diff options
| -rw-r--r-- | HACKING | 260 | ||||
| -rw-r--r-- | Makefile.am | 2 | ||||
| -rw-r--r-- | daemon/daemon.h | 4 | ||||
| -rw-r--r-- | daemon/guestfsd.c | 3 | ||||
| -rw-r--r-- | generator/generator_main.ml | 6 | ||||
| -rw-r--r-- | generator/generator_types.ml | 2 | ||||
| -rwxr-xr-x | src/api-support/update-from-tarballs.sh | 2 | ||||
| -rw-r--r-- | src/guestfs.pod | 342 |
8 files changed, 354 insertions, 267 deletions
@@ -1,258 +1,2 @@ -PLEASE LOOK AT THE TOP OF EACH FILE BEFORE EDITING TO SEE WHETHER IT -IS AUTOMATICALLY GENERATED OR NOT. - -Adding a new action ----------------------------------------------------------------------- - -All action functions are generated automatically, so there are only -two files you need to edit: - -(1) generator/generator_actions.ml: Add your new action, parameters, -description, etc. to the big list at the top of this file. - -(2) Edit/create a C file in daemon/ subdirectory which implements your -'do_action' function. Take a look at one of the numerous examples -there. - -Formatting ----------------------------------------------------------------------- - -Try to use GNU / Emacs default formatting, following the convention -used elsewhere in the source. - -Please make sure that the code compiles without warnings. - -Please test any changes. - -Useful targets: - make syntax-check Checks the syntax of the C code. - make check Runs the test suite. - -Enable warnings, and fix any you find: - ./configure --enable-gcc-warnings - -Code indentation ----------------------------------------------------------------------- -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)))) - -Directories ----------------------------------------------------------------------- - -appliance/ - The qemu appliance, build scripts and so on. - -capitests/ - Automated tests of the C API. See "Tests" below. - -cat/ - The 'virt-cat', 'virt-filesystems' and 'virt-ls' commands and - documentation. - -contrib/ - Outside contributions, experimental parts. - -csharp/ - Experimental C# bindings. - -daemon/ - The daemon that runs inside the guest and carries out actions. - -df/ - 'virt-df' command and documentation. - -examples/ - The examples. - -fish/ - Guestfish (the command-line program / shell) - -fuse/ - 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. - -haskell/ - Haskell bindings. - -hivex/ [removed in 1.0.85] - This used to contain the hivex library for reading and - writing Windows Registry binary hive files. This is now - available as a separate upstream project. - -images/ - Some guest images to test against. These are gzipped to save - space. You have to unzip them before use. - - Also contains some files used by the test suite. - -inspector/ - Virtual machine image inspector (virt-inspector). - -java/ - Java bindings. - -m4/ - M4 macros used by autoconf. - -ocaml/ - OCaml bindings. - -php/ - PHP bindings. - -po/ - Translations of simple gettext strings. For translations of - longer documents, see po-docs/. - -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. - -perl/ - Perl bindings. - -python/ - Python bindings. - -regressions/ - Regression tests. - -rescue/ - 'virt-rescue' command and documentation. - -ruby/ - Ruby bindings. - -tools/ - Command line tools written in Perl (virt-resize and more). - -src/ - Source code to the C library. - -test-tool/ - Interactive qemu/kernel test tool. - -Tests ----------------------------------------------------------------------- - -You can supply zero or as many tests as you want per API call. - -The test environment has 4 block devices: - /dev/sda 500MB General block device for testing. - /dev/sdb 50MB /dev/sdb1 is an ext2 filesystem used for testing - filesystem write operations. - /dev/sdc 10MB Used in a few tests where 2 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 -virtual machine and block devices are reused between tests. So don't -try testing kill_subprocess :-x Between each test we blockdev-setrw, -umount-all, lvm-remove-all. - -Each test starts with an initial scenario, selected using one of the -'Init*' expressions, described in generator/generator_types.ml. These -initialize the disks in a particular way as described. 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' is run -unconditionally. - -In addition, packagers can skip individual tests by setting the -environment variables: eg: - - SKIP_TEST_<CMD>_<NUM>=1 SKIP_TEST_COMMAND_3=1 (skips test #3 of command) - SKIP_TEST_<CMD>=1 SKIP_TEST_ZEROFREE=1 (skips all zerofree tests) - -and packagers can run only certain tests by setting eg: - - TEST_ONLY="vfs_type zerofree" - -See capitests/tests.c for more details of how these environment -variables work. - -Debugging ----------------------------------------------------------------------- - -It's a good idea to use guestfish to try out new commands. - -Debugging the daemon is a problem because it runs inside a minimal -qemu environment. However you can print messages from the daemon, and -they will show up if you use 'guestfish -v'. - -Patches ----------------------------------------------------------------------- - -Submit