pylorax.ltmpl — Lorax 28.14.33 documentation

# Source code for pylorax.ltmpl

    #
    # ltmpl.py
    #
    # Copyright (C) 2009-2015  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, see <http://www.gnu.org/licenses/>.
    #
    # Red Hat Author(s):  Martin Gracik <mgracik@redhat.com>
    #                     Will Woods <wwoods@redhat.com>
    #

    import logging
    logger = logging.getLogger("pylorax.ltmpl")

    import os, re, glob, shlex, fnmatch
    from os.path import basename, isdir
    from subprocess import CalledProcessError
    import shutil

    from pylorax.sysutils import joinpaths, cpfile, mvfile, replace, remove
    from pylorax.dnfhelper import LoraxDownloadCallback, LoraxRpmCallback
    from pylorax.base import DataHolder
    from pylorax.executils import runcmd, runcmd_output
    from pylorax.imgutils import mkcpio

    from mako.lookup import TemplateLookup
    from mako.exceptions import text_error_template
    import sys, traceback
    import struct
    import dnf
    import collections

    class LoraxTemplate(object):
        def __init__(self, directories=None):
            directories = directories or ["/usr/share/lorax"]
            # we have to add ["/"] to the template lookup directories or the
            # file includes won't work properly for absolute paths
            self.directories = ["/"] + directories

        def parse(self, template_file, variables):
            lookup = TemplateLookup(directories=self.directories)
            template = lookup.get_template(template_file)

            try:
                textbuf = template.render(**variables)
            except:
                logger.error("Problem rendering %s (%s):", template_file, variables)
                logger.error(text_error_template().render())
                raise

            # split, strip and remove empty lines
            lines = textbuf.splitlines()
            lines = [line.strip() for line in lines]
            lines = [line for line in lines if line]

            # remove comments
            lines = [line for line in lines if not line.startswith("#")]

            # split with shlex and perform brace expansion. This can fail, so we unroll the loop
            # for better error reporting.
            expanded_lines = []
            try:
                for line in lines:
                    expanded_lines.append(split_and_expand(line))
            except Exception as e:
                logger.error('shlex error processing "%s": %s', line, str(e))
                raise
            return expanded_lines

    def split_and_expand(line):
        return [exp for word in shlex.split(line) for exp in brace_expand(word)]

    def brace_expand(s):
        if not ('{' in s and ',' in s and '}' in s):
            yield s
        else:
            right = s.find('}')
            left = s[:right].rfind('{')
            (prefix, choices, suffix) = (s[:left], s[left+1:right], s[right+1:])
            for choice in choices.split(','):
                for alt in brace_expand(prefix+choice+suffix):
                    yield alt

    def rglob(pathname, root="/", fatal=False):
        seen = set()
        rootlen = len(root)+1
        for f in glob.iglob(joinpaths(root, pathname)):
            if f not in seen:
                seen.add(f)
                yield f[rootlen:] # remove the root to produce relative path
        if fatal and not seen:
            raise IOError("nothing matching %s in %s" % (pathname, root))

    def rexists(pathname, root=""):
        # Generator is always True, even with no values;
        # bool(rglob(...)) won't work here.
        for _path in rglob(pathname, root):
            return True
        return False

    class TemplateRunner(object):
        '''
        This class parses and executes Lorax templates. Sample usage:

          # install a bunch of packages
          runner = LoraxTemplateRunner(inroot=rundir, outroot=rundir, dbo=dnf_obj)
          runner.run("install-packages.ltmpl")
        NOTES:

        * Parsing procedure is roughly:
          1. Mako template expansion (on the whole file)
          2. For each line of the result,
            a. Whitespace splitting (using shlex.split())
            b. Brace expansion (using brace_expand())
            c. If the first token is the name of a function, call that function
               with the rest of the line as arguments

