Provided by: libguestfs0_1.32.2-4ubuntu2_amd64 bug

НАЗВА

       guestfs-hacking - extending and contributing to libguestfs

ОПИС

       This manual page is for hackers who want to extend libguestfs itself.

   OVERVIEW OF THE SOURCE CODE
       Код libguestfs зберігається у сховищі github https://github.com/libguestfs/libguestfs

       Large amounts of boilerplate code in libguestfs (RPC, bindings, documentation) are
       generated.  This means that many source files will appear to be missing from a
       straightforward git checkout.  You have to run the generator ("./autogen.sh && make -C
       generator") in order to create those files.

       Libguestfs uses an autotools-based build system, with the main files being configure.ac
       and Makefile.am.  The generator subdirectory contains the generator, plus files describing
       the API.  The src subdirectory contains source for the library.  The appliance and daemon
       subdirectories contain the source for the code that builds the appliance, and the code
       that runs in the appliance respectively.  Other directories are covered in the section
       "SOURCE CODE SUBDIRECTORIES" below.

       Apart from the fact that all API entry points go via some generated code, the library is
       straightforward.  (In fact, even the generated code is designed to be readable, and should
       be read as ordinary code).  Some actions run entirely in the library, and are written as C
       functions in files under src.  Others are forwarded to the daemon where (after some
       generated RPC marshalling) they appear as C functions in files under daemon.

       To build from source, first read the "README" file.

   local* FILES
       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.

       By convention, I have a file called localconfigure which is a simple wrapper around
       autogen.sh containing local configure customizations that I need:

        . localenv
        ./autogen.sh \
            --with-default-backend=libvirt \
            --enable-gcc-warnings \
            --enable-gtk-doc \
            -C \
            "$@"

       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:

        # Use an alternate python binary.
        export PYTHON=python3
        # 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.

   ADDING A NEW API ACTION
       Because large amounts of boilerplate code in libguestfs are generated, this makes it easy
       to extend the libguestfs API.

       To add a new API action there are two changes:

       1.  You need to add a description of the call (name, parameters, return type, tests,
           documentation) to generator/actions.ml.

           There are two sorts of API action, depending on whether the call goes through to the
           daemon in the appliance, or is serviced entirely by the library (see "ARCHITECTURE" in
           guestfs-internals(3)).  "guestfs_sync" in guestfs(3) is an example of the former,
           since the sync is done in the appliance.  "guestfs_set_trace" in guestfs(3) is an
           example of the latter, since a trace flag is maintained in the handle and all tracing
           is done on the library side.

           Most new actions are of the first type, and get added to the "daemon_functions" list.
           Each function has a unique procedure number used in the RPC protocol which is assigned
           to that action when we publish libguestfs and cannot be reused.  Take the latest
           procedure number and increment it.

           For library-only actions of the second type, add to the "non_daemon_functions" list.
           Since these functions are serviced by the library and do not travel over the RPC
           mechanism to the daemon, these functions do not need a procedure number, and so the
           procedure number is set to "-1".

       2.  Implement the action (in C):

           For daemon actions, implement the function "do_<name>" in the "daemon/" directory.

           For library actions, implement the function "guestfs_impl_<name>" in the "src/"
           directory.

           In either case, use another function as an example of what to do.

       After making these changes, use "make" to compile.

       Note that you don't need to implement the RPC, language bindings, manual pages or anything
       else.  It's all automatically generated from the OCaml description.

   ADDING TESTS FOR AN API ACTION
       You can supply zero or as many tests as you want per API call.  The tests can either be
       added as part of the API description (generator/actions.ml), or in some rarer cases you
       may want to drop a script into "tests/*/".  Note that adding a script to "tests/*/" is
       slower, so if possible use the first method.

       The following describes the test environment used when you add an API test in actions.ml.

       The test environment has 4 block devices:

       /dev/sda 500MB
           Блоковий пристрій загального типу для тестування.

       /dev/sdb 500MB
           /dev/sdb1 is an ext2 filesystem used for testing filesystem write operations.

       /dev/sdc 10MB
           Used in a few tests where two block devices are needed.

       /dev/sdd
           ISO with fixed content (see images/test.iso).

       To be able to run the tests in a reasonable amount of time, the libguestfs appliance and
       block devices are reused between tests.  So don't try testing "guestfs_kill_subprocess" in
       guestfs(3) :-x

       Each test starts with an initial scenario, selected using one of the "Init*" expressions,
       described in generator/types.ml.  These initialize the disks mentioned above in a
       particular way as documented in types.ml.  You should not assume anything about the
       previous contents of other disks that are not initialized.

       You can add a prerequisite clause to any individual test.  This is a run-time check,
       which, if it fails, causes the test to be skipped.  Useful if testing a command which
       might not work on all variations of libguestfs builds.  A test that has prerequisite of
       "Always" means to run unconditionally.

       In addition, packagers can skip individual tests by setting environment variables before
       running "make check".

        SKIP_TEST_<CMD>_<NUM>=1

       eg: "SKIP_TEST_COMMAND_3=1" skips test #3 of "guestfs_command" in guestfs(3).

       або:

        SKIP_TEST_<CMD>=1

       eg: "SKIP_TEST_ZEROFREE=1" skips all "guestfs_zerofree" in guestfs(3) tests.

       Packagers can run only certain tests by setting for example:

        TEST_ONLY="vfs_type zerofree"

       See tests/c-api/tests.c for more details of how these environment variables work.

   ДІАГНОСТИКА НОВИХ ДІЙ API
       Test new actions work before submitting them.

       You can use guestfish to try out new commands.

       Debugging the daemon is a problem because it runs inside a minimal environment.  However
       you can fprintf messages in the daemon to stderr, and they will show up if you use
       "guestfish -v".

   ДОДАВАННЯ НОВОЇ ПРИВ’ЯЗКИ ДО МОВИ
       All language bindings must be generated by the generator (see the generator subdirectory).

       There is no documentation for this yet.  We suggest you look at an existing binding, eg.
       generator/ocaml.ml or generator/perl.ml.

   ADDING TESTS FOR LANGUAGE BINDINGS
       Language bindings should come with tests.  Previously testing of language bindings was
       rather ad-hoc, but we have been trying to formalize the set of tests that every language
       binding should use.

       Currently only the OCaml and Perl bindings actually implement the full set of tests, and
       the OCaml bindings are canonical, so you should emulate what the OCaml tests do.

       This is the numbering scheme used by the tests:

        - 000+ basic tests:

          010  load the library
          020  create
          030  create-flags
          040  create multiple handles
          050  test setting and getting config properties
          060  explicit close
          065  implicit close (in GC'd languages)
          070  optargs

        - 100  launch, create partitions and LVs and filesystems

        - 400+ events:

          410  close event
          420  log messages
          430  progress messages

        - 800+ regression tests (specific to the language)

        - 900+ any other custom tests for the language

       To save time when running the tests, only 100, 430, 800+, 900+ should launch the handle.

   FORMATTING CODE
       Our C source code generally adheres to some basic code-formatting conventions.  The
       existing code base is not totally consistent on this front, but we do prefer that
       contributed code be formatted similarly.  In short, use spaces-not-TABs for indentation,
       use 2 spaces for each indentation level, and other than that, follow the K&R style.

       If you use Emacs, add the following to one of one of your start-up files (e.g., ~/.emacs),
       to help ensure that you get indentation right:

        ;;; In libguestfs, indent with spaces everywhere (not TABs).
        ;;; Exceptions: Makefile and ChangeLog modes.
        (add-hook 'find-file-hook
            '(lambda () (if (and buffer-file-name
                                 (string-match "/libguestfs\\>"
                                     (buffer-file-name))
                                 (not (string-equal mode-name "Change Log"))
                                 (not (string-equal mode-name "Makefile")))
                            (setq indent-tabs-mode nil))))

        ;;; When editing C sources in libguestfs, use this style.
        (defun libguestfs-c-mode ()
          "C mode with adjusted defaults for use with libguestfs."
          (interactive)
          (c-set-style "K&R")
          (setq c-indent-level 2)
          (setq c-basic-offset 2))
        (add-hook 'c-mode-hook
                  '(lambda () (if (string-match "/libguestfs\\>"
                                      (buffer-file-name))
                                  (libguestfs-c-mode))))

   TESTING YOUR CHANGES
       Enable warnings when compiling (and fix any problems this finds):

        ./configure --enable-gcc-warnings

       Useful targets are:

       "make check"
           Runs the regular test suite.

           This is implemented using the regular automake "TESTS" target.  See the automake
           documentation for details.

       "make check-valgrind"
           Runs a subset of the test suite under valgrind.

           Any Makefile.am in the tree that has a "check-valgrind:" target will be run by this
           rule.

       "make check-valgrind-local-guests"
           Runs a subset of the test suite under valgrind using locally installed libvirt guests
           (read-only).

       "make check-direct"
           Runs all tests using default appliance back-end.  This only has any effect if a non-
           default backend was selected using "./configure --with-default-backend=..."

       "make check-valgrind-direct"
           Run a subset of the test suite under valgrind using the default appliance back-end.

       "make check-uml"
           Runs all tests using the User-Mode Linux backend.

           As there is no standard location for the User-Mode Linux kernel, you have to set
           "LIBGUESTFS_HV" to point to the kernel image, eg:

            make check-uml LIBGUESTFS_HV=~/d/linux-um/vmlinux

       "make check-valgrind-uml"
           Runs all tests using the User-Mode Linux backend, under valgrind.

           As above, you have to set "LIBGUESTFS_HV" to point to the kernel.

       "make check-with-upstream-qemu"
           Runs all tests using a local qemu binary.  It looks for the qemu binary in QEMUDIR
           (defaults to $HOME/d/qemu), but you can set this to another directory on the command
           line, eg:

            make check-with-upstream-qemu QEMUDIR=/usr/src/qemu

       "make check-with-upstream-libvirt"
           Runs all tests using a local libvirt.  This only has any effect if the libvirt backend
           was selected using "./configure --with-default-backend=libvirt"

           It looks for libvirt in LIBVIRTDIR (defaults to $HOME/d/libvirt), but you can set this
           to another directory on the command line, eg:

            make check-with-upstream-libvirt LIBVIRTDIR=/usr/src/libvirt

       "make check-slow"
           Runs some slow/long-running tests which are not run by default.

           Any Makefile.am in the tree that has a "check-slow:" target will be run by this rule.

       "make check-all"
           Equivalent to running all "make check*" rules.

       "make check-release"
           Runs a subset of "make check*" rules that are required to pass before a tarball can be
           released.  Currently this is:

           ·   check

           ·   check-valgrind

           ·   check-direct

           ·   check-valgrind-direct

           ·   check-slow

       "make installcheck"
           Run "make check" on the installed copy of libguestfs.

           The version of installed libguestfs being tested, and the version of the libguestfs
           source tree must be the same.

           Команди:

            ./autogen.sh
            make clean ||:
            make
            make installcheck

   DAEMON CUSTOM PRINTF FORMATTERS
       In the daemon code we have created custom printf formatters %Q and %R, which are used to
       do shell quoting.

       %Q  Simple shell quoted string.  Any spaces or other shell characters are escaped for you.

       %R  Same as %Q except the string is treated as a path which is prefixed by the sysroot.

       Приклад:

        asprintf (&cmd, "cat %R", path);

       would produce "cat /sysroot/some\ path\ with\ spaces"

       Note: Do not use these when you are passing parameters to the "command{,r,v,rv}()"
       functions.  These parameters do NOT need to be quoted because they are not passed via the
       shell (instead, straight to exec).  You probably want to use the "sysroot_path()" function
       however.

   SUBMITTING YOUR NEW API ACTIONS
       Submit patches to the mailing list: http://www.redhat.com/mailman/listinfo/libguestfs and
       CC to rjones@redhat.com.

   INTERNATIONALIZATION (I18N) SUPPORT
       We support i18n (gettext anyhow) in the library.

       However many messages come from the daemon, and we don't translate those at the moment.
       One reason is that the appliance generally has all locale files removed from it, because
       they take up a lot of space.  So we'd have to readd some of those, as well as copying our
       PO files into the appliance.

       Debugging messages are never translated, since they are intended for the programmers.

   SOURCE CODE SUBDIRECTORIES
       align
           Програма virt-alignment-scan(1) та документація до неї.

       appliance
           The libguestfs appliance, build scripts and so on.

       bash
           Bash tab-completion scripts.

       build-aux
           Various build scripts used by autotools.

       builder
           Програма virt-builder(1) та документація до неї.

       cat The virt-cat(1), virt-filesystems(1), virt-log(1) and virt-ls(1) commands and
           documentation.

       contrib
           Outside contributions, experimental parts.

       customize
           Програма virt-customize(1) та документація до неї.

       daemon
           The daemon that runs inside the libguestfs appliance and carries out actions.

       df  Програма virt-df(1) та документація до неї.

       dib Програма virt-dib(1) та документація до неї.

       diff
           Програма virt-diff(1) та документація до неї.

       doc Miscellaneous manual pages.

       edit
           Програма virt-edit(1) та документація до неї.

       examples
           Код прикладів використання програмного інтерфейсу мовою C.

