| guestfs-building(1) | Virtualization Support | guestfs-building(1) |
guestfs-building - How to build libguestfs from source
This manual page describes how to build libguestfs from source.
The main steps are:
On Fedora, use dnf(8) to install all the requirements:
dnf builddep libguestfs dnf install autoconf automake libtool gettext-devel
On systems still using yum(8), do:
yum-builddep libguestfs yum install autoconf automake libtool gettext-devel
Use APT to install all the requirements:
apt-get build-dep libguestfs apt-get install autoconf automake libtool-bin gettext
If that command doesn't work, take a look at the Debian source package http://packages.debian.org/source/libguestfs, at the list of "build-depends" and "build-depends-indep", and install everything listed there.
Note: If you build libguestfs followed by installing appliance packages, the build will not pick them up automatically, even if you do "make clean". You have to do this command to clean the old supermin appliance and force a new one to be prepared:
make -C appliance clean-supermin-appliance
The "rpcgen" tool is optional, except if you want to compile from git and/or patch libguestfs with new APIs.
You will need to install additional dependencies "autoconf", "automake", "gettext", OCaml findlib and po4a when building from git.
git clone https://github.com/libguestfs/libguestfs cd libguestfs git submodule update --init CFLAGS=-fPIC ./autogen.sh make
Tarballs are downloaded from http://download.libguestfs.org/. Stable tarballs are signed with the GnuPG key for "rich@annexia.org", see https://pgp.mit.edu/pks/lookup?op=vindex&search=0x91738F73E1B768A0. The fingerprint is "F777 4FB1 AD07 4A7E 8C87 67EA 9173 8F73 E1B7 68A0".
Download and unpack the tarball.
cd libguestfs-1.xx.yy ./configure make
DO NOT run the tests as root! Libguestfs can be built and tested as non-root. Running the tests as root could even be dangerous, don't do it.
To sanity check that the build worked, do:
make quickcheck
To run the basic tests, do:
make check
There are many more tests you can run. See guestfs-hacking(1) for details.
DO NOT use "make install"! You'll end up with conflicting versions of libguestfs installed, and this causes constant headaches for users. See the next section for how to use the ./run script instead.
Distro packagers can use:
make INSTALLDIRS=vendor DESTDIR=[temp-build-dir] install
You can run guestfish(1), guestmount(1) and the virt tools without needing to install them by using the ./run script in the top directory. This script works by setting several environment variables.
For example:
./run guestfish [usual guestfish args ...] ./run virt-inspector [usual virt-inspector args ...]
The ./run script adds every libguestfs binary to the $PATH, so the above examples run guestfish and virt-inspector from the build directory (not the globally installed guestfish if there is one).
You can use the script from any directory. If you wanted to run your own libguestfs-using program, then the following command will also work:
/path/to/libguestfs/run ./my_program [...]
You can also run the C programs under valgrind like this:
./run valgrind [valgrind opts...] virt-cat [virt-cat opts...]
or under gdb:
./run gdb --args virt-cat [virt-cat opts...]
This also works with sudo (eg. if you need root access for libvirt or to access a block device):
sudo ./run virt-cat -d LinuxGuest /etc/passwd
To set environment variables, you can either do:
LIBGUESTFS_HV=/my/qemu ./run guestfish
or:
./run env LIBGUESTFS_HV=/my/qemu guestfish
Files in the top source directory that begin with the prefix local* are ignored by git. These files can contain local configuration or scripts that you need to build libguestfs.
I have a file called localconfigure which is a simple wrapper around autogen.sh containing local configure customizations that I need. It looks like this:
. localenv
./autogen.sh \
-C \
--enable-werror \
"$@"
So I can use this to build libguestfs:
./localconfigure && make
If there is a file in the top build directory called localenv, then it will be sourced by "make". This file can contain any local environment variables needed, eg. for skipping tests:
# Skip this test, it is broken. export SKIP_TEST_BTRFS_FSCK=1
Note that localenv is included by the top Makefile (so it’s a Makefile fragment). But if it is also sourced by your localconfigure script then it is used as a shell script.
There are many "./configure" options. Use:
./configure --help
to list them all. This section covers some of the more important ones.
