[Libguestfs] [PATCH v1 NOT TO BE APPLIED] New tool: virt-v2v.

This is a rewrite of the original virt-v2v tool. The original was written by Matt Booth et al in Perl between 2009 and 2013. --- .gitignore | 5 ++ Makefile.am | 6 +- configure.ac | 3 +- fish/guestfish.pod | 1 + po/POTFILES | 1 + po/POTFILES-ml | 6 ++ src/guestfs.pod | 5 ++ v2v/Makefile.am | 167 ++++++++++++++++++++++++++++++++++ v2v/cmdline.ml | 141 +++++++++++++++++++++++++++++ v2v/source_libvirt.ml | 110 +++++++++++++++++++++++ v2v/source_libvirt.mli | 27 ++++++ v2v/types.ml | 35 ++++++++ v2v/types.mli | 38 ++++++++ v2v/utils.ml | 31 +++++++ v2v/v2v.ml | 200 +++++++++++++++++++++++++++++++++++++++++ v2v/virt-v2v.pod | 204 +++++++++++++++++++++++++++++++++++++++++ v2v/xml-c.c | 240 +++++++++++++++++++++++++++++++++++++++++++++++++ v2v/xml.ml | 50 +++++++++++ v2v/xml.mli | 57 ++++++++++++ 19 files changed, 1324 insertions(+), 3 deletions(-) create mode 100644 v2v/Makefile.am create mode 100644 v2v/cmdline.ml create mode 100644 v2v/source_libvirt.ml create mode 100644 v2v/source_libvirt.mli create mode 100644 v2v/types.ml create mode 100644 v2v/types.mli create mode 100644 v2v/utils.ml create mode 100644 v2v/v2v.ml create mode 100644 v2v/virt-v2v.pod create mode 100644 v2v/xml-c.c create mode 100644 v2v/xml.ml create mode 100644 v2v/xml.mli diff --git a/.gitignore b/.gitignore index dc8aaf8..9032597 100644 --- a/.gitignore +++ b/.gitignore @@ -256,6 +256,7 @@ Makefile.in /html/virt-tar.1.html /html/virt-tar-in.1.html /html/virt-tar-out.1.html +/html/virt-v2v.1.html /html/virt-win-reg.1.html /inspector/actual-*.xml /inspector/stamp-virt-inspector.pod @@ -526,3 +527,7 @@ Makefile.in /test-tool/libguestfs-test-tool-helper /test-tool/stamp-libguestfs-test-tool.pod /tools/virt-*.1 +/v2v/.depend +/v2v/stamp-virt-v2v.pod +/v2v/virt-v2v +/v2v/virt-v2v.1 diff --git a/Makefile.am b/Makefile.am index b135d65..3102e0b 100644 --- a/Makefile.am +++ b/Makefile.am @@ -132,7 +132,8 @@ SUBDIRS += \ builder builder/website \ resize \ sparsify \ - sysprep + sysprep \ + v2v endif # Perl tools. @@ -257,6 +258,7 @@ HTMLFILES = \ html/virt-tar.1.html \ html/virt-tar-in.1.html \ html/virt-tar-out.1.html \ + html/virt-v2v.1.html \ html/virt-win-reg.1.html HTMLSUPPORTFILES = \ @@ -319,7 +321,7 @@ all-local: grep -v -E '^python/utils.c$$' | \ LC_ALL=C sort > po/POTFILES cd $(srcdir); \ - find builder customize mllib resize sparsify sysprep -name '*.ml' | \ + find builder customize mllib resize sparsify sysprep v2v -name '*.ml' | \ LC_ALL=C sort > po/POTFILES-ml # Manual pages in top level directory. diff --git a/configure.ac b/configure.ac index 70d5afc..e70a730 100644 --- a/configure.ac +++ b/configure.ac @@ -1709,7 +1709,8 @@ AC_CONFIG_FILES([Makefile tests/tmpdirs/Makefile tests/xfs/Makefile tests/xml/Makefile - tools/Makefile]) + tools/Makefile + v2v/Makefile]) AC_OUTPUT dnl Produce summary. diff --git a/fish/guestfish.pod b/fish/guestfish.pod index 25279fb..5cf6ebc 100644 --- a/fish/guestfish.pod +++ b/fish/guestfish.pod @@ -1624,6 +1624,7 @@ L<virt-sysprep(1)>, L<virt-tar(1)>, L<virt-tar-in(1)>, L<virt-tar-out(1)>, +L<virt-v2v(1)>, L<virt-win-reg(1)>, L<libguestfs-tools.conf(5)>, L<display(1)>, diff --git a/po/POTFILES b/po/POTFILES index 0fac8fe..4d42dfd 100644 --- a/po/POTFILES +++ b/po/POTFILES @@ -318,3 +318,4 @@ src/test-utils.c src/tmpdirs.c src/utils.c test-tool/test-tool.c +v2v/xml-c.c diff --git a/po/POTFILES-ml b/po/POTFILES-ml index 4dce0e5..d04cca9 100644 --- a/po/POTFILES-ml +++ b/po/POTFILES-ml @@ -80,3 +80,9 @@ sysprep/sysprep_operation_udev_persistent_net.ml sysprep/sysprep_operation_user_account.ml sysprep/sysprep_operation_utmp.ml sysprep/sysprep_operation_yum_uuid.ml +v2v/cmdline.ml +v2v/source_libvirt.ml +v2v/types.ml +v2v/utils.ml +v2v/v2v.ml +v2v/xml.ml diff --git a/src/guestfs.pod b/src/guestfs.pod index 0f54625..f634442 100644 --- a/src/guestfs.pod +++ b/src/guestfs.pod @@ -4396,6 +4396,10 @@ created by another. Command line tools written in Perl (L<virt-win-reg(1)> and many others). +=item C<v2v> + +L<virt-v2v(1)> command and documentation. + =item C<csharp> =item C<erlang> @@ -4749,6 +4753,7 @@ L<virt-sysprep(1)>, L<virt-tar(1)>, L<virt-tar-in(1)>, L<virt-tar-out(1)>, +L<virt-v2v(1)>, L<virt-win-reg(1)>, L<guestfs-faq(1)>, L<guestfs-performance(1)>, diff --git a/v2v/Makefile.am b/v2v/Makefile.am new file mode 100644 index 0000000..53bc8f2 --- /dev/null +++ b/v2v/Makefile.am @@ -0,0 +1,167 @@ +# libguestfs virt-v2v tool +# Copyright (C) 2009-2014 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + +include $(top_srcdir)/subdir-rules.mk + +EXTRA_DIST = \ + $(SOURCES) \ + virt-v2v.pod + +CLEANFILES = *~ *.cmi *.cmo *.cmx *.cmxa *.o virt-v2v + +# Alphabetical order. +SOURCES = \ + cmdline.ml \ + source_libvirt.ml \ + source_libvirt.mli \ + types.ml \ + types.mli \ + utils.ml \ + v2v.ml \ + xml.ml \ + xml.mli + +if HAVE_OCAML + +# Note this list must be in dependency order. +deps = \ + $(top_builddir)/fish/guestfish-progress.o \ + $(top_builddir)/mllib/tty-c.o \ + $(top_builddir)/mllib/progress-c.o \ + $(top_builddir)/mllib/common_gettext.cmx \ + $(top_builddir)/mllib/common_utils.cmx \ + $(top_builddir)/mllib/tTY.cmx \ + $(top_builddir)/mllib/progress.cmx \ + $(top_builddir)/mllib/config.cmx \ + types.cmx \ + utils.cmx \ + xml-c.o \ + xml.cmx \ + source_libvirt.cmx \ + cmdline.cmx \ + v2v.cmx + +if HAVE_OCAMLOPT +OBJECTS = $(deps) +else +OBJECTS = $(patsubst %.cmx,%.cmo,$(deps)) +endif + +bin_SCRIPTS = virt-v2v + +# -I $(top_builddir)/src/.libs is a hack which forces corresponding -L +# option to be passed to gcc, so we don't try linking against an +# installed copy of libguestfs. +OCAMLPACKAGES = \ + -package str,unix \ + -I $(top_builddir)/src/.libs \ + -I ../gnulib/lib/.libs \ + -I $(top_builddir)/ocaml \ + -I $(top_builddir)/mllib +if HAVE_OCAML_PKG_GETTEXT +OCAMLPACKAGES += -package gettext-stub +endif + +OCAMLCFLAGS = -g -warn-error CDEFLMPSUVYZX $(OCAMLPACKAGES) +OCAMLOPTFLAGS = $(OCAMLCFLAGS) + +if HAVE_OCAMLOPT +virt-v2v: $(OBJECTS) + $(OCAMLFIND) ocamlopt $(OCAMLOPTFLAGS) \ + mlguestfs.cmxa -linkpkg $^ \ + -cclib '-lutils -lncurses $(LIBXML2_LIBS) -lgnu' \ + $(OCAML_GCOV_LDFLAGS) \ + -o $@ +else +virt-v2v: $(OBJECTS) + $(OCAMLFIND) ocamlc $(OCAMLCFLAGS) \ + mlguestfs.cma -linkpkg $^ \ + -cclib '-lutils -lncurses $(LIBXML2_LIBS) -lgnu' \ + -custom \ + $(OCAML_GCOV_LDFLAGS) \ + -o $@ +endif + +.mli.cmi: + $(OCAMLFIND) ocamlc $(OCAMLCFLAGS) -c $< -o $@ +.ml.cmo: + $(OCAMLFIND) ocamlc $(OCAMLCFLAGS) -c $< -o $@ +.ml.cmx: + $(OCAMLFIND) ocamlopt $(OCAMLOPTFLAGS) -c $< -o $@ + +# automake will decide we don't need C support in this file. Really +# we do, so we have to provide it ourselves. + +DEFAULT_INCLUDES = \ + -I. \ + -I$(top_builddir) \ + -I$(shell $(OCAMLC) -where) \ + -I$(top_srcdir)/src \ + -I$(top_srcdir)/fish \ + $(LIBXML2_CFLAGS) + +.c.o: + $(CC) $(CFLAGS) $(PROF_CFLAGS) $(DEFAULT_INCLUDES) -c $< -o $@ + +# Manual pages and HTML files for the website. + +man_MANS = virt-v2v.1 + +noinst_DATA = $(top_builddir)/html/virt-v2v.1.html + +virt-v2v.1 $(top_builddir)/html/virt-v2v.1.html: stamp-virt-v2v.pod + +stamp-virt-v2v.pod: virt-v2v.pod + $(PODWRAPPER) \ + --man virt-v2v.1 \ + --html $(top_builddir)/html/virt-v2v.1.html \ + --license GPLv2+ \ + $< + touch $@ + +CLEANFILES += stamp-virt-v2v.pod + +# Tests. + +TESTS_ENVIRONMENT = $(top_builddir)/run --test + +if ENABLE_APPLIANCE +TESTS = +endif ENABLE_APPLIANCE + +check-valgrind: + $(MAKE) VG="$(top_builddir)/run @VG@" check + +# Dependencies. +depend: .depend + +.depend: $(wildcard $(abs_srcdir)/*.mli) $(wildcard $(abs_srcdir)/*.ml) + rm -f $@ $@-t + $(OCAMLFIND) ocamldep -I ../ocaml -I $(abs_srcdir) -I $(abs_top_builddir)/mllib $^ | \ + $(SED) 's/ *$$//' | \ + $(SED) -e :a -e '/ *\\$$/N; s/ *\\\n */ /; ta' | \ + $(SED) -e 's,$(abs_srcdir)/,$(builddir)/,g' | \ + sort > $@-t + mv $@-t $@ + +-include .depend + +endif + +DISTCLEANFILES = .depend + +.PHONY: depend docs diff --git a/v2v/cmdline.ml b/v2v/cmdline.ml new file mode 100644 index 0000000..ac58576 --- /dev/null +++ b/v2v/cmdline.ml @@ -0,0 +1,141 @@ +(* virt-v2v + * Copyright (C) 2009-2014 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., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + *) + +(* Command line argument parsing. *) + +open Printf + +open Common_gettext.Gettext +open Common_utils + +open Types +open Utils + +let parse_cmdline () = + let display_version () = + printf "virt-v2v %s\n" Config.package_version; + exit 0 + in + + let debug_gc = ref false in + let input_conn = ref "" in + let machine_readable = ref false in + let quiet = ref false in + let verbose = ref false in + let trace = ref false in + + let input_mode = ref `Libvirt in + let set_input_mode = function + | "libvirt" -> input_mode := `Libvirt + | "libvirtxml" -> input_mode := `LibvirtXML + | s -> + error (f_"unknown -i option: %s") s + in + + let root_choice = ref `Ask in + let set_root_choice = function + | "ask" -> root_choice := `Ask + | "single" -> root_choice := `Single + | "first" -> root_choice := `First + | dev when string_prefix dev "/dev/" -> root_choice := `Dev dev + | s -> + error (f_"unknown --root option: %s") s + in + + let ditto = " -\"-" in + let argspec = Arg.align [ + "--debug-gc",Arg.Set debug_gc, " " ^ s_"Debug GC and memory allocations"; + "-i", Arg.String set_input_mode, "libvirtxml|libvirt " ^ s_"Set input mode (default: libvirt)"; + "-ic", Arg.Set_string input_conn, "uri " ^ s_"Libvirt URI"; + "--long-options", Arg.Unit