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tailscale/tstest/integration/vms/nixos_test.go

217 lines
6.6 KiB
Go

// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build linux
package vms
import (
"flag"
"fmt"
"os"
"os/exec"
"path/filepath"
"strings"
"testing"
"text/template"
"tailscale.com/tstest/integration"
"tailscale.com/types/logger"
)
var (
verboseNixOutput = flag.Bool("verbose-nix-output", false, "if set, use verbose nix output (lots of noise)")
)
/*
NOTE(Xe): Okay, so, at a high level testing NixOS is a lot different than
other distros due to NixOS' determinism. Normally NixOS wants packages to
be defined in either an overlay, a custom packageOverrides or even
yolo-inline as a part of the system configuration. This is going to have
us take a different approach compared to other distributions. The overall
plan here is as following:
1. make the binaries as normal
2. template in their paths as raw strings to the nixos system module
3. run `nixos-generators -f qcow -o $CACHE_DIR/tailscale/nixos/version -c generated-config.nix`
4. pass that to the steps that make the virtual machine
It doesn't really make sense for us to use a premade virtual machine image
for this as that will make it harder to deterministically create the image.
*/
const nixosConfigTemplate = `
# NOTE(Xe): This template is going to be heavily commented.
# All NixOS modules are functions. Here is the function prelude for this NixOS
# module that defines the system. It is a function that takes in an attribute
# set (effectively a map[string]nix.Value) and destructures it to some variables:
{
# other NixOS settings as defined in other modules
config,
# nixpkgs, which is basically the standard library of NixOS
pkgs,
# the path to some system-scoped NixOS modules that aren't imported by default
modulesPath,
# the rest of the arguments don't matter
...
}:
# Nix's syntax was inspired by Haskell and other functional languages, so the
# let .. in pattern is used to create scoped variables:
let
# Define the package (derivation) for Tailscale based on the binaries we
# just built for this test:
testTailscale = pkgs.stdenv.mkDerivation {
# The name of the package. This usually includes a version however it
# doesn't matter here.
name = "tailscale-test";
# The path on disk to the "source code" of the package, in this case it is
# the path to the binaries that are built. This needs to be the raw
# unquoted slash-separated path, not a string contaning the path because Nix
# has a special path type.
src = {{.BinPath}};
# We only need to worry about the install phase because we've already
# built the binaries.
phases = "installPhase";
# We need to wrap tailscaled such that it has iptables in its $PATH.
nativeBuildInputs = [ pkgs.makeWrapper ];
# The install instructions for this package ('' ''defines a multi-line string).
# The with statement lets us bring in values into scope as if they were
# defined in the current scope.
installPhase = with pkgs; ''
# This is bash.
# Make the output folders for the package (systemd unit and binary folders).
mkdir -p $out/bin
# Install tailscale{,d}
cp $src/tailscale $out/bin/tailscale
cp $src/tailscaled $out/bin/tailscaled
# Wrap tailscaled with the ip and iptables commands.
wrapProgram $out/bin/tailscaled --prefix PATH : ${
lib.makeBinPath [ iproute iptables ]
}
# Install systemd unit.
cp $src/systemd/tailscaled.service .
sed -i -e "s#/usr/sbin#$out/bin#" -e "/^EnvironmentFile/d" ./tailscaled.service
install -D -m0444 -t $out/lib/systemd/system ./tailscaled.service
'';
};
in {
# This is a QEMU VM. This module has a lot of common qemu VM settings so you
# don't have to set them manually.
imports = [ (modulesPath + "/profiles/qemu-guest.nix") ];
# We need virtio support to boot.
boot.initrd.availableKernelModules =
[ "ata_piix" "uhci_hcd" "virtio_pci" "sr_mod" "virtio_blk" ];
boot.initrd.kernelModules = [ ];
boot.kernelModules = [ ];
boot.extraModulePackages = [ ];
# Curl is needed for one of the steps in cloud-final
systemd.services.cloud-final.path = [ pkgs.curl ];
# yolo, this vm can sudo freely.
security.sudo.wheelNeedsPassword = false;
# Enable cloud-init so we can set VM hostnames and the like the same as other
# distros. This will also take care of SSH keys. It's pretty handy.
services.cloud-init = {
enable = true;
ext4.enable = true;
};
# We want sshd running.
services.openssh.enable = true;
# Tailscale settings:
services.tailscale = {
# We want Tailscale to start at boot.
enable = true;
# Use the Tailscale package we just assembled.
package = testTailscale;
};
}`
func copyUnit(t *testing.T, bins *integration.Binaries) {
t.Helper()
data, err := os.ReadFile("../../../cmd/tailscaled/tailscaled.service")
if err != nil {
t.Fatal(err)
}
os.MkdirAll(filepath.Join(bins.Dir, "systemd"), 0755)
err = os.WriteFile(filepath.Join(bins.Dir, "systemd", "tailscaled.service"), data, 0666)
if err != nil {
t.Fatal(err)
}
}
func makeNixOSImage(t *testing.T, d Distro, cdir string, bins *integration.Binaries) string {
copyUnit(t, bins)
dir := t.TempDir()
fname := filepath.Join(dir, d.name+".nix")
fout, err := os.Create(fname)
if err != nil {
t.Fatal(err)
}
tmpl := template.Must(template.New("base.nix").Parse(nixosConfigTemplate))
err = tmpl.Execute(fout, struct{ BinPath string }{BinPath: bins.Dir})
if err != nil {
t.Fatal(err)
}
err = fout.Close()
if err != nil {
t.Fatal(err)
}
outpath := filepath.Join(cdir, "nixos")
os.MkdirAll(outpath, 0755)
t.Cleanup(func() {
os.RemoveAll(filepath.Join(outpath, d.name)) // makes the disk image a candidate for GC
})
cmd := exec.Command("nixos-generate", "-f", "qcow", "-o", filepath.Join(outpath, d.name), "-c", fname)
if *verboseNixOutput {
cmd.Stdout = logger.FuncWriter(t.Logf)
cmd.Stderr = logger.FuncWriter(t.Logf)
} else {
fname := fmt.Sprintf("nix-build-%s-%s", os.Getenv("GITHUB_RUN_NUMBER"), strings.Replace(t.Name(), "/", "-", -1))
t.Logf("writing nix logs to %s", fname)
fout, err := os.Create(fname)
if err != nil {
t.Fatalf("can't make log file for nix build: %v", err)
}
cmd.Stdout = fout
cmd.Stderr = fout
defer fout.Close()
}
cmd.Env = append(os.Environ(), "NIX_PATH=nixpkgs="+d.url)
cmd.Dir = outpath
if err := cmd.Run(); err != nil {
t.Fatalf("error while making NixOS image for %s: %v", d.name, err)
}
if !*verboseNixOutput {
t.Log("done")
}
return filepath.Join(outpath, d.name, "nixos.qcow2")
}