#!/usr/bin/perl
# Verify that debootstrap'ing Debian testing produces a usable chroot,
# and in particular that using it with early 2017 versions of schroot and
# pbuilder results in working pseudo-terminals (#817236)
#
# Copyright © 2017 Simon McVittie
# SPDX-License-Identifier: MIT
# (see debian/copyright)

use strict;
use warnings;

use Cwd qw(getcwd);
use Debian::DistroInfo;
use Dpkg::Version;
use IPC::Run qw(run);
use Test::More;

my $srcdir = getcwd;

sub verbose_run {
    my $argv = shift;
    diag("Running: @{$argv}");
    return run($argv, @_);
}

sub capture {
    my $output;
    my $argv = shift;
    ok(verbose_run($argv, '>', \$output), "@{$argv}");
    chomp $output;
    return $output;
}

sub check_fake_schroot {
    my %params = @_;
    my $reference = $params{reference};
    my $version = $params{version} || '1.6.10-3';
    my $extra_argv = $params{extra_argv} || [];

    # Use unshare -m to make sure the /dev mount gets cleaned up on exit, even
    # on failures
    my $response = capture([qw(unshare -m),
        "$srcdir/debian/tests/fake/schroot-$version", @{$extra_argv},
            $params{chroot},
        qw(runuser -u nobody --),
        qw(script -q -c), 'cat /etc/debian_version', '/dev/null']);
    $response =~ s/\r//g;
    is($response, $reference, 'script(1) should work under (fake) schroot');
}

sub check_fake_pbuilder {
    my %params = @_;
    my $reference = $params{reference};
    my $version = $params{version} || '0.228.4-1';

    my $response = capture([qw(unshare -m),
        "$srcdir/debian/tests/fake/pbuilder-$version", $params{chroot},
        qw(runuser -u nobody --),
        qw(script -q -c), 'cat /etc/debian_version', '/dev/null']);
    $response =~ s/\r//g;
    is($response, $reference,
        'script(1) should work under (fake) pbuilder');
}

sub check_chroot {
    my %params = @_;
    my $chroot = $params{chroot};
    my $response;

    ok(-f "$chroot/etc/debian_version",
        'chroot should have /etc/debian_version');
    ok(-x "$chroot/usr/bin/env",
        'chroot should have /usr/bin/env which is Essential');
    ok(-x "$chroot/usr/bin/hello", 'chroot should have /usr/bin/hello due to --include');
    ok(-d "$chroot/usr/share/doc", 'chroot should have /usr/share/doc');

    ok(-c "$chroot/dev/full", '/dev/full should be a character device');
    is(capture(['/usr/bin/stat', '--printf=%t %T %a', "$chroot/dev/full"]),
        '1 7 666', '/dev/full should be device 1,7 with 0666 permissions');
    ok(-c "$chroot/dev/null");
    is(capture(['/usr/bin/stat', '--printf=%t %T %a', "$chroot/dev/null"]),
        '1 3 666', '/dev/null should be device 1,3 with 0666 permissions');

    my $did_mknod_ptmx;

    if (-l "$chroot/dev/ptmx") {
        # Necessary if debootstrap is run inside some containers, see
        # https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=817236#77
        diag("/dev/ptmx is a symbolic link");
        like(readlink("$chroot/dev/ptmx"), qr{(?:/dev/)?pts/ptmx},
            'if /dev/ptmx is a symlink it should be to /dev/pts/ptmx');
        $did_mknod_ptmx = 0;
    }
    else {
        diag("/dev/ptmx is not a symbolic link");
        ok(-c "$chroot/dev/ptmx",
            'if /dev/pts is not a symlink it should be a character device');
        is(capture(['/usr/bin/stat', '--printf=%t %T %a',
                    "$chroot/dev/ptmx"]), '5 2 666',
            'if /dev/pts is a device node it should be 5,2 with 0666 permissions');
        $did_mknod_ptmx = 1;
    }

    if ($params{can_mknod_ptmx}) {
        ok($did_mknod_ptmx, 'able to mknod ptmx so should have done so');
    }

    my $reference = capture(['cat', "$chroot/etc/debian_version"]);

    is(capture([qw(chroot chroot.d runuser -u nobody --
                cat /etc/debian_version)]),
        $reference);

    check_fake_schroot(%params, reference => $reference);
    check_fake_schroot(%params, reference => $reference, version => 'proposed');
    check_fake_schroot(%params, reference => $reference, version => 'proposed',
        extra_argv => ['--sbuild']);

