coverage.sh

@@ -89,6 +89,13 @@ if [ ! -e shared/tarfilter ] || [ tarfilter -nt shared/tarfilter ]; then
 		cp -a /usr/bin/mmtarfilter shared/tarfilter
 	fi
 fi
+if [ ! -e shared/proxysolver ] || [ proxysolver -nt shared/proxysolver ]; then
+	if [ -e ./proxysolver ]; then
+		cp -a proxysolver shared
+	else
+		cp -a /usr/lib/apt/solvers/mmdebstrap-dump-solution shared/proxysolver
+	fi
+fi
 if [ ! -e shared/ldconfig.fakechroot ] || [ ldconfig.fakechroot -nt shared/ldconfig.fakechroot ]; then
 	if [ -e ./ldconfig.fakechroot ]; then
 		cp -a ldconfig.fakechroot shared
@@ -1526,7 +1533,7 @@ else
 	skipped=$((skipped+1))
 fi
 
-print_header "mode=$defaultmode,variant=apt: file:// mirror"
+print_header "mode=$defaultmode,variant=apt: fail with file:// mirror"
 cat << END > shared/test.sh
 #!/bin/sh
 set -eu
@@ -1535,9 +1542,13 @@ if [ ! -e /mmdebstrap-testenv ]; then
 	echo "this test requires the cache directory to be mounted on /mnt and should only be run inside a container" >&2
 	exit 1
 fi
-$CMD --mode=$defaultmode --variant=apt $DEFAULT_DIST /tmp/debian-chroot.tar "deb file:///mnt/cache/debian $DEFAULT_DIST main"
-tar -tf /tmp/debian-chroot.tar | sort | diff -u tar1.txt -
+ret=0
+$CMD --mode=$defaultmode --variant=apt $DEFAULT_DIST /tmp/debian-chroot.tar "deb file:///mnt/cache/debian unstable main" || ret=\$?
 rm /tmp/debian-chroot.tar
+if [ "\$ret" = 0 ]; then
+	echo expected failure but got exit \$ret >&2
+	exit 1
+fi
 END
 if [ "$HAVE_QEMU" = "yes" ]; then
 	./run_qemu.sh
@@ -3068,7 +3079,7 @@ $CMD \$include --mode=$defaultmode --variant=$variant \
 	--setup-hook='sync-in "'"\$tmpdir"'" /var/cache/apt/archives/partial' \
 	$DEFAULT_DIST - $mirror > test1.tar
 cmp orig.tar test1.tar
-$CMD \$include --mode=$defaultmode --variant=$variant \
+$CMD \$include --mode=$defaultmode --variant=$variant --skip=download/empty \
 	--customize-hook='touch "\$1"/var/cache/apt/archives/partial' \
 	--setup-hook='mkdir -p "\$1"/var/cache/apt/archives/' \
 	--setup-hook='sync-in "'"\$tmpdir"'" /var/cache/apt/archives/' \
@@ -3749,4 +3760,4 @@ if [ "$((skipped+runtests))" -ne "$total" ]; then
 	exit 1
 fi
 
-rm shared/test.sh shared/tar1.txt shared/tar2.txt shared/pkglist.txt shared/doc-debian.tar.list shared/mmdebstrap shared/taridshift shared/tarfilter
+rm shared/test.sh shared/tar1.txt shared/tar2.txt shared/pkglist.txt shared/doc-debian.tar.list shared/mmdebstrap shared/taridshift shared/tarfilter shared/proxysolver