patches to the mailing list: -http://www.redhat.com/mailman/listinfo/libguestfs -and CC to rjones@redhat.com - -I18N ----------------------------------------------------------------------- - -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. - -Extended printf ----------------------------------------------------------------------- - -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. - -eg. - -asprintf (&cmd, "cat %R", path); -==> "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. +The contents of this page have moved to the section "EXTENDING LIBGUESTFS" +in the guestfs(3) man page. diff --git a/Makefile.am b/Makefile.am index 0df92d40..66ec0c68 100644 --- a/Makefile.am +++ b/Makefile.am @@ -128,7 +128,7 @@ HTMLFILES = \ html/recipes.html \ html/pod.css html/recipes.css -TEXTFILES = BUGS HACKING README RELEASE-NOTES ROADMAP TODO +TEXTFILES = BUGS README RELEASE-NOTES ROADMAP TODO WEBSITEDIR = $(HOME)/d/redhat/websites/libguestfs diff --git a/daemon/daemon.h b/daemon/daemon.h index 1e589100..6845e1b3 100644 --- a/daemon/daemon.h +++ b/daemon/daemon.h @@ -81,8 +81,8 @@ extern int prog_exists (const char *prog); extern void udev_settle (void); -/* This just stops gcc from giving a warning about our custom - * printf formatters %Q and %R. See HACKING file for more +/* This just stops gcc from giving a warning about our custom printf + * formatters %Q and %R. See guestfs(3)/EXTENDING LIBGUESTFS for more * info about these. */ static inline int diff --git a/daemon/guestfsd.c b/daemon/guestfsd.c index e398b7d8..16b900f0 100644 --- a/daemon/guestfsd.c +++ b/daemon/guestfsd.c @@ -974,7 +974,8 @@ trim (char *str) } /* printf helper function so we can use %Q ("quoted") and %R to print - * shell-quoted strings. See HACKING file for more details. + * shell-quoted strings. See guestfs(3)/EXTENDING LIBGUESTFS for more + * details. */ static int print_shell_quote (FILE *stream, diff --git a/generator/generator_main.ml b/generator/generator_main.ml index 4ef9ba51..f3d3340a 100644 --- a/generator/generator_main.ml +++ b/generator/generator_main.ml @@ -50,7 +50,7 @@ let perror msg = function (* Main program. *) let () = let lock_fd = - try openfile "HACKING" [O_RDWR] 0 + try openfile "BUGS" [O_RDWR] 0 with | Unix_error (ENOENT, _, _) -> eprintf "\ @@ -60,7 +60,7 @@ Run it from the top source directory using the command "; exit 1 | exn -> - perror "open: HACKING" exn; + perror "open: BUGS" exn; exit 1 in (* Acquire a lock so parallel builds won't try to run the generator @@ -70,7 +70,7 @@ Run it from the top source directory using the command *) (try lockf lock_fd F_LOCK 1 with exn -> - perror "lock: HACKING" exn; + perror "lock: BUGS" exn; exit 1); (* Read the API versions file. *) diff --git a/generator/generator_types.ml b/generator/generator_types.ml index 369a49a3..b6c27309 100644 --- a/generator/generator_types.ml +++ b/generator/generator_types.ml @@ -218,7 +218,7 @@ and fish_output_t = | FishOutputOctal (* for int return, print in octal *) | FishOutputHexadecimal (* for int return, print in hex *) -(* See section "Tests" in HACKING file. *) +(* See guestfs(3)/EXTENDING LIBGUESTFS. *) type tests = (test_init * test_prereq * test) list and test = (* Run the command sequence and just expect nothing to fail. *) diff --git a/src/api-support/update-from-tarballs.sh b/src/api-support/update-from-tarballs.sh index 59f78d92..85798253 100755 --- a/src/api-support/update-from-tarballs.sh +++ b/src/api-support/update-from-tarballs.sh @@ -16,7 +16,7 @@ # along with this program; if not, write to the Free Software # Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. -if [ ! -f HACKING ]; then +if [ ! -f BUGS ]; then echo "You should run this script from the top source directory." exit 1 fi diff --git a/src/guestfs.pod b/src/guestfs.pod index 7d2f91c8..93f31e61 100644 --- a/src/guestfs.pod +++ b/src/guestfs.pod @@ -2088,6 +2088,348 @@ dot-oh release won't necessarily be so stable at this point, but by backporting fixes from development, that branch will stabilize over time. +=head1 EXTENDING LIBGUESTFS + +=head2 ADDING A NEW API ACTION + +Large amounts of boilerplate code in libguestfs (RPC, bindings, +documentation) are generated, and this makes it easy to extend the +libguestfs API. + +To add a new API action there are two changes: + +=over 4 + +=item 1. + +You need to add a description of the call (name, parameters, return +type, tests, documentation) to C<generator/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 L</ARCHITECTURE> above). L</guestfs_sync> is an example +of the former, since the sync is done in the appliance. +L</guestfs_set_trace> 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 +C<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 +C<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 C<-1>. + +=item 2. + +Implement the action (in C): + +For daemon actions, implement the function C<do_E<lt>nameE<gt>> in the +C<daemon/> directory. + +For library actions, implement the function C<guestfs__E<lt>nameE<gt>> +(note: double underscore) in the C<src/> directory. + +In either case, use another