        * Parsing and execution are *separate* passes - so you can't use the result
          of a command in an %if statement (or any other control statements)!
        '''
        def __init__(self, fatalerrors=True, templatedir=None, defaults=None, builtins=None):
            self.fatalerrors = fatalerrors
            self.templatedir = templatedir or "/usr/share/lorax"
            self.templatefile = None
            self.builtins = builtins or {}
            self.defaults = defaults or {}

        def run(self, templatefile, **variables):
            for k,v in list(self.defaults.items()) + list(self.builtins.items()):
                variables.setdefault(k,v)
            logger.debug("executing %s with variables=%s", templatefile, variables)
            self.templatefile = templatefile
            t = LoraxTemplate(directories=[self.templatedir])
            commands = t.parse(templatefile, variables)
            self._run(commands)

        def _run(self, parsed_template):
            logger.info("running %s", self.templatefile)
            for (num, line) in enumerate(parsed_template,1):
                logger.debug("template line %i: %s", num, " ".join(line))
                skiperror = False
                (cmd, args) = (line[0], line[1:])
                # Following Makefile convention, if the command is prefixed with
                # a dash ('-'), we'll ignore any errors on that line.
                if cmd.startswith('-'):
                    cmd = cmd[1:]
                    skiperror = True
                try:
                    # grab the method named in cmd and pass it the given arguments
                    f = getattr(self, cmd, None)
                    if cmd[0] == '_' or cmd == 'run' or not isinstance(f, collections.Callable):
                        raise ValueError("unknown command %s" % cmd)
                    f(*args)
                except Exception: # pylint: disable=broad-except
                    if skiperror:
                        logger.debug("ignoring error")
                        continue
                    logger.error("template command error in %s:", self.templatefile)
                    logger.error("  %s", " ".join(line))
                    # format the exception traceback
                    exclines = traceback.format_exception(*sys.exc_info())
                    # skip the bit about "ltmpl.py, in _run()" - we know that
                    exclines.pop(1)
                    # log the "ErrorType: this is what happened" line
                    logger.error("  %s", exclines[-1].strip())
                    # and log the entire traceback to the debug log
                    for _line in ''.join(exclines).splitlines():
                        logger.debug("  %s", _line)
                    if self.fatalerrors:
                        raise

    # TODO: operate inside an actual chroot for safety? Not that RPM bothers..
    class LoraxTemplateRunner(TemplateRunner):
        '''
        This class parses and executes Lorax templates. Sample usage:

          # install a bunch of packages
          runner = LoraxTemplateRunner(inroot=rundir, outroot=rundir, dbo=dnf_obj)
          runner.run("install-packages.ltmpl")

          # modify a runtime dir
          runner = LoraxTemplateRunner(inroot=rundir, outroot=newrun)
          runner.run("runtime-transmogrify.ltmpl")

        NOTES:

        * Commands that run external programs (e.g. systemctl) currently use
          the *host*'s copy of that program, which may cause problems if there's a
          big enough difference between the host and the image you're modifying.

        * The commands are not executed under a real chroot, so absolute symlinks
          will point *outside* the inroot/outroot. Be careful with symlinks!

        ADDING NEW COMMANDS:

        * Each template command is just a method of the LoraxTemplateRunner
          object - so adding a new command is as easy as adding a new function.

        * Each function gets arguments that correspond to the rest of the tokens
          on that line (after word splitting and brace expansion)

        * Commands should raise exceptions for errors - don't use sys.exit()
        '''
        def __init__(self, inroot, outroot, dbo=None, fatalerrors=True,
                                            templatedir=None, defaults=None):
            self.inroot = inroot
            self.outroot = outroot
            self.dbo = dbo
            builtins = DataHolder(exists=lambda p: rexists(p, root=inroot),
                                  glob=lambda g: list(rglob(g, root=inroot)))
            self.results = DataHolder(treeinfo=dict()) # just treeinfo for now

            super(LoraxTemplateRunner, self).__init__(fatalerrors, templatedir, defaults, builtins)
            # TODO: set up custom logger with a filter to add line info

        def _out(self, path):
            return joinpaths(self.outroot, path)
        def _in(self, path):
            return joinpaths(self.inroot, path)

        def _filelist(self, *pkgs):
            """ Return the list of files in the packages """
            pkglist = []
            for pkg_glob in pkgs:
                pkglist += list(self.dbo.sack.query().installed().filter(name__glob=pkg_glob))