mmdebstrap

@@ -874,9 +874,28 @@ sub run_dpkg_progress {
 sub run_apt_progress {
     my $options = shift;
     my @debs    = @{ $options->{PKGS} // [] };
+    my $tmpedsp;
+    if (exists $options->{EDSP_RES}) {
+        (undef, $tmpedsp) = tempfile(
+            "mmdebstrap.edsp.XXXXXXXXXXXX",
+            OPEN   => 0,
+            TMPDIR => 1
+        );
+    }
     my $get_exec = sub {
         my @prefix = ();
         my @opts   = ();
+        if (exists $options->{EDSP_RES}) {
+            push @prefix, 'env', "APT_EDSP_DUMP_FILENAME=$tmpedsp";
+            if (-e "./proxysolver") {
+                # for development purposes, use the current directory if it
+                # contains a file called proxysolver
+                push @opts, ("-oDir::Bin::solvers=" . getcwd()),
+                  '--solver=proxysolver';
+            } else {
+                push @opts, '--solver=mmdebstrap-dump-solution';
+            }
+        }
         return (
             @prefix,
             @{ $options->{ARGV} },
@@ -931,44 +950,36 @@ sub run_apt_progress {
         }
     };
     run_progress $get_exec, $line_handler, $line_has_error, $options->{CHDIR};
-    return;
-}
-
-sub run_apt_download_progress {
-    my $options = shift;
-    my $tmplistofdebs;
-    if ($options->{dryrun}) {
-        info "simulate downloading packages with apt...";
-    } else {
-        info "downloading packages with apt...";
-        (undef, $tmplistofdebs) = tempfile(
-            "mmdebstrap.listofdebs.XXXXXXXXXXXX",
-            OPEN   => 0,
-            TMPDIR => 1
-        );
+    if (exists $options->{EDSP_RES}) {
+        info "parsing EDSP results...";
+        open my $fh, '<', $tmpedsp
+          or error "failed to open $tmpedsp for reading: $!";
+        my $inst = 0;
+        my $pkg;
+        my $ver;
+        while (my $line = <$fh>) {
+            chomp $line;
+            if ($line ne "") {
+                if ($line =~ /^Install: \d+/) {
+                    $inst = 1;
+                } elsif ($line =~ /^Package: (.*)/) {
+                    $pkg = $1;
+                } elsif ($line =~ /^Version: (.*)/) {
+                    $ver = $1;
+                }
+                next;
+            }
+            if ($inst == 1 && defined $pkg && defined $ver) {
+                push @{ $options->{EDSP_RES} }, [$pkg, $ver];
+            }
+            $inst = 0;
+            undef $pkg;
+            undef $ver;
         }
-    run_apt_progress({
-            ARGV => [
-                'apt-get',
-                '--yes',
-                '-oDebug::pkgDpkgPm=1',
-                '-oDir::Log=/dev/null',
-                $options->{dryrun}
-                ? '-oAPT::Get::Simulate=true'
-                : "-oDpkg::Pre-Install-Pkgs::=cat > $tmplistofdebs",
-                @{ $options->{APT_ARGV} },
-            ],
-        });
-    if ($tmplistofdebs) {
-        open my $fh, '<', $tmplistofdebs
-          or error "failed to open $tmplistofdebs for reading: $!";
-        my @listofdebs = <$fh>;
         close $fh;
-        unlink $tmplistofdebs;
-        chomp(@listofdebs);
-        return @listofdebs;
+        unlink $tmpedsp;
     }
-    return [];
+    return;
 }
 
 sub run_chroot {
@@ -2023,14 +2034,26 @@ sub run_update() {
 sub run_download() {
     my $options = shift;
 
+    # We use /var/cache/apt/archives/ to figure out which packages apt chooses
+    # to install. That's why the directory must be empty if:
+    #  - /var/cache/apt/archives exists, and
+    #  - no simulation run is done, and
+    #  - the variant is not extract or custom or the number to be
+    #    installed packages not zero
+    #
+    # We could also unconditionally use the proxysolver and then "apt-get
+    # download" any missing packages but using the proxysolver requires
+    # /usr/lib/apt/solvers/apt from the apt-utils package and we want to avoid
+    # that dependency.
+    #
     # In the future we want to replace downloading packages with "apt-get
-    # install" and installing them with dpkg by just installing the essential
-    # packages with apt from the outside with DPkg::Chroot-Directory.
-    # We are not doing that because then the preinst script of base-passwd will
-    # not be called early enough and packages will fail to install because they
-    # are missing /etc/passwd.
+    # install --download-only" and installing them with dpkg by just installing
+    # the essential packages with apt from the outside with
+    # DPkg::Chroot-Directory. We are not doing that because then the preinst
+    # script of base-passwd will not be called early enough and packages will
+    # fail to install because they are missing /etc/passwd.
     my @cached_debs = ();
-    my @dl_debs;
+    my @dl_debs     = ();
     if (
         !$options->{dryrun}
         && ((none { $_ eq $options->{variant} } ('extract', 'custom'))
@@ -2050,6 +2073,14 @@ sub run_download() {
             push @cached_debs, $deb;
         }
         closedir $dh;
+        if (scalar @cached_debs > 0) {
+            if (any { $_ eq 'download/empty' } @{ $options->{skip} }) {
+                info "skipping download/empty as requested";
+            } else {
+                error("/var/cache/apt/archives/ inside the chroot contains: "
+                      . (join ', ', (sort @cached_debs)));
+            }
+        }
     }
 
