nixosTest reusable test setup via module system #171396
Description
Describe the problem
Test setup isn't reusable. For example, if you want to have a dns server in my network, you have to duplicate configuration from existing dns server tests. Testing should be easy!
This also brings nixosTest closer to NixOps 2. Interop is feasible (as long as user is ok not to access resources directly but via user-declared network-level options).
Implementation
Refactor nixosTest aka makeTest to take a module instead of regular attrset arguments.
Module composition will allow the creation of modules that affect multiple nodes and/or the test script.
Example module for adding and configuring a DNS server:
{ config, lib, options, pkgs, ... }:
{
nodes = {
ns = { nodes, ... }: {
networking.firewall.allowedUDPPorts = [ 53 ];
services.bind.enable = true;
services.bind.extraOptions = "empty-zones-enable no;";
services.bind.zones = [{
name = ".";
master = true;
file = writeText "root.zone" ''
$TTL 3600
. IN SOA ns. ns. ( 1 8 2 4 1 )
. IN NS ns.
${concatMapStringsSep "\n"
(node: "${node.config.networking.hostName}. IN A ${node.config.networking.primaryIPAddress}")
(builtins.attrValues nodes)
}
'';
}];
};
};
# `default` is added to all `nodes.*`, type: deferredModule
default = { config, ... }: {
networking.dhcpcd.enable = false;
environment.etc."resolv.conf".text = ''
nameserver ${nodes.ns.config.networking.primaryIPAddress}
'';
};
# prefixed to testScript, type: lines
testScriptPrelude = ''
def wait_dns():
ns.wait_for_unit("bind.service")
ns.wait_for_open_port(53)
'';
}Example usage:
nixosTest {
imports = [ nixosTestModules.bind ];
nodes.foo = /* ... */;
testScript = ''
start_all();
wait_dns();
# ...
'';
}Other module ideas:
- Set up a mock mail server and adds assertion methods for checking / waiting for mail arrival
- A module that sets up the host sandbox as a binary cache via 9p + local. (might need a tweak in Nix itself, or recursive Nix)
- Clean up
nixosTestimplementation by splitting existing code into modules.
Notify maintainers
Metadata
Please run nix-shell -p nix-info --run "nix-info -m" and paste the result.
[user@system:~]$ nix-shell -p nix-info --run "nix-info -m"
output here