            # dnf/hawkey doesn't make any distinction between file, dir or ghost like yum did
            # so only return the files.
            return set(f for pkg in pkglist for f in pkg.files if not os.path.isdir(self._out(f)))

        def _getsize(self, *files):
            return sum(os.path.getsize(self._out(f)) for f in files if os.path.isfile(self._out(f)))

        def _write_debuginfo_log(self):
            """
            Write a list of debuginfo packages to /root/debug-pkgs.log

            If lorax is called with a debug repo find the corresponding debuginfo package
            names and write them to /root/debubg-pkgs.log on the boot.iso
            """
            for repo in self.dbo.repos:
                repo = self.dbo.repos[repo]
                if any(True for url in repo.baseurl if "debug" in url):
                    break
                if repo.metalink and "debug" in repo.metalink:
                    break
                if repo.mirrorlist and "debug" in repo.mirrorlist:
                    break
            else:
                # No debug repos
                return

            available = self.dbo.sack.query().available()
            debug_pkgs = []
            for p in list(self.dbo.transaction.install_set):
                if available.filter(name=p.name+"-debuginfo"):
                    debug_pkgs += ["{0.name}-debuginfo-{0.epoch}:{0.version}-{0.release}".format(p)]

            os.makedirs(self._out("root/"), exist_ok=True)
            with open(self._out("root/debug-pkgs.log"), "w") as f:
                for pkg in debug_pkgs:
                    f.write("%s\n" % pkg)

        def install(self, srcglob, dest):
            '''
            install SRC DEST
              Copy the given file (or files, if a glob is used) from the input
              tree to the given destination in the output tree.
              The path to DEST must exist in the output tree.
              If DEST is a directory, SRC will be copied into that directory.
              If DEST doesn't exist, SRC will be copied to a file with that name,
              assuming the rest of the path exists.
              This is pretty much like how the 'cp' command works.

              Examples:
                install usr/share/myconfig/grub.conf /boot
                install /usr/share/myconfig/grub.conf.in /boot/grub.conf
            '''
            for src in rglob(self._in(srcglob), fatal=True):
                try:
                    cpfile(src, self._out(dest))
                except shutil.Error as e:
                    logger.error(e)

        def installimg(self, *args):
            '''
            installimg [--xz|--gzip|--bzip2|--lzma] [-ARG|--ARG=OPTION] SRCDIR DESTFILE
              Create a compressed cpio archive of the contents of SRCDIR and place
              it in DESTFILE.

              If SRCDIR doesn't exist or is empty nothing is created.

              Examples:
                installimg ${LORAXDIR}/product/ images/product.img
                installimg ${LORAXDIR}/updates/ images/updates.img
                installimg --xz -6 ${LORAXDIR}/updates/ images/updates.img
                installimg --xz -9 --memlimit-compress=3700MiB ${LORAXDIR}/updates/ images/updates.img

              Optionally use a different compression type and override the default args
              passed to it. The default is xz -9
            '''
            COMPRESSORS = ("--xz", "--gzip", "--bzip2", "--lzma")
            if len(args) < 2:
                raise ValueError("Not enough args for installimg.")

            srcdir = args[-2]
            destfile = args[-1]
            if not os.path.isdir(self._in(srcdir)) or not os.listdir(self._in(srcdir)):
                return

            compression = "xz"
            compressargs = []
            if args[0] in COMPRESSORS:
                compression = args[0][2:]

            for arg in args[1:-2]:
                if arg.startswith('-'):
                    compressargs.append(arg)
                else:
                    raise ValueError("Argument is missing -")

            logger.info("Creating image file %s from contents of %s", self._out(destfile), self._in(srcdir))
            logger.debug("Using %s %s compression", compression, compressargs or "")
            mkcpio(self._in(srcdir), self._out(destfile), compression=compression, compressargs=compressargs)

        def mkdir(self, *dirs):
            '''
            mkdir DIR [DIR ...]
              Create the named DIR(s). Will create leading directories as needed.

              Example:
                mkdir /images
            '''
            for d in dirs:
                d = self._out(d)
                if not isdir(d):
                    os.makedirs(d)

        def replace(self, pat, repl, *fileglobs):
            '''
            replace PATTERN REPLACEMENT FILEGLOB [FILEGLOB ...]
              Find-and-replace the given PATTERN (Python-style regex) with the given
              REPLACEMENT string for each of the files listed.

              Example:
                replace @VERSION@ ${product.version} /boot/grub.conf /boot/isolinux.cfg
            '''
            match = False
            for g in fileglobs:
                for f in rglob(self._out(g)):
                    match = True
                    replace(f, pat, repl)
            if not match:
                raise IOError("no files matched %s" % " ".join(fileglobs))

        def append(self, filename, data):
            '''
            append FILE STRING
              Append STRING (followed by a newline character) to FILE.
              Python character escape sequences ('\\n', '\\t', etc.) will be
              converted to the appropriate characters.

              Examples:

                append /etc/depmod.d/dd.conf "search updates built-in"
                append /etc/resolv.conf ""
            '''
            with open(self._out(filename), "a") as fobj:
                fobj.write(bytes(data, "utf8").decode('unicode_escape')+"\n")

        def treeinfo(self, section, key, *valuetoks):
            '''
            treeinfo SECTION KEY ARG [ARG ...]
              Add an item to the treeinfo data store.
              The given SECTION will have a new item added where
              KEY = ARG ARG ...

              Example:
                treeinfo images-${kernel.arch} boot.iso images/boot.iso
            '''
            if section not in self.results.treeinfo:
                self.results.treeinfo[section] = dict()
            self.results.treeinfo[section][key] = " ".join(valuetoks)

        def installkernel(self, section, src, dest):
            '''
            installkernel SECTION SRC DEST
              Install the kernel from SRC in the input tree to DEST in the output
              tree, and then add an item to the treeinfo data store, in the named
              SECTION, where "kernel" = DEST.

              Equivalent to:
                install SRC DEST
                treeinfo SECTION kernel DEST
            '''
            self.install(src, dest)
            self.treeinfo(section, "kernel", dest)

        def installinitrd(self, section, src, dest):
            '''
            installinitrd SECTION SRC DEST
              Same as installkernel, but for "initrd".
            '''
            self.install(src, dest)
            self.chmod(dest, '644')
            self.treeinfo(section, "initrd", dest)

        def installupgradeinitrd(self, section, src, dest):
            '''
            installupgradeinitrd SECTION SRC DEST
              Same as installkernel, but for "upgrade".
            '''
            self.install(src, dest)
            self.chmod(dest, '644')
            self.treeinfo(section, "upgrade", dest)

        def hardlink(self, src, dest):
            '''
            hardlink SRC DEST
              Create a hardlink at DEST which is linked to SRC.
            '''
            if isdir(self._out(dest)):
                dest = joinpaths(dest, basename(src))
            os.link(self._out(src), self._out(dest))

        def symlink(self, target, dest):
            '''
            symlink SRC DEST
              Create a symlink at DEST which points to SRC.
            '''
            if rexists(self._out(dest)):
                self.remove(dest)
            os.symlink(target, self._out(dest))

        def copy(self, src, dest):
            '''
            copy SRC DEST
              Copy SRC to DEST.
              If DEST is a directory, SRC will be copied inside it.
              If DEST doesn't exist, SRC will be copied to a file with
              that name, if the path leading to it exists.
            '''
            try:
                cpfile(self._out(src), self._out(dest))
            except shutil.Error as e:
                logger.error(e)

        def move(self, src, dest):
            '''
            move SRC DEST
              Move SRC to DEST.
            '''
            mvfile(self._out(src), self._out(dest))

        def remove(self, *fileglobs):
            '''
            remove FILEGLOB [FILEGLOB ...]
              Remove all the named files or directories.
              Will *not* raise exceptions if the file(s) are not found.
            '''
            for g in fileglobs:
                for f in rglob(self._out(g)):
                    remove(f)
                    logger.debug("removed %s", f)

        def chmod(self, fileglob, mode):
            '''
            chmod FILEGLOB OCTALMODE
              Change the mode of all the files matching FILEGLOB to OCTALMODE.
            '''
            for f in rglob(self._out(fileglob), fatal=True):
                os.chmod(f, int(mode,8))

        def log(self, msg):
            '''
            log MESSAGE
              Emit the given log message. Be sure to put it in quotes!

              Example:
                log "Reticulating splines, please wait..."
            '''
            logger.info(msg)

        # TODO: add ssh-keygen, mkisofs(?), find, and other useful commands
        def runcmd(self, *cmdlist):
            '''
            runcmd CMD [ARG ...]
              Run the given command with the given arguments.

              NOTE: All paths given MUST be COMPLETE, ABSOLUTE PATHS to the file
              or files mentioned. ${root}/${inroot}/${outroot} are good for
              constructing these paths.

              FURTHER NOTE: Please use this command only as a last resort!
              Whenever possible, you should use the existing template commands.
              If the existing commands don't do what you need, fix them!

              Examples:
                (this should be replaced with a "find" function)
                runcmd find ${root} -name "*.pyo" -type f -delete
                %for f in find(root, name="*.pyo"):
                    remove ${f}
                %endfor
            '''
            cmd = cmdlist
            logger.debug('running command: %s', cmd)
            if cmd[0].startswith("--chdir="):
                logger.error("--chdir is no longer supported for runcmd.")
                raise ValueError("--chdir is no longer supported for runcmd.")

            try:
                stdout = runcmd_output(cmd)
                if stdout:
                    logger.debug('command output:\n%s', stdout)
                logger.debug("command finished successfully")
            except CalledProcessError as e:
                if e.output:
                    logger.error('command output:\n%s', e.output)
                logger.error('command returned failure (%d)', e.returncode)
                raise

        def installpkg(self, *pkgs):
            '''
            installpkg [--required|--optional] [--except PKGGLOB [--except PKGGLOB ...]] PKGGLOB [PKGGLOB ...]
              Request installation of all packages matching the given globs.
              Note that this is just a *request* - nothing is *actually* installed
              until the 'run_pkg_transaction' command is given.

              --required is now the default. If the PKGGLOB can be missing pass --optional
            '''
            if pkgs[0] == '--optional':
                pkgs = pkgs[1:]
                required = False
            elif pkgs[0] == '--required':
                pkgs = pkgs[1:]
                required = True
            else:
                required = True

            excludes = []
            while '--except' in pkgs:
                idx = pkgs.index('--except')
                if len(pkgs) == idx+1:
                    raise ValueError("installpkg needs an argument after --except")

                excludes.append(pkgs[idx+1])
                pkgs = pkgs[:idx] + pkgs[idx+2:]

            errors = False
            for p in pkgs:
                try:
                    # Start by using Subject to generate a package query, which will
                    # give us a query object similar to what dbo.install would select,
                    # minus the handling for multilib. This query may contain
                    # multiple arches. Pull the package names out of that, filter any
                    # that match the excludes patterns, and pass those names back to
                    # dbo.install to do the actual, arch and version and multilib
                    # aware, package selction.

                    # dnf queries don't have a concept of negative globs which is why
                    # the filtering is done the hard way.

                    pkgnames = [pkg for pkg in dnf.subject.Subject(p).get_best_query(self.dbo.sack).filter(latest=True)]
                    if not pkgnames:
                        raise dnf.exceptions.PackageNotFoundError("no package matched", p)

                    # Apply excludes to the name only
                    for exclude in excludes:
                        pkgnames = [pkg for pkg in pkgnames if not fnmatch.fnmatch(pkg.name, exclude)]

                    # Convert to a sorted NVR list for installation
                    pkgnvrs = sorted(["{}-{}-{}".format(pkg.name, pkg.version, pkg.release) for pkg in pkgnames])

                    # If the request is a glob, expand it in the log
                    if any(g for g in ['*','?','.'] if g in p):
                        logger.info("installpkg: %s expands to %s", p, ",".join(pkgnvrs))

                    for pkgnvr in pkgnvrs:
                        try:
                            self.dbo.install(pkgnvr)
                        except Exception as e: # pylint: disable=broad-except
                            if required:
                                raise
                            # Not required, log it and continue processing pkgs
                            logger.error("installpkg %s failed: %s", pkgnvr, str(e))
                except Exception as e: # pylint: disable=broad-except
                    logger.error("installpkg %s failed: %s", p, str(e))
                    errors = True

            if errors and required:
                raise Exception("Required installpkg failed.")

        def removepkg(self, *pkgs):
            '''
            removepkg PKGGLOB [PKGGLOB...]
              Delete the named package(s).

              IMPLEMENTATION NOTES:
                RPM scriptlets (%preun/%postun) are *not* run.
                Files are deleted, but directories are left behind.
            '''
            for p in pkgs:
                filepaths = [f.lstrip('/') for f in self._filelist(p)]
                # TODO: also remove directories that aren't owned by anything else
                if filepaths:
                    logger.debug("removepkg %s: %ikb", p, self._getsize(*filepaths)/1024)
                    self.remove(*filepaths)
                else:
                    logger.debug("removepkg %s: no files to remove!", p)

        def run_pkg_transaction(self):
            '''
            run_pkg_transaction
              Actually install all the packages requested by previous 'installpkg'
              commands.
            '''
            try:
                logger.info("Checking dependencies")
                self.dbo.resolve()
            except dnf.exceptions.DepsolveError as e:
                logger.error("Dependency check failed: %s", e)
                raise
            logger.info("%d packages selected", len(self.dbo.transaction))
            if len(self.dbo.transaction) == 0:
                raise Exception("No packages in transaction")

            # If a debug repo has been included, write out a list of debuginfo packages
            self._write_debuginfo_log()

            pkgs_to_download = self.dbo.transaction.install_set
            logger.info("Downloading packages")
            progress = LoraxDownloadCallback()
            try:
                self.dbo.download_packages(pkgs_to_download, progress)
            except dnf.exceptions.DownloadError as e:
                logger.error("Failed to download the following packages: %s", e)
                raise

            logger.info("Preparing transaction from installation source")
            try:
                display = LoraxRpmCallback()
                self.dbo.do_transaction(display=display)
            except BaseException as e:
                logger.error("The transaction process has ended abruptly: %s", e)
                raise

            # Reset the package sack to pick up the installed packages
            self.dbo.reset(repos=False)
            self.dbo.fill_sack(load_system_repo=True, load_available_repos=False)

            # At this point dnf should know about the installed files. Double check that it really does.
            if len(self._filelist("anaconda-core")) == 0:
                raise Exception("Failed to reset dbo to installed package set")

        def removefrom(self, pkg, *globs):
            '''
            removefrom PKGGLOB [--allbut] FILEGLOB [FILEGLOB...]
              Remove all files matching the given file globs from the package
              (or packages) named.
              If '--allbut' is used, all the files from the given package(s) will
              be removed *except* the ones which match the file globs.

              Examples:
                removefrom usbutils /usr/bin/*
                removefrom xfsprogs --allbut /sbin/*
            '''
            cmd = "%s %s" % (pkg, " ".join(globs)) # save for later logging
            keepmatches = False
            if globs[0] == '--allbut':
                keepmatches = True
                globs = globs[1:]
            # get pkg filelist and find files that match the globs
            filelist = self._filelist(pkg)
            matches = set()
            for g in globs:
                globs_re = re.compile(fnmatch.translate(g))
                m = [f for f in filelist if globs_re.match(f)]
                if m:
                    matches.update(m)
                else:
                    logger.debug("removefrom %s %s: no files matched!", pkg, g)
            # are we removing the matches, or keeping only the matches?
            if keepmatches:
                remove_files = filelist.difference(matches)
            else:
                remove_files = matches
            # remove the files
            if remove_files:
                logger.debug("removefrom %s: removed %i/%i files, %ikb/%ikb", cmd,
                                 len(remove_files), len(filelist),
                                 self._getsize(*remove_files)/1024, self._getsize(*filelist)/1024)
                self.remove(*remove_files)
            else:
                logger.debug("removefrom %s: no files to remove!", cmd)

        def removekmod(self, *globs):
            '''
            removekmod GLOB [GLOB...] [--allbut] KEEPGLOB [KEEPGLOB...]
              Remove all files and directories matching the given file globs from the kernel
              modules directory.

              If '--allbut' is used, all the files from the modules will be removed *except*
              the ones which match the file globs. There must be at least one initial GLOB
              to search and one KEEPGLOB to keep. The KEEPGLOB is expanded to be *KEEPGLOB*
              so that it will match anywhere in the path.