     # To figure out the right package set for the apt variant we can use:
@@ -2063,7 +2094,7 @@ sub run_download() {
             info "nothing to download -- skipping...";
             return ([], []);
         }
-        my @apt_argv = ['install'];
+        my %pkgs_to_install;
         for my $incl (@{ $options->{include} }) {
             for my $pkg (split /[,\s]+/, $incl) {
                 # strip leading and trailing whitespace
@@ -2072,15 +2103,32 @@ sub run_download() {
                 if ($pkg eq '') {
                     next;
                 }
-                push @apt_argv, $pkg;
+                $pkgs_to_install{$pkg} = ();
             }
         }
 
-        @dl_debs = run_apt_download_progress({
-                APT_ARGV => @apt_argv,
-                dryrun   => $options->{dryrun},
-            },
-        );
+        my %result = ();
+        if ($options->{dryrun}) {
+            info "simulate downloading packages with apt...";
+        } else {
+            # if there are already packages in /var/cache/apt/archives/, we
+            # need to use our proxysolver to obtain the solution chosen by apt
+            if (scalar @cached_debs > 0) {
+                $result{EDSP_RES} = \@dl_debs;
+            }
+            info "downloading packages with apt...";
+        }
+        run_apt_progress({
+                ARGV => [
+                    'apt-get',
+                    '--yes',
+                    '-oApt::Get::Download-Only=true',
+                    $options->{dryrun} ? '-oAPT::Get::Simulate=true' : (),
+                    'install'
+                ],
+                PKGS => [keys %pkgs_to_install],
+                %result
+            });
     } elsif ($options->{variant} eq 'apt') {
         # if we just want to install Essential:yes packages, apt and their
         # dependencies then we can make use of libapt treating apt as
@@ -2095,11 +2143,27 @@ sub run_download() {
         #                  remind me in 5+ years that I said that after I wrote
         #                  in the bugreport: "Are you crazy?!? Nobody in his
         #                  right mind would even suggest depending on it!")
-        @dl_debs = run_apt_download_progress({
-                APT_ARGV => ['dist-upgrade'],
-                dryrun   => $options->{dryrun},
-            },
-        );
+        my %result = ();
+        if ($options->{dryrun}) {
+            info "simulate downloading packages with apt...";
+        } else {
+            # if there are already packages in /var/cache/apt/archives/, we
+            # need to use our proxysolver to obtain the solution chosen by apt
+            if (scalar @cached_debs > 0) {
+                $result{EDSP_RES} = \@dl_debs;
+            }
+            info "downloading packages with apt...";
+        }
+        run_apt_progress({
+                ARGV => [
+                    'apt-get',
+                    '--yes',
+                    '-oApt::Get::Download-Only=true',
+                    $options->{dryrun} ? '-oAPT::Get::Simulate=true' : (),
+                    'dist-upgrade'
+                ],
+                %result
+            });
     } elsif (
         any { $_ eq $options->{variant} }
         ('essential', 'standard', 'important', 'required', 'buildd')
@@ -2108,8 +2172,23 @@ sub run_download() {
         # 17:27 < DonKult> (?essential includes 'apt' through)
         # 17:30 < josch> DonKult: no, because pkgCacheGen::ForceEssential ",";
         # 17:32 < DonKult> touché
-        @dl_debs = run_apt_download_progress({
-                APT_ARGV => [
+        my %result = ();
+        if ($options->{dryrun}) {
+            info "simulate downloading packages with apt...";
+        } else {
+            # if there are already packages in /var/cache/apt/archives/, we
+            # need to use our proxysolver to obtain the solution chosen by apt
+            if (scalar @cached_debs > 0) {
+                $result{EDSP_RES} = \@dl_debs;
+            }
+            info "downloading packages with apt...";
+        }
+        run_apt_progress({
+                ARGV => [
+                    'apt-get',
+                    '--yes',
+                    '-oApt::Get::Download-Only=true',
+                    $options->{dryrun} ? '-oAPT::Get::Simulate=true' : (),
                     'install',
                     '?narrow('
                       . (
@@ -2124,31 +2203,76 @@ sub run_download() {
                       . $options->{nativearch}
                       . '),?essential)'
                 ],
-                dryrun => $options->{dryrun},
-            },
-        );
+                %result
+            });
     } else {
         error "unknown variant: $options->{variant}";
     }
 
