From e523741610a4ed8579642bfc755956f64c847ef3 Mon Sep 17 00:00:00 2001
From: Johannes Schauer Marin Rodrigues <josch@mister-muffin.de>
Date: Sat, 17 Jun 2023 13:46:32 +0200
Subject: [PATCH] add hooks/copy-host-apt-sources-and-preferences

---
 .../customize00.pl                            | 44 +++++++++++++++++++
 .../setup00.sh                                | 43 ++++++++++++++++++
 2 files changed, 87 insertions(+)
 create mode 100755 hooks/copy-host-apt-sources-and-preferences/customize00.pl
 create mode 100755 hooks/copy-host-apt-sources-and-preferences/setup00.sh

diff --git a/hooks/copy-host-apt-sources-and-preferences/customize00.pl b/hooks/copy-host-apt-sources-and-preferences/customize00.pl
new file mode 100755
index 0000000..53f6059
--- /dev/null
+++ b/hooks/copy-host-apt-sources-and-preferences/customize00.pl
@@ -0,0 +1,44 @@
+#!/usr/bin/perl
+#
+# This script makes sure that all packages that are installed both locally as
+# well as inside the chroot have the same version.
+#
+# It is implemented in Perl because there are no associative arrays in POSIX
+# shell.
+
+use strict;
+use warnings;
+
+sub get_pkgs {
+    my $root = shift;
+    my %pkgs = ();
+    open(my $fh, '-|', 'dpkg-query', "--root=$root", '--showformat',
+        '${binary:Package}=${Version}\n', '--show')
+      // die "cannot exec dpkg-query";
+    while (my $line = <$fh>) {
+        my ($pkg, $ver) = split(/=/, $line, 2);
+        $pkgs{$pkg} = $ver;
+    }
+    close $fh;
+    if ($? != 0) { die "failed to run dpkg-query" }
+    return %pkgs;
+}
+
+my %pkgs_local  = get_pkgs('/');
+my %pkgs_chroot = get_pkgs($ARGV[0]);
+
+my @diff = ();
+foreach my $pkg (keys %pkgs_chroot) {
+    next unless exists $pkgs_local{$pkg};
+    if ($pkgs_local{$pkg} ne $pkgs_chroot{$pkg}) {
+        push @diff, $pkg;
+    }
+}
+
+if (scalar @diff > 0) {
+    print STDERR "E: packages from the host and the chroot differ:\n";
+    foreach my $pkg (@diff) {
+	print STDERR "E: $pkg $pkgs_local{$pkg} $pkgs_chroot{$pkg}\n";
+    }
+    exit 1;
+}
diff --git a/hooks/copy-host-apt-sources-and-preferences/setup00.sh b/hooks/copy-host-apt-sources-and-preferences/setup00.sh
new file mode 100755
index 0000000..d04e6c8
--- /dev/null
+++ b/hooks/copy-host-apt-sources-and-preferences/setup00.sh
@@ -0,0 +1,43 @@
+#!/bin/sh
+
+set -eu
+
+if [ "${MMDEBSTRAP_VERBOSITY:-1}" -ge 3 ]; then
+	set -x
+fi
+
+if [ -n "${MMDEBSTRAP_SUITE:-}" ]; then
+	if [ "${MMDEBSTRAP_VERBOSITY:-1}" -ge 1 ]; then
+		echo "W: using a non-empty suite name $MMDEBSTRAP_SUITE does not make sense with this hook and might select the wrong Essential:yes package set" >&2
+	fi
+fi
+
+rootdir="$1"
+
+SOURCELIST="/etc/apt/sources.list"
+eval "$(apt-config shell SOURCELIST Dir::Etc::SourceList/f)"
+SOURCEPARTS="/etc/apt/sources.d/"
+eval "$(apt-config shell SOURCEPARTS Dir::Etc::SourceParts/d)"
+PREFERENCES="/etc/apt/preferences"
+eval "$(apt-config shell PREFERENCES Dir::Etc::Preferences/f)"
+PREFERENCESPARTS="/etc/apt/preferences.d/"
+eval "$(apt-config shell PREFERENCESPARTS Dir::Etc::PreferencesParts/d)"
+
+for f in "$SOURCELIST" \
+	"$SOURCEPARTS"/*.list \
+	"$SOURCEPARTS"/*.sources \
+	"$PREFERENCES" \
+	"$PREFERENCESPARTS"/*; do
+	[ -e "$f" ] || continue
+	if [ -e "$rootdir/$f" ]; then
+		if [ "${MMDEBSTRAP_VERBOSITY:-1}" -ge 2 ]; then
+			echo "I: $f already exists in chroot, appending..." >&2
+		fi
+		echo >> "$rootdir/$f"
+	fi
+	cat "$f" >> "$rootdir/$f"
+	if [ "${MMDEBSTRAP_VERBOSITY:-1}" -ge 3 ]; then
+		echo "D: contents of $f inside the chroot:" >&2
+		cat "$rootdir/$f" >&2
+	fi
+done