function as an example of what to do. + +=back + +After making these changes, use C<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. + +=head2 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 +(C<generator/generator_actions.ml>), or in some rarer cases you may +want to drop a script into C<regressions/>. Note that adding a script +to C<regressions/> is slower, so if possible use the first method. + +The following describes the test environment used when you add an API +test in C<generator_actions.ml>. + +The test environment has 4 block devices: + +=over 4 + +=item C</dev/sda> 500MB + +General block device for testing. + +=item C</dev/sdb> 50MB + +C</dev/sdb1> is an ext2 filesystem used for testing +filesystem write operations. + +=item C</dev/sdc> 10MB + +Used in a few tests where two block devices are needed. + +=item C</dev/sdd> + +ISO with fixed content (see C<images/test.iso>). + +=back + +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 L</guestfs_kill_subprocess> :-x + +Each test starts with an initial scenario, selected using one of the +C<Init*> expressions, described in C<generator/generator_types.ml>. +These initialize the disks mentioned above in a particular way as +documented in C<generator_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 C<Always> means to +run unconditionally. + +In addition, packagers can skip individual tests by setting +environment variables before running C<make check>. + + SKIP_TEST_<CMD>_<NUM>=1 + +eg: C<SKIP_TEST_COMMAND_3=1> skips test #3 of L</guestfs_command>. + +or: + + SKIP_TEST_<CMD>=1 + +eg: C<SKIP_TEST_ZEROFREE=1> skips all L</guestfs_zerofree> tests. + +Packagers can run only certain tests by setting for example: + + TEST_ONLY="vfs_type zerofree" + +See C<capitests/tests.c> for more details of how these environment +variables work. + +=head2 DEBUGGING NEW API ACTIONS + +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 C<guestfish -v>. + +=head2 FORMATTING CODE AND OTHER CONVENTIONS + +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)))) + +Enable warnings when compiling (and fix any problems this +finds): + + ./configure --enable-gcc-warnings + +Useful targets are: + + make syntax-check # checks the syntax of the C code + make check # runs the test suite + +=head2 DAEMON CUSTOM PRINTF FORMATTERS + +In the daemon code we have created custom printf formatters C<%Q> and +C<%R>, which are used to do shell quoting. + +=over 4 + +=item %Q + +Simple shell quoted string. Any spaces or other shell characters are +escaped for you. + +=item %R + +Same as C<%Q> except the string is treated as a path which is prefixed +by the sysroot. + +=back + +For example: + + asprintf (&cmd, "cat %R", path); + +would produce C<cat /sysroot/some\ path\ with\ spaces> + +I<Note:> Do I<not> use these when you are passing parameters to the +C<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 C<sysroot_path()> function +however. + +=head2 SUBMITTING YOUR NEW API ACTIONS + +Submit patches to the mailing list: +L<http://www.redhat.com/mailman/listinfo/libguestfs> +and CC to L<rjones@redhat.com>. + +=head2 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. + +=head2 SOURCE CODE SUBDIRECTORIES + +=over 4 + +=item C<appliance> + +The libguestfs appliance, build scripts and so on. + +=item C<capitests> + +Automated tests of the C API. + +=item C<cat> + +The L<virt-cat(1)>, L<virt-filesystems(1)> and L<virt-ls(1)> commands +and documentation. + +=item C<contrib> + +Outside contributions, experimental parts. + +=item C<daemon> + +The daemon that runs inside the libguestfs appliance and carries out +actions. + +=item C<df> + +L<virt-df(1)> command and documentation. + +=item C<examples> + +C API example code. + +=item C<fish> + +L<guestfish(1)>, the command-line shell. + +=item C<fuse> + +L<guestmount(1)>, FUSE (userspace filesystem) built on top of libguestfs. + +=item C<generator> + +The crucially important generator, used to automatically generate +large amounts of boilerplate C code for things like RPC and bindings. + +=item C<images> + +Files used by the test suite. + +Some "phony" guest images which we test against. + +=item C<inspector> + +L<virt-inspector(1)>, the virtual machine image inspector. + +=item C<m4> + +M4 macros used by autoconf. + +=item C<po> + +Translations of simple gettext strings. + +=item C<po-docs> + +The build infrastructure and PO files for translations of manpages and +POD files. Eventually this will be combined with the C<po> directory, +but that is rather complicated. + +=item C<regressions> + +Regression tests. + +=item C<rescue> + +L<virt-rescue(1)> command and documentation. + +=item C<src> + +Source code to the C library. + +=item C<tools> + +Command line tools written in Perl (L<virt-resize(1)> and many others). + +=item C<test-tool> + +Test tool for end users to test if their qemu/kernel combination +will work with libguestfs. + +=item C<csharp> + +=item C<haskell> + +=item C<java> + +=item C<ocaml> + +=item C<php> + +=item C<perl> + +=item C<python> + +=item C<ruby> + +Language bindings. + +=back + =head1 ENVIRONMENT VARIABLES =over 4 |