     my @essential_pkgs;
-    # strip the the chroot directory from the filenames
-    foreach my $deb (@dl_debs) {
-        if (rindex $deb, $options->{root}, 0) {
-            if (-e "$options->{root}/$deb") {
-                push @essential_pkgs, $deb;
+    if (scalar @cached_debs > 0 && scalar @dl_debs > 0) {
+        my $archives = "/var/cache/apt/archives/";
+        # for each package in @dl_debs, check if it's in
+        # /var/cache/apt/archives/ and add it to @essential_pkgs
+        foreach my $p (@dl_debs) {
+            my ($pkg, $ver_epoch) = @{$p};
+            # apt appends the architecture at the end of the package name
+            ($pkg, my $arch) = split ':', $pkg, 2;
+            # apt replaces the colon by its percent encoding %3a
+            my $ver = $ver_epoch;
+            $ver =~ s/:/%3a/;
+            # the architecture returned by apt is the native architecture.
+            # Since we don't know whether the package is architecture
+            # independent or not, we first try with the native arch and then
+            # with "all" and only error out if neither exists.
+            if (-e "$options->{root}/$archives/${pkg}_${ver}_$arch.deb") {
+                push @essential_pkgs, "$archives/${pkg}_${ver}_$arch.deb";
+            } elsif (-e "$options->{root}/$archives/${pkg}_${ver}_all.deb") {
+                push @essential_pkgs, "$archives/${pkg}_${ver}_all.deb";
             } else {
-                error "package file $deb not accessible from chroot directory"
-                  . " -- use copy:// instead of file:// or a bind-mount";
+                error(  "cannot find package for $pkg:$arch (= $ver_epoch) "
+                      . "in /var/cache/apt/archives/");
             }
+        }
+    } else {
+        # collect the .deb files that were downloaded by apt from the content
+        # of /var/cache/apt/archives/
+        if (!$options->{dryrun}) {
+            my $apt_archives = "/var/cache/apt/archives/";
+            opendir my $dh, "$options->{root}/$apt_archives"
+              or error "cannot read $apt_archives";
+            while (my $deb = readdir $dh) {
+                if ($deb !~ /\.deb$/) {
                     next;
                 }
-        if (-e $deb) {
-            push @essential_pkgs, substr($deb, length($options->{root}));
-        } else {
-            error "cannot find package file $deb";
+                $deb = "$apt_archives/$deb";
+                if (!-f "$options->{root}/$deb") {
+                    next;
+                }
+                push @essential_pkgs, $deb;
+            }
+            closedir $dh;
+
+            if (scalar @essential_pkgs == 0) {
+                # check if a file:// URI was used
+                open(my $pipe_apt, '-|', 'apt-get', 'indextargets', '--format',
+                    '$(URI)', 'Created-By: Packages')
+                  or error "cannot start apt-get indextargets: $!";
+                while (my $uri = <$pipe_apt>) {
+                    if ($uri =~ /^file:\/\//) {
+                        error
+                          "nothing got downloaded -- use copy:// instead of"
+                          . " file://";
                     }
                 }
+                error "nothing got downloaded";
+            }
+        }
+    }
+    # Unpack order matters. Since we create this list using two different
+    # methods but we want both methods to have the same result, we sort the
+    # list before returning it.
+    @essential_pkgs = sort @essential_pkgs;
 
     return (\@essential_pkgs, \@cached_debs);
 }
@@ -6579,13 +6703,15 @@ the B<setup> step. This can be disabled using B<--skip=update>.
 
 =item B<download>
 
-In the B<extract> and B<custom> variants, C<apt-get install> is used to
-download all the packages requested via the B<--include> option. The B<apt>
-variant uses the fact that libapt treats the C<apt> packages as implicitly
-essential to download only all C<Essential:yes> packages plus apt using
-C<apt-get dist-upgrade>. In the remaining variants, all Packages files
-downloaded by the B<update> step are inspected to find the C<Essential:yes>
-package set as well as all packages of the required priority.
+Checks whether F</var/cache/apt/archives/> is empty. This can be disabled with
+B<--skip=download/empty>. In the B<extract> and B<custom> variants, C<apt-get
+--download-only install> is used to download all the packages requested via the
+B<--include> option. The B<apt> variant uses the fact that libapt treats the
+C<apt> packages as implicitly essential to download only all C<Essential:yes>
+packages plus apt using C<apt-get --download-only dist-upgrade>. In the
+remaining variants, all Packages files downloaded by the B<update> step are
+inspected to find the C<Essential:yes> package set as well as all packages of
+the required priority.
 
 =item B<extract>
 
@@ -6813,7 +6939,7 @@ apt-cacher-ng, you can use the B<sync-in> and B<sync-out> special hooks to
 synchronize a directory outside the chroot with F</var/cache/apt/archives>
 inside the chroot.
 
-    $ mmdebstrap --variant=apt --skip=essential/unlink \
+    $ mmdebstrap --variant=apt --skip=download/empty --skip=essential/unlink \
         --setup-hook='mkdir -p ./cache "$1"/var/cache/apt/archives/' \
         --setup-hook='sync-in ./cache /var/cache/apt/archives/' \
         --customize-hook='sync-out /var/cache/apt/archives ./cache' \
@@ -6954,6 +7080,12 @@ as the non-root user, then as a workaround you could run C<chmod 600
 /etc/dpkg/dpkg.cfg.d/*> so that the config files are only accessible by the
 root user. See Debian bug #808203.
 
+The C<file://> URI type cannot be used to install the essential packages. This
+is because B<mmdebstrap> uses dpkg to install the packages that apt places into
+F</var/cache/apt/archives> but with C<file://> apt will not copy the files even
+with C<--download-only>. Use C<copy://> instead, which is equivalent to
+C<file://> but copies the archives into F</var/cache/apt/archives>.
+
 With apt versions before 2.1.16, setting C<[trusted=yes]> or
 C<Acquire::AllowInsecureRepositories "1"> to allow signed archives without a
 known public key or unsigned archives will fail because of a gpg warning in the

proxysolver

@@ -0,0 +1,56 @@
+#!/usr/bin/env python3
+#
+# This script is in the public domain
+#
+# Author: Johannes Schauer Marin Rodrigues <josch@mister-muffin.de>
+#
+# thin layer around /usr/lib/apt/solvers/apt, so that we can capture the solver
+# result
+#
+# we set Debug::EDSP::WriteSolution=yes so that Install stanzas also come with
+# Package and Version fields. That way, we do not also have to parse the EDSP
+# request and spend time matching ID numbers
+
+import subprocess
+import sys
+import os
+import getpass
+
+if not os.path.exists("/usr/lib/apt/solvers/apt"):
+    print(
+        """Error: ERR_NO_SOLVER
+Message: The external apt solver doesn't exist. You must install the apt-utils package.
+"""
+    )
+    exit()
+
+fname = os.environ.get("APT_EDSP_DUMP_FILENAME")
+if fname is None:
+    print(
+        """Error: ERR_NO_FILENAME
+Message: You have to set the environment variable APT_EDSP_DUMP_FILENAME
+ to a valid filename to store the dump of EDSP solver input in.
+ For example with: export APT_EDSP_DUMP_FILENAME=/tmp/dump.edsp
+"""
+    )
+    exit()
+
+try:
+    with open(fname, "w") as f:
+        with subprocess.Popen(
+            ["/usr/lib/apt/solvers/apt", "-oDebug::EDSP::WriteSolution=yes"],
+            stdin=sys.stdin.fileno(),
+            stdout=subprocess.PIPE,
+            bufsize=0,  # unbuffered
+            text=True,  # open in text mode
+        ) as p:
+            for line in p.stdout:
+                print(line, end="")
+                f.write(line)
+except (FileNotFoundError, PermissionError) as e:
+    print(
+        """Error: ERR_CREATE_FILE
+Message: Writing EDSP solver input to file '%s' failed as it couldn't be created!
+"""
+        % fname
+    )