nixpkgs/nixos/tests/containers-names.nix
Patryk Wychowaniec 336ef2de99
nixos/containers: allow containers with long names to create private networks
Launching a container with a private network requires creating a
dedicated networking interface for it; name of that interface is derived
from the container name itself - e.g. a container named `foo` gets
attached to an interface named `ve-foo`.

An interface name can span up to IFNAMSIZ characters, which means that a
container name must contain at most IFNAMSIZ - 3 - 1 = 11 characters;
it's a limit that we validate using a build-time assertion.

This limit has been upgraded with Linux 5.8, as it allows for an
interface to contain a so-called altname, which can be much longer,
while remaining treated as a first-class citizen.

Since altnames have been supported natively by systemd for a while now,
due diligence on our side ends with dropping the name-assertion on newer
kernels.

This commit closes #38509.

systemd/systemd#14467
systemd/systemd#17220
https://lwn.net/Articles/794289/
2021-02-26 17:48:49 +01:00

37 lines
1.1 KiB
Nix

import ./make-test-python.nix ({ pkgs, lib, ... }: {
name = "containers-names";
meta = {
maintainers = with lib.maintainers; [ patryk27 ];
};
machine = { ... }: {
# We're using the newest kernel, so that we can test containers with long names.
# Please see https://github.com/NixOS/nixpkgs/issues/38509 for details.
boot.kernelPackages = pkgs.linuxPackages_latest;
containers = let
container = subnet: {
autoStart = true;
privateNetwork = true;
hostAddress = "192.168.${subnet}.1";
localAddress = "192.168.${subnet}.2";
config = { };
};
in {
first = container "1";
second = container "2";
really-long-name = container "3";
really-long-long-name-2 = container "4";
};
};
testScript = ''
machine.wait_for_unit("default.target")
machine.succeed("ip link show | grep ve-first")
machine.succeed("ip link show | grep ve-second")
machine.succeed("ip link show | grep ve-really-lFYWO")
machine.succeed("ip link show | grep ve-really-l3QgY")
'';
})