    # https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=817236
    if (Dpkg::Version->new($params{kernel}) < Dpkg::Version->new('4.7') &&
            defined $params{container} && $params{container} eq 'lxc') {
        TODO: {
            local $TODO = "schroot --sbuild doesn't work in lxc on older ".
                "kernels";
            check_fake_schroot(%params, reference => $reference,
                extra_argv => ['--sbuild']);
        }
    }
    elsif (! $params{can_mknod_ptmx}) {
        TODO: {
            local $TODO = "schroot --sbuild doesn't work when /dev/ptmx is ".
                "a symlink to /dev/pts/ptmx";
            check_fake_schroot(%params, reference => $reference,
                extra_argv => ['--sbuild']);
        }
    }
    else {
        check_fake_schroot(%params, reference => $reference,
            extra_argv => ['--sbuild']);
    }

    check_fake_pbuilder(%params, reference => $reference,
        version => 'proposed');

    # https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=817236
    if (! $params{can_mknod_ptmx}) {
        TODO: {
            local $TODO = "schroot --sbuild doesn't work when /dev/ptmx is ".
                "a symlink to /dev/pts/ptmx";
            check_fake_pbuilder(%params, reference => $reference);
        }
    }
    else {
        check_fake_pbuilder(%params, reference => $reference);
    }
}

my $mirror = 'http://deb.debian.org/debian';
my $tmp = $ENV{AUTOPKGTEST_TMP} || $ENV{ADTTMP};
die "no autopkgtest temporary directory specified" unless $tmp;
chdir $tmp or die "chdir $tmp: $!";

$ENV{LC_ALL} = 'C.UTF-8';

# Try to inherit a Debian mirror from the host
foreach my $file ('/etc/apt/sources.list',
        glob('/etc/apt/sources.list.d/*.list')) {
    open(my $fh, '<', $file);
    while (<$fh>) {
        if (m{^deb\s+(http://[-a-zA-Z0-9.:]+/debian)\s}) {
            $mirror = $1;
            last;
        }
    }
    close $fh;
}

if (run(['ischroot'], '>&2')) {
    diag("In a chroot according to ischroot(1)");
}
else {
    diag("Not in a chroot according to ischroot(1)");
}

my $virtualization;
if ($^O ne 'linux') {
    diag("Cannot use systemd-detect-virt on non-Linux");
}
elsif (run(['systemd-detect-virt', '--vm'], '>', \$virtualization)) {
    chomp $virtualization;
    diag("Virtualization: $virtualization");
}
else {
    $virtualization = undef;
    diag("Virtualization: (not in a virtual machine)");
}

my $in_container = 0;
my $container;
if ($^O ne 'linux') {
    diag("Cannot use systemd-detect-virt on non-Linux");
}
elsif (run(['systemd-detect-virt', '--container'], '>', \$container)) {
    $in_container = 1;
    chomp $container;
    diag("Container: $container");
}
else {
    $container = undef;
    diag("Container: (not in a container)");
}

my $kernel = capture([qw(uname -r)]);
chomp $kernel;

open(my $fh, '<', '/proc/self/mountinfo');
while (<$fh>) {
    chomp;
    diag("mountinfo: $_");
}
close $fh;

my $can_mknod_ptmx;
if (run([qw(mknod -m000 ptmx c 5 2)], '&>', '/dev/null')) {
    diag("mknod ptmx succeeded");
    $can_mknod_ptmx = 1;
}
else {
    diag("mknod ptmx failed, are we in a container?");
    $can_mknod_ptmx = 0;
}

my $distro_info = DebianDistroInfo->new;
my $testing = $distro_info->testing;

if (!verbose_run(['debootstrap',
            '--include=debootstrap,debian-archive-keyring,gnupg,hello',
            '--variant=minbase',
            $testing, 'chroot.d', $mirror], '>&2')) {
    BAIL_OUT("debootstrap failed: $?");
}

check_chroot(chroot => 'chroot.d', can_mknod_ptmx => $can_mknod_ptmx,
    kernel => $kernel, container => $container);

if ($^O ne 'linux') {
    diag("Cannot use systemd-nspawn on non-Linux");
}
elsif ($in_container) {
    diag('in a container according to systemd --container, not trying to '.
        'use systemd-nspawn');
}
elsif (! -d '/run/systemd/system') {
    diag('systemd not booted, not trying to use systemd-nspawn');
}
else {
    if (!verbose_run(['systemd-nspawn', '-D', 'chroot.d',
            "--bind=$ENV{ADTTMP}:/mnt",
            '--bind-ro=/usr/sbin/debootstrap',
            '--bind-ro=/usr/share/debootstrap',
            '--',
            'debootstrap', '--include=hello', '--variant=minbase',
            $testing, '/mnt/from-nspawn.d', $mirror], '>&2')) {
        BAIL_OUT("debootstrap wrapped in systemd-nspawn failed: $?");
    }

    check_chroot(chroot => 'from-nspawn.d', can_mknod_ptmx => 0,
        kernel => $kernel, container => "nspawn");
}

if (!run([qw(rm -fr --one-file-system chroot.d)], '>&2')) {
    BAIL_OUT('Unable to remove chroot.d');
}

done_testing;

# vim:set sw=4 sts=4 et: