From: Richard Jones Date: Tue, 22 Sep 2009 18:50:21 +0000 (+0100) Subject: Add 'virt-rescue' command. X-Git-Tag: 1.0.72~10 X-Git-Url: http://git.annexia.org/?p=libguestfs.git;a=commitdiff_plain;h=1b21ed4f5d9307e87fad094ec177c90d5adb91ce Add 'virt-rescue' command. This command runs a "rescue appliance" against a virtual machine or disk image. This is useful for making ad-hoc interactive changes to virtual machines. $ virt-rescue --ro /dev/vg_trick/F11x64 Welcome to virt-rescue, the libguestfs rescue shell. Note: The contents of / are the rescue appliance. You have to mount the guest's partitions under /sysroot before you will be able to examine them. bash: cannot set terminal process group (-1): Inappropriate ioctl for device bash: no job control in this shell > mount /dev/vg_f11x64/lv_root /sysroot EXT4-fs (dm-0): barriers enabled kjournald2 starting: pid 269, dev dm-0:8, commit interval 5 seconds EXT4-fs (dm-0): internal journal on dm-0:8 EXT4-fs (dm-0): delayed allocation enabled EXT4-fs: file extents enabled EXT4-fs: mballoc enabled EXT4-fs (dm-0): mounted filesystem with ordered data mode > ls /sysroot/ bin dev home lib64 media opt root selinux sys usr boot etc lib lost+found mnt proc sbin srv tmp var > exit --- diff --git a/.gitignore b/.gitignore index beca741..3758092 100644 --- a/.gitignore +++ b/.gitignore @@ -74,6 +74,7 @@ html/recipes.html html/virt-cat.1.html html/virt-df.1.html html/virt-inspector.1.html +html/virt-rescue.1.html images/100kallnewlines images/100kallspaces images/100kallzeroes @@ -170,6 +171,7 @@ python/guestfs.py python/guestfs-py.c python/guestfs.pyc regressions/test1.img +rescue/virt-rescue.1 ruby/bindtests.rb ruby/ext/guestfs/extconf.h ruby/ext/guestfs/_guestfs.c diff --git a/HACKING b/HACKING index 7156bf7..a051d8a 100644 --- a/HACKING +++ b/HACKING @@ -122,6 +122,9 @@ python/ regressions/ Regression tests. +rescue/ + The virt-rescue tool. + ruby/ Ruby bindings. diff --git a/Makefile.am b/Makefile.am index 32853fc..043e84a 100644 --- a/Makefile.am +++ b/Makefile.am @@ -47,6 +47,9 @@ endif if HAVE_CAT SUBDIRS += cat endif +if HAVE_RESCUE +SUBDIRS += rescue +endif EXTRA_DIST = \ guestfs.pod guestfs-actions.pod guestfs-structs.pod \ diff --git a/TODO b/TODO index 12b1ce6..2833d46 100644 --- a/TODO +++ b/TODO @@ -264,3 +264,19 @@ quickly, eg: load ext2 Maybe it's better to create these on the fly? + +virt-rescue pty +--------------- + +See: +http://search.cpan.org/~rgiersig/IO-Tty-1.08/Pty.pm +http://www.perlmonks.org/index.pl?node_id=582185 + +Note that pty requires cooperation inside the C code too (there are +two sides to a pty, and one has to be handled after the fork). + +virt-rescue TERM +---------------- + +Pass TERM from the library, through the kernel command line, to the +init script. diff --git a/appliance/init b/appliance/init index 8b97590..545232c 100755 --- a/appliance/init +++ b/appliance/init @@ -65,7 +65,15 @@ if ! grep -sq guestfs_rescue=1 /proc/cmdline; then exec guestfsd -f fi +# Use appliance in rescue mode, also used by the virt-rescue command. TERM=linux ;# XXX library should pass this from library's environment PS1='> ' export TERM PS1 +echo +echo "Welcome to virt-rescue, the libguestfs rescue shell." +echo +echo "Note: The contents of / are the rescue appliance." +echo "You have to mount the guest's partitions under /sysroot" +echo "before you can examine them." +echo exec bash -i diff --git a/configure.ac b/configure.ac index beef03f..7554a59 100644 --- a/configure.ac +++ b/configure.ac @@ -653,7 +653,7 @@ for pm in Pod::Usage Getopt::Long Sys::Virt Data::Dumper XML::Writer Locale::Tex fi done if test "x$missing_perl_modules" = "xyes"; then - AC_MSG_WARN([some Perl modules required to compile virt-cat, virt-df and virt-inspector are missing]) + AC_MSG_WARN([some Perl modules required to compile virt-cat, virt-df, virt-inspector and virt-rescue are missing]) fi AM_CONDITIONAL([HAVE_CAT], @@ -662,6 +662,8 @@ AM_CONDITIONAL([HAVE_DF], [test "x$PERL" != "xno" -a "x$missing_perl_modules" != "xyes"]) AM_CONDITIONAL([HAVE_INSPECTOR], [test "x$PERL" != "xno" -a "x$missing_perl_modules" != "xyes"]) +AM_CONDITIONAL([HAVE_RESCUE], + [test "x$PERL" != "xno" -a "x$missing_perl_modules" != "xyes"]) dnl Library versioning. MAX_PROC_NR=`cat $srcdir/src/MAX_PROC_NR` @@ -700,6 +702,7 @@ AC_CONFIG_FILES([Makefile cat/Makefile df/Makefile inspector/Makefile + rescue/Makefile libguestfs.pc gnulib/lib/Makefile gnulib/tests/Makefile @@ -733,6 +736,8 @@ echo -n "virt-df ............................. " if test "x$HAVE_DF" = "x"; then echo "yes"; else echo "no"; fi echo -n "virt-inspector ...................... " if test "x$HAVE_INSPECTOR" = "x"; then echo "yes"; else echo "no"; fi +echo -n "virt-rescue ......................... " +if test "x$HAVE_RESCUE" = "x"; then echo "yes"; else echo "no"; fi echo "supermin appliance .................. $enable_supermin" echo echo "If any optional component is configured 'no' when you expected 'yes'" diff --git a/po/POTFILES.in b/po/POTFILES.in index 44e472b..5c70341 100644 --- a/po/POTFILES.in +++ b/po/POTFILES.in @@ -80,6 +80,7 @@ perl/lib/Sys/Guestfs.pm perl/lib/Sys/Guestfs/Lib.pm python/guestfs-py.c regressions/test-noexec-stack.pl +rescue/virt-rescue.pl ruby/ext/guestfs/_guestfs.c src/guestfs-actions.c src/guestfs-bindtests.c diff --git a/rescue/Makefile.am b/rescue/Makefile.am new file mode 100644 index 0000000..a9a533c --- /dev/null +++ b/rescue/Makefile.am @@ -0,0 +1,48 @@ +# libguestfs virt-rescue +# Copyright (C) 2009 Red Hat Inc. +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 2 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program; if not, write to the Free Software +# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + +EXTRA_DIST = \ + run-rescue-locally \ + virt-rescue.pl + +if HAVE_RESCUE + +man_MANS = virt-rescue.1 + +noinst_DATA = @top_builddir@/html/virt-rescue.1.html + +virt-rescue.1: virt-rescue.pl + $(POD2MAN) \ + --section 1 \ + -c "Virtualization Support" \ + --release "$(PACKAGE_NAME)-$(PACKAGE_VERSION)" \ + $< > $@ + +@top_builddir@/html/virt-rescue.1.html: virt-rescue.pl + mkdir -p @top_builddir@/html + cd @top_builddir@ && pod2html \ + --css 'pod.css' \ + --title 'virt-rescue, run a rescue shell on a virtual machine' \ + --htmldir html \ + --outfile html/virt-rescue.1.html \ + rescue/$< + +install-data-hook: + mkdir -p $(DESTDIR)$(bindir) + install -m 0755 virt-rescue.pl $(DESTDIR)$(bindir)/virt-rescue + +endif diff --git a/rescue/run-rescue-locally b/rescue/run-rescue-locally new file mode 100755 index 0000000..d814ed5 --- /dev/null +++ b/rescue/run-rescue-locally @@ -0,0 +1,53 @@ +#!/usr/bin/perl +# virt-rescue +# Copyright (C) 2009 Red Hat Inc. +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 2 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program; if not, write to the Free Software +# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + +# This script sets up the environment so you can run virt-rescue in +# place without needing to do 'make install' first. You can also run +# virt-rescue by creating a symlink to this script and putting it in +# your path. +# +# Use it like this: +# ./run-rescue-locally [usual virt-rescue args ...] + +use strict; +use warnings; + +use File::Basename qw(dirname); +use File::Spec; +use Cwd qw(abs_path); + +my $path = $0; + +# Follow symlinks until we get to the real file +while(-l $path) { + my $link = readlink($path); + if(File::Spec->file_name_is_absolute($link)) { + $path = $link; + } else { + $path = File::Spec->catfile(dirname($path), $link); + } +} + +# Get the absolute path of the parent directory +$path = abs_path(dirname($path).'/..'); + +$ENV{LD_LIBRARY_PATH} = $path.'/src/.libs'; +$ENV{LIBGUESTFS_PATH} = $path.'/appliance'; +$ENV{PERL5LIB} = $path.'/perl/blib/lib:'.$path.'/perl/blib/arch'; + +exec('perl', $path.'/rescue/virt-rescue.pl', @ARGV); diff --git a/rescue/virt-rescue.pl b/rescue/virt-rescue.pl new file mode 100755 index 0000000..a44940d --- /dev/null +++ b/rescue/virt-rescue.pl @@ -0,0 +1,169 @@ +#!/usr/bin/perl -w +# virt-rescue +# Copyright (C) 2009 Red Hat Inc. +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 2 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program; if not, write to the Free Software +# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + +use warnings; +use strict; + +use Sys::Guestfs; +use Sys::Guestfs::Lib qw(open_guest); +use Pod::Usage; +use Getopt::Long; +use Locale::TextDomain 'libguestfs'; + +=encoding utf8 + +=head1 NAME + +virt-rescue - Run a rescue shell on a virtual machine + +=head1 SYNOPSIS + + virt-rescue [--options] domname + + virt-rescue [--options] disk.img [disk.img ...] + +=head1 DESCRIPTION + +virt-rescue gives you a rescue shell and some simple recovery tools +which you can use on a virtual machine disk image. + +After running virt-rescue, what you see under C is the recovery +appliance. You must mount the virtual machine's filesystems by hand, +eg: + + # lvs + LV VG Attr LSize Origin Snap% Move Log Copy% Convert + lv_root vg_f11x64 -wi-a- 8.83G + lv_swap vg_f11x64 -wi-a- 992.00M + # mount /dev/vg_f11x64/lv_root /sysroot + # ls /sysroot + +B that the virtual machine must not be powered on when you use +this tool. Doing so will probably result in disk corruption in the +VM. However if you use the I<--ro> (read only) option, then you can +attach a shell to a running machine, but the results might be strange +or inconsistent. + +This tool is just designed for quick interactive hacking on a virtual +machine. For more structured access to a virtual machine disk image, +you should use L. To get a structured shell, use +L. + +=head1 OPTIONS + +=over 4 + +=cut + +my $help; + +=item B<--help> + +Display brief help. + +=cut + +my $version; + +=item B<--version> + +Display version number and exit. + +=cut + +my $uri; + +=item B<--connect URI> | B<-c URI> + +If using libvirt, connect to the given I. If omitted, then we +connect to the default libvirt hypervisor. + +If you specify guest block devices directly, then libvirt is not used +at all. + +=cut + +my $readonly; + +=item B<--ro> | B<-r> + +Open the image read-only. + +=back + +=cut + +GetOptions ("help|?" => \$help, + "version" => \$version, + "connect|c=s" => \$uri, + "ro|r" => \$readonly, + ) or pod2usage (2); +pod2usage (1) if $help; +if ($version) { + my $g = Sys::Guestfs->new (); + my %h = $g->version (); + print "$h{major}.$h{minor}.$h{release}$h{extra}\n"; + exit +} + +pod2usage (__"virt-rescue: no image or VM names rescue given") + if @ARGV == 0; + +my @args = (\@ARGV); +push @args, address => $uri if $uri; +push @args, rw => 1 unless $readonly; +my $g = open_guest (@args); + +$g->set_direct (1); +$g->set_append ("guestfs_rescue=1"); + +$g->launch (); + +exit 0; + +=head1 SEE ALSO + +L, +L, +L, +L, +L, +L, +L. + +=head1 AUTHOR + +Richard W.M. Jones L + +=head1 COPYRIGHT + +Copyright (C) 2009 Red Hat Inc. + +This program is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2 of the License, or +(at your option) any later version. + +This program is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with this program; if not, write to the Free Software +Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.