Add an autopkgtest covering #817236 and various other sanity checks

Because debootstrap is relatively slow, I've named the test according
to what is being bootstrapped (Debian testing) rather than the checks
that are performed, with the intention that additional checks can
be added to it.

Signed-off-by: Simon McVittie <smcv@debian.org>

4 files changed, 358 insertions, 0 deletions

diff --git a/debian/tests/control b/debian/tests/control
new file mode 100644
index 0000000..12d78c7
--- /dev/null
+++ b/debian/tests/control
@@ -0,0 +1,10 @@
+Tests: debian-testing
+Depends:
+ debootstrap,
+ libdistro-info-perl,
+ libdpkg-perl,
+ libipc-run-perl,
+ perl,
+ systemd [linux-any],
+ systemd-container [linux-any],
+Restrictions: allow-stderr, needs-root
diff --git a/debian/tests/debian-testing b/debian/tests/debian-testing
new file mode 100755
index 0000000..3f8e81a
--- /dev/null
+++ b/debian/tests/debian-testing
@@ -0,0 +1,270 @@
+#!/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 $extra_argv = $params{extra_argv} || [];
+
+    my $response = capture([qw(unshare -m),
+        "$srcdir/debian/tests/fake/schroot-1.6.10-3", @{$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 $response = capture([qw(unshare -m),
+        "$srcdir/debian/tests/fake/pbuilder-0.228.4-1", $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);
+
+    # Use unshare -m to make sure the /dev mount gets cleaned up on exit, even
+    # on failures
+    check_fake_schroot(%params, reference => $reference);
+
+    # https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=817236
+    if (Dpkg::Version->new($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']);
+    }
+
+    # 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:
diff --git a/debian/tests/fake/pbuilder-0.228.4-1 b/debian/tests/fake/pbuilder-0.228.4-1
new file mode 100755
index 0000000..95191b7
--- /dev/null
+++ b/debian/tests/fake/pbuilder-0.228.4-1
@@ -0,0 +1,31 @@
+#!/bin/sh
+# fake/pbuilder-0.228.4-1 -- emulate how pbuilder/0.228.4-1 would chroot.
+# It mounts /dev/pts, without explicitly requesting a new instance or a
+# usable /dev/pts/ptmx.
+# (There is of course a lot more that it does, but these are the parts that
+# affect pty users like script(1).)
+#
+# Copyright © 2017 Simon McVittie
+# SPDX-License-Identifier: MIT
+# (see debian/copyright)
+
+set -e
+
+chroot="$1"
+shift
+if test -z "$chroot" || test -z "$1"; then
+	echo "Usage: $0 CHROOT COMMAND...">&2
+	exit 2
+fi
+
+mkdir -p "$chroot/dev/pts"
+mount -t devpts none "$chroot/dev/pts" -onoexec,nosuid,gid=5,mode=620
+
+ls -l "$chroot/dev/ptmx" | sed -e 's/^/# fake-pbuilder: /' >&2
+ls -l "$chroot/dev/pts/ptmx" | sed -e 's/^/# fake-pbuilder: /' >&2
+
+e=0
+chroot "$chroot" "$@" || e=$?
+
+umount "$chroot/dev/pts"
+exit "$e"
diff --git a/debian/tests/fake/schroot-1.6.10-3 b/debian/tests/fake/schroot-1.6.10-3
new file mode 100755
index 0000000..00d3531
--- /dev/null
+++ b/debian/tests/fake/schroot-1.6.10-3
@@ -0,0 +1,47 @@
+#!/bin/sh
+# fake/schroot-1.6.10-3 -- emulate how schroot/1.6.10-3 would chroot.
+# It bind-mounts /dev/pts and maybe /dev from the host system.
+# (There is of course a lot more that it does, but these are the parts that
+# affect pty users like script(1).)
+#
+# Copyright © 2017 Simon McVittie
+# SPDX-License-Identifier: MIT
+# (see debian/copyright)
+
+set -e
+
+# /etc/schroot/default/fstab
+bind_dev=yes
+
+while true; do
+	case "$1" in
+		(--sbuild)
+			shift
+			# /etc/schroot/sbuild/fstab
+			bind_dev=no
+			;;
+		(*)
+			break
+	esac
+done
+
+chroot="$1"
+shift
+if test -z "$chroot" || test -z "$1"; then
+	echo "Usage: $0 CHROOT COMMAND...">&2
+	exit 2
+fi
+
+[ "$bind_dev" = no ] || mount --bind /dev "$chroot/dev"
+mount --bind /dev/pts "$chroot/dev/pts"
+
+ls -l "$chroot/dev/ptmx" | sed -e 's/^/# fake-schroot: /' >&2
+ls -l "$chroot/dev/pts/ptmx" | sed -e 's/^/# fake-schroot: /' >&2
+
+e=0
+chroot "$chroot" "$@" || e=$?
+
+umount "$chroot/dev/pts"
+[ "$bind_dev" = no ] || umount "$chroot/dev"
+
+exit "$e"