Note that disabling OCaml (bindings) or Perl will have the knock-on effect of disabling parts of the test suite and some tools.
OCaml is required to build libguestfs and this requirement cannot be removed. Using --disable-ocaml only disables the bindings and OCaml tools.
Fedora and Red Hat Enterprise Linux (RHEL) ≥ 7 use this flag to change the default backend to "libvirt", because (especially in RHEL) the policy is not to allow any program to run qemu except via libvirt.
Note that despite this setting, all backends are built into libguestfs, and you can override the backend at runtime by setting the $LIBGUESTFS_BACKEND environment variable (or using API methods).
However if you can building or packaging libguestfs on a new distro then you can use --with-distro to specify that the distro is similar to an existing one (eg. --with-distro=REDHAT if the distro is a new Red Hat or CentOS derivative).
Note that if your distro is completely new then it may still require upstream modifications.
For custom and/or local builds, this can be set to "local" to indicate this is not a distro build.
The most common use for this is to build the appliance using an alternate repository (instead of using the installed yum/dnf/apt/etc configuration to find and download packages). You might need to use this if you want to build libguestfs without having a network connection. Examples of using this can be found in the Fedora "libguestfs.spec" file (see "BUILDING A PACKAGE FOR FEDORA" below for resources).
A common problem is with broken or incompatible qemu releases.
Different versions of qemu have problems booting the appliance for different reasons. This varies between versions of qemu, and Linux distributions which add their own patches.
If you find a problem, you could try using your own qemu built from source (qemu is very easy to build from source), with a "qemu wrapper". See "QEMU WRAPPERS" in guestfs(3).
By default the configure script will look for qemu-kvm (KVM support). KVM is much faster than using plain qemu.
You may also need to enable KVM support for non-root users, by following these instructions: http://www.linux-kvm.org/page/FAQ#How_can_I_use_kvm_with_a_non-privileged_user.3F
On some systems, this will work too:
chmod 0666 /dev/kvm
On some systems, the chmod will not survive a reboot, and you will need to make edits to the udev configuration.
export CC=clang ./configure make
To understand what the libguestfs appliance means, see guestfs-internals(1).
If you are using non-Linux, or a Linux distribution that does not have supermin(1) support, or simply if you don't want to build your own libguestfs appliance, then you can use one of the prebuilt binary appliances that we supply: http://libguestfs.org/download/binaries/appliance
Build libguestfs like this:
./configure --disable-appliance --disable-daemon make
Set $LIBGUESTFS_PATH to the path where you unpacked the appliance tarball, eg:
export LIBGUESTFS_PATH=/usr/local/lib/guestfs/appliance
and run the libguestfs programs and virt tools in the normal way, eg. using the ./run script (see above).
The Fedora spec file is stored under: http://pkgs.fedoraproject.org/cgit/rpms/libguestfs.git/
Libguestfs is built in Fedora using the ordinary Fedora build system (Koji).
Red Hat Enterprise Linux (RHEL) builds of libguestfs are heavily patched. There are broadly two types of patches we apply:
The patches we apply to RHEL releases are available publically in the upstream git repository, in a branch called "rhel-x.y"
For example, the RHEL 7.3 patches are available here: https://github.com/libguestfs/libguestfs/commits/rhel-7.3
The sources and spec files for RHEL versions of libguestfs are available on https://git.centos.org/project/rpms, and see also https://wiki.centos.org/Sources.
guestfs(3), guestfs-examples(3), guestfs-hacking(1), guestfs-internals(1), guestfs-performance(1), guestfs-release-notes(1), guestfs-testing(1), libguestfs-test-tool(1), libguestfs-make-fixed-appliance(1), http://libguestfs.org/.
Richard W.M. Jones ("rjones at redhat dot com")
Copyright (C) 2009-2020 Red Hat Inc.
This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
This library 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 Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
To get a list of bugs against libguestfs, use this link: https://bugzilla.redhat.com/buglist.cgi?component=libguestfs&product=Virtualization+Tools
To report a new bug against libguestfs, use this link: https://bugzilla.redhat.com/enter_bug.cgi?component=libguestfs&product=Virtualization+Tools
When reporting a bug, please supply:
| 2021-01-05 | libguestfs-1.44.0 |