       fish
           guestfish(1), the command-line shell, and various shell scripts built on top such as
           virt-copy-in(1), virt-copy-out(1), virt-tar-in(1), virt-tar-out(1).

       format
           Програма virt-format(1) та документація до неї.

       fuse
           guestmount(1), FUSE (userspace filesystem) built on top of libguestfs.

       generator
           The crucially important generator, used to automatically generate large amounts of
           boilerplate C code for things like RPC and bindings.

       get-kernel
           Програма virt-get-kernel(1) та документація до неї.

       gnulib
           Gnulib is used as a portability library.  A copy of gnulib is included under here.

       inspector
           virt-inspector(1), the virtual machine image inspector.

       logo
           Logo used on the website.  The fish is called Arthur by the way.

       m4  M4 macros used by autoconf.

       make-fs
           Програма virt-make-fs(1) та документація до неї.

       mllib
           Various libraries and common code used by virt-resize(1) and the other tools which are
           written in OCaml.

       p2v virt-p2v(1) command, documentation and scripts for building the virt-p2v ISO or disk
           image.

       po  Переклади простих рядків gettext.

       po-docs
           The build infrastructure and PO files for translations of manpages and POD files.
           Eventually this will be combined with the po directory, but that is rather
           complicated.

       rescue
           Програма virt-rescue(1) та документація до неї.

       resize
           Програма virt-resize(1) та документація до неї.

       sparsify
           Програма virt-sparsify(1) та документація до неї.

       src Початковий код бібліотеки мовою C.

       sysprep
           Програма virt-sysprep(1) та документація до неї.

       tests
           Тести.

       test-data
           Files and other test data used by the tests.

       test-tool
           Test tool for end users to test if their qemu/kernel combination will work with
           libguestfs.

       tmp Used for temporary files when running the tests (instead of /tmp etc).  The reason is
           so that you can run multiple parallel tests of libguestfs without having one set of
           tests overwriting the appliance created by another.

       tools
           Command line tools written in Perl (virt-win-reg(1) and many others).

       v2v Програма virt-v2v(1) та документація до неї.

       website
           The http://libguestfs.org website files.

       csharp
       erlang
       gobject
       golang
       haskell
       java
       lua
       ocaml
       php
       perl
       python
       ruby
           Прив’язки до мов програмування.

   СТВОРЕННЯ СТАБІЛЬНОГО ВИПУСКУ
       When we make a stable release, there are several steps documented here.  See "LIBGUESTFS
       VERSION NUMBERS" in guestfs(3) for general information about the stable branch policy.

       ·   Check "make && make check" works on at least Fedora, Debian and Ubuntu.

       ·   Check "./configure --without-libvirt" works.

       ·   Finalize guestfs-release-notes.pod

       ·   Push and pull from Zanata.

           Віддайте команду:

            zanata push

           to push the latest POT files to Zanata.  Then run:

            ./zanata-pull.sh

           which is a wrapper to pull the latest translated *.po files.

       ·   Consider updating gnulib to latest upstream version.

       ·   Create new stable and development directories under http://libguestfs.org/download.

       ·   Edit website/index.html.in.

       ·   Set the version (in configure.ac) to the new stable version, ie. 1.XX.0, and commit
           it:

            ./localconfigure
            make distclean -k
            ./localconfigure
            make && make dist
            make maintainer-commit
            make maintainer-tag

       ·   Create the stable branch in git:

            git branch stable-1.XX
            git push origin stable-1.XX

       ·   Do a full release of the stable branch.

       ·   Set the version to the next development version and commit that.  Optionally do a full
           release of the development branch.

ТАКОЖ ПЕРЕГЛЯНЬТЕ

       guestfs(3), guestfs-examples(3), guestfs-internals(3), guestfs-performance(1),
       guestfs-release-notes(1), guestfs-testing(1), libguestfs-test-tool(1),
       libguestfs-make-fixed-appliance(1), http://libguestfs.org/.

АВТОРИ

       Richard W.M. Jones ("rjones at redhat dot com")

АВТОРСЬКІ ПРАВА

       Copyright (C) 2009-2016 Red Hat Inc.

LICENSE

BUGS

       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:

       ·   The version of libguestfs.

       ·   Where you got libguestfs (eg. which Linux distro, compiled from source, etc)

       ·   Describe the bug accurately and give a way to reproduce it.

       ·   Run libguestfs-test-tool(1) and paste the complete, unedited output into the bug
           report.