_entries' \
> ${keysPath}
chmod 600 ${keysPath}
fi
'';
systemd.services.yggdrasil = {
description = "Yggdrasil Network Service";
path = [ cfg.package ] ++ optional (configProvided && configFileProvided) pkgs.jq;
bindsTo = [ "network-online.target" ];
after = [ "network-online.target" ];
wantedBy = [ "multi-user.target" ];
preStart = ''
${generateConfig} | yggdrasil -normaliseconf -useconf > /run/yggdrasil/yggdrasil.conf
'';
preStart =
(if configProvided || configFileProvided || cfg.persistentKeys then
"echo "
+ (lib.optionalString configProvided
"'${builtins.toJSON cfg.config}'")
+ (lib.optionalString configFileProvided "$(cat ${cfg.configFile})")
+ (lib.optionalString cfg.persistentKeys "$(cat ${keysPath})")
+ " | ${pkgs.jq}/bin/jq -s add | ${binYggdrasil} -normaliseconf -useconf"
else
"${binYggdrasil} -genconf") + " > /run/yggdrasil/yggdrasil.conf";
serviceConfig = {
ExecStart = "${cfg.package}/bin/yggdrasil -useconffile /run/yggdrasil/yggdrasil.conf";
ExecStart =
"${binYggdrasil} -useconffile /run/yggdrasil/yggdrasil.conf";
ExecReload = "${pkgs.coreutils}/bin/kill -HUP $MAINPID";
Restart = "always";
Group = cfg.group;
RuntimeDirectory = "yggdrasil";
RuntimeDirectoryMode = "0750";
BindReadOnlyPaths = mkIf configFileProvided
[ "${cfg.configFile}" ];
BindReadOnlyPaths = lib.optional configFileProvided cfg.configFile
++ lib.optional cfg.persistentKeys keysPath;
# TODO: as of yggdrasil 0.3.8 and systemd 243, yggdrasil fails
# to set up the network adapter when DynamicUser is set. See
@ -191,6 +194,6 @@ in {
# Make yggdrasilctl available on the command line.
environment.systemPackages = [ cfg.package ];
};
meta.maintainers = with lib.maintainers; [ gazally ];
});
meta.maintainers = with lib.maintainers; [ gazally ehmry ];
}

View file

@ -85,6 +85,7 @@ in import ./make-test-python.nix ({ pkgs, ...} : {
MulticastInterfaces = [ "eth1" ];
LinkLocalTCPPort = 43210;
};
persistentKeys = true;
};
};
};