display_long_options, " " ^ s_"List long options"; + "--machine-readable", Arg.Set machine_readable, " " ^ s_"Make output machine readable"; + "-q", Arg.Set quiet, " " ^ s_"Quiet output"; + "--quiet", Arg.Set quiet, ditto; + "--root", Arg.String set_root_choice,"ask|... " ^ s_"How to choose root filesystem"; + "-v", Arg.Set verbose, " " ^ s_"Enable debugging messages"; + "--verbose", Arg.Set verbose, ditto; + "-V", Arg.Unit display_version, " " ^ s_"Display version and exit"; + "--version", Arg.Unit display_version, ditto; + "-x", Arg.Set trace, " " ^ s_"Enable tracing of libguestfs calls"; + ] in + long_options := argspec; + let args = ref [] in + let anon_fun s = args := s :: !args in + let usage_msg = + sprintf (f_"\ +%s: convert a guest to use KVM + + virt-v2v -ic esx://esx.example.com/ -os imported esx_guest + + virt-v2v -ic esx://esx.example.com/ \ + -o rhev -os rhev.nfs:/export_domain --network rhevm esx_guest + + virt-v2v -i libvirtxml guest-domain.xml + +There is a companion front-end called \"virt-p2v\" which comes as an +ISO or CD image that can be booted on physical machines. + +A short summary of the options is given below. For detailed help please +read the man page virt-v2v(1). +") + prog in + Arg.parse argspec anon_fun usage_msg; + + (* Dereference the arguments. *) + let args = List.rev !args in + let debug_gc = !debug_gc in + let input_conn = match !input_conn with "" -> None | s -> Some s in + let input_mode = !input_mode in + let machine_readable = !machine_readable in + let quiet = !quiet in + let root_choice = !root_choice in + let verbose = !verbose in + let trace = !trace in + + (* No arguments and machine-readable mode? Print out some facts + * about what this binary supports. + *) + if args = [] && machine_readable then ( + printf "virt-v2v\n"; + printf "libguestfs-rewrite\n"; + exit 0 + ); + + (* Parsing of the argument(s) depends on the input mode. *) + let input = + match input_mode with + | `Libvirt -> + (* -i libvirt: Expecting a single argument which is the name + * of the libvirt guest. + *) + let guest = + match args with + | [guest] -> guest + | _ -> + error (f_"expecting a libvirt guest name on the command line") in + Libvirt (input_conn, guest) + | `LibvirtXML -> + (* -i libvirtxml: Expecting a filename (XML file). *) + let filename = + match args with + | [filename] -> filename + | _ -> + error (f_"expecting a libvirt XML file name on the command line") in + LibvirtXML filename in + + debug_gc, quiet, input, root_choice, trace, verbose diff --git a/v2v/source_libvirt.ml b/v2v/source_libvirt.ml new file mode 100644 index 0000000..4dc8b59 --- /dev/null +++ b/v2v/source_libvirt.ml @@ -0,0 +1,110 @@ +(* virt-v2v + * Copyright (C) 2009-2014 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., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + *) + +open Printf + +open Common_gettext.Gettext +open Common_utils + +open Types +open Utils + +let create_xml xml = + let doc = Xml.parse_memory xml in + let xpathctx = Xml.xpath_new_context doc in + + let xpath_to_string expr default = + let obj = Xml.xpath_eval_expression xpathctx expr in + if Xml.xpathobj_nr_nodes obj < 1 then default + else ( + let node = Xml.xpathobj_node doc obj 0 in + Xml.node_as_string node + ) in + let xpath_to_int expr default = + let obj = Xml.xpath_eval_expression xpathctx expr in + if Xml.xpathobj_nr_nodes obj < 1 then default + else ( + let node = Xml.xpathobj_node doc obj 0 in + let str = Xml.node_as_string node in + try int_of_string str + with Failure "int_of_string" -> + error (f_"expecting XML expression to return an integer (expression: %s)") + expr + ) in + + let dom_type = xpath_to_string "/domain/@type" "" in + let name = xpath_to_string "/domain/name/text()" "" in + let memory = xpath_to_int "/domain/memory/text()" 0 in + let memory = Int64.of_int memory *^ 1024L in + let vcpu = xpath_to_int "/domain/vcpu/text()" 0 in + let arch = xpath_to_string "/domain/os/type/@arch" "" in + + let features = + let features = ref [] in + let obj = Xml.xpath_eval_expression xpathctx "/domain/features/*" in + let nr_nodes = Xml.xpathobj_nr_nodes obj in + for i = 0 to nr_nodes-1 do + let node = Xml.xpathobj_node doc obj i in + features := Xml.node_name node :: !features + done; + !features in + + (* Non-removable disk devices. *) + let disks = + let disks = ref [] in + let obj = + Xml.xpath_eval_expression xpathctx + "/domain/devices/disk[@device='disk']" in + let nr_nodes = Xml.xpathobj_nr_nodes obj in + if nr_nodes < 1 then + error (f_"this guest has no non-removable disks"); + for i = 0 to nr_nodes-1 do + let node = Xml.xpathobj_node doc obj i in + Xml.xpathctx_set_current_context xpathctx node; + let path = xpath_to_string "source/@file | source/@dev" "" in + if path <> "" then ( + let format = + let format = xpath_to_string "driver/@type" "" in + if format <> "" then Some format else None in + disks := (path, format) :: !disks + ) + done; + List.rev !disks in + + { + s_dom_type = dom_type; + s_name = name; + s_memory = memory; + s_vcpu = vcpu; + s_arch = arch; + s_features = features; + s_disks = disks; + } + +let create_from_xml file = + let xml = read_whole_file file in + create_xml xml + +let create libvirt_uri guest = + let cmd = + match libvirt_uri with + | None -> sprintf "virsh dumpxml %s" (quote guest) + | Some uri -> sprintf "virsh -c %s dumpxml %s" (quote uri) (quote guest) in + let lines = external_command ~prog cmd in + let xml = String.concat "\n" lines in + create_xml xml diff --git a/v2v/source_libvirt.mli b/v2v/source_libvirt.mli new file mode 100644 index 0000000..1e3b1e1 --- /dev/null +++ b/v2v/source_libvirt.mli @@ -0,0 +1,27 @@ +(* virt-v2v + * Copyright (C) 2009-2014 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., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + *) + +(** [-i libvirt] and [-i libvirtxml] sources. *) + +val create : string option -> string -> Types.source +(** [create libvirt_uri guest] reads the source metadata from the + named libvirt guest. *) + +val create_from_xml : string -> Types.source +(** [create_from_xml filename] reads the source metadata from the + libvirt XML file. *) diff --git a/v2v/types.ml b/v2v/types.ml new file mode 100644 index 0000000..447e18a --- /dev/null +++ b/v2v/types.ml @@ -0,0 +1,35 @@ +(* virt-v2v + * Copyright (C) 2009-2014 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., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + *) + +(* Types. See types.mli for documentation. *) + +type input = +| Libvirt of string option * string +| LibvirtXML of string + +type source = { + s_dom_type : string; + s_name : string; + s_memory : int64; + s_vcpu : int; + s_arch : string; + s_features : string list; + s_disks : source_disk list; +} + +and source_disk = string * string option diff --git a/v2v/types.mli b/v2v/types.mli new file mode 100644 index 0000000..7272e9b --- /dev/null +++ b/v2v/types.mli @@ -0,0 +1,38 @@ +(* virt-v2v + * Copyright (C) 2009-2014 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., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + *) + +(** Types. *) + +type input = +| Libvirt of string option * string (* -i libvirt: -ic + guest name *) +| LibvirtXML of string (* -i libvirtxml: XML file name *) +(** The input arguments as specified on the command line. *) + +type source = { + s_dom_type : string; (** Source domain type, eg "kvm" *) + s_name : string; (** Guest name. *) + s_memory : int64; (** Memory size (bytes). *) + s_vcpu : int; (** Number of CPUs. *) + s_arch : string; (** Architecture. *) + s_features : string list; (** Machine features. *) + s_disks : source_disk list; (** Disk images. *) +} +(** The source: metadata, disk images. *) + +and source_disk = string * string option +(** A source file is a qemu URI and a format. *) diff --git a/v2v/utils.ml b/v2v/utils.ml new file mode 100644 index 0000000..d7c41dd --- /dev/null +++ b/v2v/utils.ml @@ -0,0 +1,31 @@ +(* virt-v2v + * Copyright (C) 2009-2014 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., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + *) + +(* Utilities used in virt-v2v only. *) + +open Printf + +open Common_gettext.Gettext +open Common_utils + +open Types + +let prog = Filename.basename Sys.executable_name +let error ?exit_code fs = error ~prog ?exit_code fs + +let quote = Filename.quote diff --git a/v2v/v2v.ml b/v2v/v2v.ml new file mode 100644 index 0000000..4749d98 --- /dev/null +++ b/v2v/v2v.ml @@ -0,0 +1,200 @@ +(* virt-v2v + * Copyright (C) 2009-2014 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., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + *) + +open Unix +open Printf + +open Common_gettext.Gettext + +module G = Guestfs + +open Common_utils +open Types +open Utils + +let () = Random.self_init () + +let rec main () = + (* Handle the command line. *) + let debug_gc, quiet, input, root_choice, trace, verbose = + Cmdline.parse_cmdline () in + + let msg fs = make_message_function ~quiet fs in + + let source = + match input with + | Libvirt (libvirt_uri, guest) -> Source_libvirt.create libvirt_uri guest + | LibvirtXML filename -> Source_libvirt.create_from_xml filename in + + (* Create a qcow2 v3 overlay to protect the source image(s). There + * is a specific reason to use the newer qcow2 variant: Because the + * L2 table can store zero clusters efficiently, and because + * discarded blocks are stored as zero clusters, this should allow us + * to fstrim/blkdiscard and avoid copying significant parts of the + * data over the wire. + *) + msg (f_"Creating an overlay to protect the source from being modified"); + let overlays = + List.map ( + fun (qemu_uri, format) -> + let overlay = Filename.temp_file "v2vovl" ".qcow2" in + let options = + "compat=1.1,lazy_refcounts=on" ^ + (match format with None -> "" + | Some fmt -> ",backing_fmt=" ^ fmt) in + let cmd = + sprintf "qemu-img create -q -f qcow2 -b %s -o %s %s" + (quote qemu_uri) (quote options) overlay in + if Sys.command cmd <> 0 then + error (f_"qemu-img command failed, see earlier errors"); + overlay + ) source.s_disks in + + (* Open the guestfs handle. *) + msg (f_"Opening the source"); + let g = new G.guestfs () in + g#set_trace trace; + g#set_verbose verbose; + List.iter ( + fun overlay -> + g#add_drive_opts overlay + ~format:"qcow2" ~cachemode:"unsafe" ~discard:"besteffort" + ) overlays; + + g#launch (); + + (* Inspection. *) + msg (f_"Inspecting the source"); + let root = inspect_source g root_choice in + + (* Conversion. *) + let () = + let prod = g#inspect_get_product_name root in + let name = + match prod with + | "unknown" -> s_"source" + | prod -> prod in + msg (f_"Converting %s to run on KVM") name in + + (* XXX conversion *) + + (* XXX fstrim here to reduce transfer sizes XXX *) + + g#shutdown (); + g#close (); + +(* + (* Copy the source to the output. *) + iteri ( + fun i overlay -> + msg (f_"Copying disk %d/%d") i (List.length overlays); + + let cmd = + sprintf "qemu-img convert -f qcow2 %s -O %s %s" + overlay output_format XXX in + if Sys.command cmd <> 0 then + error (f_"qemu-img command failed, see earlier errors"); + ) overlays; +*) + + (* XXX Metadata, etc. *) + + msg (f_"Finishing off"); + + if debug_gc then + Gc.compact () + +and inspect_source g root_choice = + let roots = g#inspect_os () in + let roots = Array.to_list roots in + + match roots with + | [] -> + error (f_"no root device found in this operating system image."); + | [root] -> root + | roots -> + match root_choice with + | `Ask -> + (* List out the roots and ask the user to choose. *) + printf "\n***\n"; + printf (f_"dual- or multi-boot operating system detected. Choose the root filesystem\nthat contains the main operating system from the list below:\n"); + printf "\n"; + iteri ( + fun i root -> + let prod = g#inspect_get_product_name root in + match prod with + | "unknown" -> printf " [%d] %s\n" i root + | prod -> printf " [%d] %s (%s)\n" i root prod + ) roots; + printf "\n"; + let i = ref 0 in + let n = List.length roots in + while !i < 1 || !i > n do + printf (f_"Enter number between 1 and %d: ") n; + (try i := int_of_string (read_line ()) + with + | End_of_file -> error (f_"connection closed") + | Failure "int_of_string" -> () + ) + done; + List.nth roots (!i - 1) + + | `Single -> + error (f_"multi-boot operating systems are not supported by virt-v2v. Use the --root option to change how virt-v2v handles this.") + + | `First -> + List.hd roots + + | `Dev dev -> + if List.mem dev roots then dev + else ( + error (f_"root device %s not found. Roots found were: %s") + dev (String.concat " " roots) + ) + +let () = + try main () + with + | Unix.Unix_error (code, fname, "") -> (* from a syscall *) + eprintf (f_"%s: error: %s: %s\n") prog fname (Unix.error_message code); + exit 1 + | Unix.Unix_error (code, fname, param) -> (* from a syscall *) + eprintf (f_"%s: error: %s: %s: %s\n") prog fname (Unix.error_message code) + param; + exit 1 + | Sys_error msg -> (* from a syscall *) + eprintf (f_"%s: error: %s\n") prog msg; + exit 1 + | G.Error msg -> (* from libguestfs *) + eprintf (f_"%s: libguestfs error: %s\n") prog msg; + exit 1 + | Failure msg -> (* from failwith/failwithf *) + eprintf (f_"%s: failure: %s\n") prog msg; + exit 1 + | Invalid_argument msg -> (* probably should never happen *) + eprintf (f_"%s: internal error: invalid argument: %s\n") prog msg; + exit 1 + | Assert_failure (file, line, char) -> (* should never happen *) + eprintf (f_"%s: internal error: assertion failed at %s, line %d, char %d\n") prog file line char; + exit 1 + | Not_found -> (* should never happen *) + eprintf (f_"%s: internal error: Not_found exception was thrown\n") prog; + exit 1 + | exn -> (* something not matched above *) + eprintf (f_"%s: exception: %s\n") prog (Printexc.to_string exn); + exit 1 diff --git a/v2v/virt-v2v.pod b/v2v/virt-v2v.pod new file mode 100644 index 0000000..7580c6b --- /dev/null +++ b/v2v/virt-v2v.pod @@ -0,0 +1,204 @@ +=head1 NAME + +virt-v2v - Convert a guest to use KVM + +=head1 SYNOPSIS + + virt-v2v -ic esx://esx.example.com/ -os imported esx_guest + + virt-v2v -ic esx://esx.example.com/ \ + -o rhev -os rhev.nfs:/export_domain --network rhevm esx_guest + + virt-v2v -i libvirtxml guest-domain.xml + +=head1 DESCRIPTION + +Virt-v2v converts guests from a foreign hypervisor to run on KVM, +managed by libvirt or Red Hat Enterprise Virtualisation (RHEV) version +2.2 or later. It can currently convert Red Hat Enterprise Linux and +Windows guests running on Xen and VMware ESX. + +There is also a companion front-end called "virt-p2v" which comes as an +ISO or CD image that can be booted on physical machines. + +=head1 OPTIONS + +=over 4 + +=item B<--help> + +Display help. + +=item B<--debug-gc> + +Debug garbage collection and memory allocation. This is only useful +when debugging memory problems in virt-v2v or the OCaml libguestfs +bindings. + +=item B<--machine-readable> + +This option is used to make the output more machine friendly +when being parsed by other programs. See +L</MACHINE READABLE OUTPUT> below. + +=item B<-q> + +=item B<--quiet> + +This disables progress bars and other unnecessary output. + +=item B<--root ask> + +=item B<--root single> + +=item B<--root first> + +=item B<--root> /dev/sdX + +=item B<--root> /dev/VG/LV + +Choose the root filesystem to be converted. + +In the case where the virtual machine is dual-boot or multi-boot, or +where the VM has other filesystems that look like operating systems, +this option can be used to select the root filesystem (a.k.a. C<C:> +drive or C</>) of the operating system that is to be converted. The +Windows Recovery Console, certain attached DVD drives, and bugs in +libguestfs inspection heuristics, can make a guest look like a +multi-boot operating system. + +The default in virt-v2v E<le> 0.7.1 was S<I<--root single>>, which +causes virt-v2v to die if a multi-boot operating system is found. + +Since virt-v2v E<ge> 0.7.2 the default is now S<I<--root ask>>: If the +VM is found to be multi-boot, then virt-v2v will stop and list the +possible root filesystems and ask the user which to use. This +requires that virt-v2v is run interactively. + +S<I<--root first>> means to choose the first root device in the case +of a multi-boot operating system. Since this is a heuristic, it may +sometimes choose the wrong one. + +You can also name a specific root device, eg. S<I<--root /dev/sda2>> +would mean to use the second partition on the first hard drive. If +the named root device does not exist or was not detected as a root +device, then virt-v2v will fail. + +Note that there is a bug in grub which prevents it from successfully +booting a multiboot system if VirtIO is enabled. Grub is only able to +boot an operating system from the first VirtIO disk. Specifically, +C</boot> must be on the first VirtIO disk, and it cannot chainload an +OS which is not in the first VirtIO disk. + +=item B<-v> + +=item B<--verbose> + +Enable verbose messages for debugging. + +=item B<-V> + +=item B<--version> + +Display version number and exit. + +=item B<-x> + +Enable tracing of libguestfs API calls. + +=back + +=head1 MACHINE READABLE OUTPUT + +The I<--machine-readable> option can be used to make the output more +machine friendly, which is useful when calling virt-v2v from +other programs, GUIs etc. + +There are two ways to use this option. + +Firstly use the option on its own to query the capabilities of the +virt-v2v binary. Typical output looks like this: + + $ virt-v2v --machine-readable + virt-v2v + libguestfs-rewrite + +A list of features is printed, one per line, and the program exits +with status 0. + +Secondly use the option in conjunction with other options to make the +regular program output more machine friendly. + +At the moment this means: + +=over 4 + +=item 1. + +Progress bar messages can be parsed from stdout by looking for this +regular expression: + + ^[0-9]+/[0-9]+$ + +=item 2. + +The calling program should treat messages sent to stdout (except for +progress bar messages) as status messages. They can be logged and/or +displayed to the user. + +=item 3. + +The calling program should treat messages sent to stderr as error +messages. In addition, virt-v2v exits with a non-zero status +code if there was a fatal error. + +=back + +Virt-v2v E<le> 0.9.1 did not support the I<--machine-readable> +option at all. The option was added when virt-v2v was rewritten in 2014. + +=head1 ENVIRONMENT VARIABLES + +=over 4 + +=item TMPDIR + +Location of the temporary directory used for the potentially large +temporary overlay file. + +You should ensure there is enough free space in the worst case for a +full copy of the source disk (I<virtual> size), or else set C<$TMPDIR> +to point to another directory that has enough space. + +This defaults to C</tmp>. + +Note that if C<$TMPDIR> is a tmpfs (eg. if C</tmp> is on tmpfs, or if +you use C<TMPDIR=/dev/shm>), tmpfs defaults to a maximum size of +I<half> of physical RAM. If virt-v2v exceeds this, it will hang. +The solution is either to use a real disk, or to increase the maximum +size of the tmpfs mountpoint, eg: + + mount -o remount,size=10G /tmp + +=back + +For other environment variables, see L<guestfs(3)/ENVIRONMENT VARIABLES>. + +=head1 SEE ALSO + +L<virt-df(1)>, +L<virt-filesystems(1)>, +L<guestfs(3)>, +L<guestfish(1)>, +L<qemu-img(1)>, +L<http://libguestfs.org/>. + +=head1 AUTHORS + +Richard W.M. Jones L<http://people.redhat.com/~rjones/> + +Matthew Booth + +=head1 COPYRIGHT + +Copyright (C) 2009-2014 Red Hat Inc. diff --git a/v2v/xml-c.c b/v2v/xml-c.c new file mode 100644 index 0000000..9b79c6b --- /dev/null +++ b/v2v/xml-c.c @@ -0,0 +1,240 @@ +/* virt-v2v + * Copyright (C) 2009-2014 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., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +/* Mini interface to libxml2 for parsing libvirt XML. */ + +#include <config.h> + +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> + +#include <caml/alloc.h> +#include <caml/custom.h> +#include <caml/fail.h> +#include <caml/memory.h> +#include <caml/mlvalues.h> + +#include <libxml/xpath.h> + +#include "guestfs.h" +#include "guestfs-internal-frontend.h" + +/* xmlDocPtr type */ +#define Doc_val(v) (*((xmlDocPtr *)Data_custom_val(v))) + +static void +doc_finalize (value docv) +{ + xmlDocPtr doc = Doc_val (docv); + + if (doc) + xmlFreeDoc (doc); +} + +static struct custom_operations doc_custom_operations = { + (char *) "doc_custom_operations", + doc_finalize, + custom_compare_default, + custom_hash_default, + custom_serialize_default, + custom_deserialize_default +}; + +/* xmlXPathContextPtr type */ +#define Xpathctx_val(v) (*((xmlXPathContextPtr *)Data_custom_val(v))) + +static void +xpathctx_finalize (value xpathctxv) +{ + xmlXPathContextPtr xpathctx = Xpathctx_val (xpathctxv); + + if (xpathctx) + xmlXPathFreeContext (xpathctx); +} + +static struct custom_operations xpathctx_custom_operations = { + (char *) "xpathctx_custom_operations", + xpathctx_finalize, + custom_compare_default, + custom_hash_default, + custom_serialize_default, + custom_deserialize_default +}; + +/* xmlXPathObjectPtr type */ +#define Xpathobj_val(v) (*((xmlXPathObjectPtr *)Data_custom_val(v))) + +static void +xpathobj_finalize (value xpathobjv) +{ + xmlXPathObjectPtr xpathobj = Xpathobj_val (xpathobjv); + + if (xpathobj) + xmlXPathFreeObject (xpathobj); +} + +static struct custom_operations xpathobj_custom_operations = { + (char *) "xpathobj_custom_operations", + xpathobj_finalize, + custom_compare_default, + custom_hash_default, + custom_serialize_default, + custom_deserialize_default +}; + +value +v2v_xml_parse_memory (value xmlv) +{ + CAMLparam1 (xmlv); + CAMLlocal1 (docv); + xmlDocPtr doc; + + doc = xmlParseMemory (String_val (xmlv), caml_string_length (xmlv)); + if (doc == NULL) + caml_invalid_argument ("parse_memory: unable to parse XML from libvirt"); + + docv = caml_alloc_custom (&doc_custom_operations, sizeof (xmlDocPtr), 0, 1); + Doc_val (docv) = doc; + + CAMLreturn (docv); +} + +value +v2v_xml_xpath_new_context (value docv) +{ + CAMLparam1 (docv); + CAMLlocal1 (xpathctxv); + xmlDocPtr doc; + xmlXPathContextPtr xpathctx; + + doc = Doc_val (docv); + xpathctx = xmlXPathNewContext (doc); + if (xpathctx == NULL) + caml_invalid_argument ("xpath_new_context: unable to create xmlXPathNewContext"); + + xpathctxv = caml_alloc_custom (&xpathctx_custom_operations, + sizeof (xmlXPathContextPtr), 0, 1); + Xpathctx_val (xpathctxv) = xpathctx; + + CAMLreturn (xpathctxv); +} + +value +v2v_xml_xpath_eval_expression (value xpathctxv, value exprv) +{ + CAMLparam2 (xpathctxv, exprv); + CAMLlocal1 (xpathobjv); + xmlXPathContextPtr xpathctx; + xmlXPathObjectPtr xpathobj; + + xpathctx = Xpathctx_val (xpathctxv); + xpathobj = xmlXPathEvalExpression (BAD_CAST String_val (exprv), xpathctx); + if (xpathobj == NULL) + caml_invalid_argument ("xpath_eval_expression: unable to evaluate XPath expression"); + + xpathobjv = caml_alloc_custom (&xpathobj_custom_operations, + sizeof (xmlXPathObjectPtr), 0, 1); + Xpathobj_val (xpathobjv) = xpathobj; + + CAMLreturn (xpathobjv); +} + +value +v2v_xml_xpathobj_nr_nodes (value xpathobjv) +{ + CAMLparam1 (xpathobjv); + xmlXPathObjectPtr xpathobj = Xpathobj_val (xpathobjv); + + CAMLreturn (Val_int (xpathobj->nodesetval->nodeNr)); +} + +value +v2v_xml_xpathobj_get_node_ptr (value xpathobjv, value iv) +{ + CAMLparam2 (xpathobjv, iv); + xmlXPathObjectPtr xpathobj = Xpathobj_val (xpathobjv); + int i = Int_val (iv); + + /* Because xmlNodePtrs are owned by the document, we don't want to + * wrap this up with a finalizer, so just pass the pointer straight + * back to OCaml as a value. OCaml will ignore it because it's + * outside the heap, and just pass it back to us when needed. This + * relies on the xmlDocPtr not being freed, but we pair the node + * pointer with the doc in the OCaml layer so the GC will not free + * one without freeing the other. + */ + CAMLreturn ((value) xpathobj->nodesetval->nodeTab[i]); +} + +value +v2v_xml_xpathctx_set_node_ptr (value xpathctxv, value nodev) +{ + CAMLparam2 (xpathctxv, nodev); + xmlXPathContextPtr xpathctx = Xpathctx_val (xpathctxv); + xmlNodePtr node = (xmlNodePtr) nodev; + + xpathctx->node = node; + + CAMLreturn (Val_unit); +} + +value +v2v_xml_node_ptr_name (value nodev) +{ + CAMLparam1 (nodev); + xmlNodePtr node = (xmlNodePtr) nodev; + + switch (node->type) { + case XML_ATTRIBUTE_NODE: + case XML_ELEMENT_NODE: + CAMLreturn (caml_copy_string ((char *) node->name)); + + default: + caml_invalid_argument ("node_name: don't know how to get the name of this node"); + } +} + +value +v2v_xml_node_ptr_as_string (value docv, value nodev) +{ + CAMLparam2 (docv, nodev); + xmlDocPtr doc = Doc_val (docv); + xmlNodePtr node = (xmlNodePtr) nodev; + CLEANUP_FREE char *str = NULL; + + switch (node->type) { + case XML_TEXT_NODE: + case XML_COMMENT_NODE: + case XML_CDATA_SECTION_NODE: + case XML_PI_NODE: + CAMLreturn (caml_copy_string ((char *) node->content)); + + case XML_ATTRIBUTE_NODE: + case XML_ELEMENT_NODE: + str = (char *) xmlNodeListGetString (doc, node->children, 1); + + if (str == NULL) + caml_invalid_argument ("node_as_string: xmlNodeListGetString cannot convert node to string"); + + CAMLreturn (caml_copy_string (str)); + + default: + caml_invalid_argument ("node_as_string: don't know how to convert this node to a string"); + } +} diff --git a/v2v/xml.ml b/v2v/xml.ml new file mode 100644 index 0000000..5cd75c1 --- /dev/null +++ b/v2v/xml.ml @@ -0,0 +1,50 @@ +(* virt-v2v + * Copyright (C) 2009-2014 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., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + *) + +(* Mini interface to libxml2 for parsing libvirt XML. *) + +type doc +type node_ptr +type xpathctx +type xpathobj + +(* Since node is owned by doc, we have to make that explicit to the + * garbage collector. + *) +type node = doc * node_ptr + +external parse_memory : string -> doc = "v2v_xml_parse_memory" +external xpath_new_context : doc -> xpathctx = "v2v_xml_xpath_new_context" +external xpath_eval_expression : xpathctx -> string -> xpathobj = "v2v_xml_xpath_eval_expression" + +external xpathobj_nr_nodes : xpathobj -> int = "v2v_xml_xpathobj_nr_nodes" +external xpathobj_get_node_ptr : xpathobj -> int -> node_ptr = "v2v_xml_xpathobj_get_node_ptr" +let xpathobj_node doc xpathobj i = + let n = xpathobj_get_node_ptr xpathobj i in + (doc, n) + +external xpathctx_set_node_ptr : xpathctx -> node_ptr -> unit = "v2v_xml_xpathctx_set_node_ptr" +let xpathctx_set_current_context xpathctx (_, node) = + xpathctx_set_node_ptr xpathctx node + +external node_ptr_name : node_ptr -> string = "v2v_xml_node_ptr_name" +let node_name (_, node) = node_ptr_name node + +external node_ptr_as_string : doc -> node_ptr -> string = "v2v_xml_node_ptr_as_string" +let node_as_string (doc, node) = + node_ptr_as_string doc node diff --git a/v2v/xml.mli b/v2v/xml.mli new file mode 100644 index 0000000..c4363ad --- /dev/null +++ b/v2v/xml.mli @@ -0,0 +1,57 @@ +(* virt-v2v + * Copyright (C) 2009-2014 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., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + *) + +(** Mini interface to libxml2 for parsing libvirt XML. *) + +type doc (** xmlDocPtr *) +type node (** xmlNodePtr *) +type xpathctx (** xmlXPathContextPtr *) +type xpathobj (** xmlXPathObjectPtr *) + +val parse_memory : string -> doc +(** xmlParseMemory *) +val xpath_new_context : doc -> xpathctx +(** xmlXPathNewContext *) +val xpath_eval_expression : xpathctx -> string -> xpathobj +(** xmlXPathEvalExpression *) + +val xpathobj_nr_nodes : xpathobj -> int +(** Get the number of nodes in the node set of the xmlXPathObjectPtr. *) +val xpathobj_node : doc -> xpathobj -> int -> node +(** Get the number of nodes in the node set of the xmlXPathObjectPtr. *) + +val xpathctx_set_current_context : xpathctx -> node -> unit +(** Set the current context of an xmlXPathContextPtr to the node. + Basically the same as the following C code: + + {v + xpathctx->node = node + v} + + It means the next expression you evaluate within this context will + start at this node, when evaluating relative paths + (eg. [./@attr]). +*) + +val node_name : node -> string +(** Get the name of the node. Note that only things like elements and + attributes have names. Other types of nodes will return an + error. *) + +val node_as_string : node -> string +(** Converter to turn a node into a string *) -- 1.8.5.3