nixpkgs/nixos/tests/systemd-networkd.nix
Félix Baylac-Jacqué f63c842f1e
nixosTests.systemd-networkd: fix test flakiness
The original idea for this test was, on top of providing a networkd
test, to provide newcomers with a sample configuration they could use
to get started with networkd.

That's precisely why we were doing this systemd tmpfile dance in the
first place. It was a convenient way to create a runtime file with a
specific mode and owner.

Sadly, this tmpfile rule made the test flaky. There's a race condition
between the wireguard interface configured by systemd-networkd and
systemd-tmpfiles-setup.

Sometimes, networkd is going to try loading the wireguard private key
file *before* the said file gets created by systemd-tmpfiles.

A perfect solution here would be to create a "After" dependency
between wg0.netdev and systemd-tmpfiles-setup.service. Sadly, it is
currently impossible to create such a dependency between a
networkd-specific unit and a service.

We're removing this tmp file in favor of pointing networkd directly to
the Nix store. This is clearly something that shouldn't be done in the
real world for a private file: the store is world-readable. However,
this is the only way I found to fix this test flakiness for now.
2020-08-30 21:03:27 +02:00

115 lines
4.3 KiB
Nix

let generateNodeConf = { lib, pkgs, config, privk, pubk, peerId, nodeId, ...}: {
imports = [ common/user-account.nix ];
systemd.services.systemd-networkd.environment.SYSTEMD_LOG_LEVEL = "debug";
networking.useNetworkd = true;
networking.useDHCP = false;
networking.firewall.enable = false;
virtualisation.vlans = [ 1 ];
environment.systemPackages = with pkgs; [ wireguard-tools ];
boot.extraModulePackages = [ config.boot.kernelPackages.wireguard ];
systemd.network = {
enable = true;
netdevs = {
"90-wg0" = {
netdevConfig = { Kind = "wireguard"; Name = "wg0"; };
wireguardConfig = {
# NOTE: we're storing the wireguard private key in the
# store for this test. Do not do this in the real
# world. Keep in mind the nix store is
# world-readable.
PrivateKeyFile = pkgs.writeText "wg0-priv" privk;
ListenPort = 51820;
FirewallMark = 42;
};
wireguardPeers = [ {wireguardPeerConfig={
Endpoint = "192.168.1.${peerId}:51820";
PublicKey = pubk;
PresharedKeyFile = pkgs.writeText "psk.key" "yTL3sCOL33Wzi6yCnf9uZQl/Z8laSE+zwpqOHC4HhFU=";
AllowedIPs = [ "10.0.0.${peerId}/32" ];
PersistentKeepalive = 15;
};}];
};
};
networks = {
"99-nope" = {
matchConfig.Name = "eth*";
linkConfig.Unmanaged = true;
};
"90-wg0" = {
matchConfig = { Name = "wg0"; };
address = [ "10.0.0.${nodeId}/32" ];
routes = [
{ routeConfig = { Gateway = "10.0.0.${nodeId}"; Destination = "10.0.0.0/24"; }; }
];
};
"30-eth1" = {
matchConfig = { Name = "eth1"; };
address = [
"192.168.1.${nodeId}/24"
"fe80::${nodeId}/64"
];
routingPolicyRules = [
{ routingPolicyRuleConfig = { Table = 10; IncomingInterface = "eth1"; Family = "both"; };}
{ routingPolicyRuleConfig = { Table = 20; OutgoingInterface = "eth1"; };}
{ routingPolicyRuleConfig = { Table = 30; From = "192.168.1.1"; To = "192.168.1.2"; SourcePort = 666 ; DestinationPort = 667; };}
{ routingPolicyRuleConfig = { Table = 40; IPProtocol = "tcp"; InvertRule = true; };}
{ routingPolicyRuleConfig = { Table = 50; IncomingInterface = "eth1"; Family = "ipv4"; };}
];
};
};
};
};
in import ./make-test-python.nix ({pkgs, ... }: {
name = "networkd";
meta = with pkgs.stdenv.lib.maintainers; {
maintainers = [ ninjatrappeur ];
};
nodes = {
node1 = { pkgs, ... }@attrs:
let localConf = {
privk = "GDiXWlMQKb379XthwX0haAbK6hTdjblllpjGX0heP00=";
pubk = "iRxpqj42nnY0Qz8MAQbSm7bXxXP5hkPqWYIULmvW+EE=";
nodeId = "1";
peerId = "2";
};
in generateNodeConf (attrs // localConf);
node2 = { pkgs, ... }@attrs:
let localConf = {
privk = "eHxSI2jwX/P4AOI0r8YppPw0+4NZnjOxfbS5mt06K2k=";
pubk = "27s0OvaBBdHoJYkH9osZpjpgSOVNw+RaKfboT/Sfq0g=";
nodeId = "2";
peerId = "1";
};
in generateNodeConf (attrs // localConf);
};
testScript = ''
start_all()
node1.wait_for_unit("systemd-networkd-wait-online.service")
node2.wait_for_unit("systemd-networkd-wait-online.service")
# ================================
# Wireguard
# ================================
node1.succeed("ping -c 5 10.0.0.2")
node2.succeed("ping -c 5 10.0.0.1")
# Is the fwmark set?
node2.succeed("wg | grep -q 42")
# ================================
# Routing Policies
# ================================
# Testing all the routingPolicyRuleConfig members:
# Table + IncomingInterface
node1.succeed("sudo ip rule | grep 'from all iif eth1 lookup 10'")
# OutgoingInterface
node1.succeed("sudo ip rule | grep 'from all oif eth1 lookup 20'")
# From + To + SourcePort + DestinationPort
node1.succeed(
"sudo ip rule | grep 'from 192.168.1.1 to 192.168.1.2 sport 666 dport 667 lookup 30'"
)
# IPProtocol + InvertRule
node1.succeed("sudo ip rule | grep 'not from all ipproto tcp lookup 40'")
'';
})