              This only removes files from under /lib/modules/*/kernel/

              Examples:
                removekmod sound drivers/media drivers/hwmon drivers/video
                removekmod drivers/char --allbut virtio_console hw_random
            '''
            cmd = " ".join(globs)
            if "--allbut" in globs:
                idx = globs.index("--allbut")
                if idx == 0:
                    raise ValueError("removekmod needs at least one GLOB before --allbut")

                # Apply keepglobs anywhere they appear in the path
                keepglobs = globs[idx+1:]
                if len(keepglobs) == 0:
                    raise ValueError("removekmod needs at least one GLOB after --allbut")

                globs = globs[:idx]
            else:
                # Nothing to keep
                keepglobs = []

            filelist = set()
            for g in globs:
                for top_dir in rglob(self._out("/lib/modules/*/kernel/"+g)):
                    for root, _dirs, files in os.walk(top_dir):
                        filelist.update(root+"/"+f for f in files)

            # Remove anything matching keepglobs from the list
            matches = set()
            for g in keepglobs:
                globs_re = re.compile(fnmatch.translate("*"+g+"*"))
                m = [f for f in filelist if globs_re.match(f)]
                if m:
                    matches.update(m)
                else:
                    logger.debug("removekmod %s: no files matched!", g)
            remove_files = filelist.difference(matches)

            if remove_files:
                logger.debug("removekmod: removing %d files", len(remove_files))
                list(remove(f) for f in remove_files)
            else:
                logger.debug("removekmod %s: no files to remove!", cmd)

        def createaddrsize(self, addr, src, dest):
            '''
            createaddrsize INITRD_ADDRESS INITRD ADDRSIZE
              Create the initrd.addrsize file required in LPAR boot process.

              Examples:
                createaddrsize ${INITRD_ADDRESS} ${outroot}/${BOOTDIR}/initrd.img ${outroot}/${BOOTDIR}/initrd.addrsize
            '''
            addrsize = open(dest, "wb")
            addrsize_data = struct.pack(">iiii", 0, int(addr, 16), 0, os.stat(src).st_size)
            addrsize.write(addrsize_data)
            addrsize.close()

        def systemctl(self, cmd, *units):
            '''
            systemctl [enable|disable|mask] UNIT [UNIT...]
              Enable, disable, or mask the given systemd units.

              Examples:
                systemctl disable lvm2-monitor.service
                systemctl mask fedora-storage-init.service fedora-configure.service
            '''
            if cmd not in ('enable', 'disable', 'mask'):
                raise ValueError('unsupported systemctl cmd: %s' % cmd)
            if not units:
                logger.debug("systemctl: no units given for %s, ignoring", cmd)
                return
            self.mkdir("/run/systemd/system") # XXX workaround for systemctl bug
            systemctl = ['systemctl', '--root', self.outroot, '--no-reload', cmd]
            # When a unit doesn't exist systemd aborts the command. Run them one at a time.
            # XXX for some reason 'systemctl enable/disable' always returns 1
            for unit in units:
                try:
                    cmd = systemctl + [unit]
                    runcmd(cmd)
                except CalledProcessError:
                    pass

    class LiveTemplateRunner(TemplateRunner):
        """
        This class parses and executes a limited Lorax template. Sample usage:

          # install a bunch of packages
          runner = LiveTemplateRunner(dbo, templatedir, defaults)
          runner.run("live-install.tmpl")

          It is meant to be used with the live-install.tmpl which lists the per-arch
          pacages needed to build the live-iso output.
        """
        def __init__(self, dbo, fatalerrors=True, templatedir=None, defaults=None):
            self.dbo = dbo
            self.pkgs = []
            self.pkgnames = []

            super(LiveTemplateRunner, self).__init__(fatalerrors, templatedir, defaults)

        def installpkg(self, *pkgs):
            '''
            installpkg [--required|--optional] [--except PKGGLOB [--except PKGGLOB ...]] PKGGLOB [PKGGLOB ...]
              Request installation of all packages matching the given globs.
              Note that this is just a *request* - nothing is *actually* installed
              until the 'run_pkg_transaction' command is given.

              --required is now the default. If the PKGGLOB can be missing pass --optional
            '''
            if pkgs[0] == '--optional':
                pkgs = pkgs[1:]
                required = False
            elif pkgs[0] == '--required':
                pkgs = pkgs[1:]
                required = True
            else:
                required = True

            excludes = []
            while '--except' in pkgs:
                idx = pkgs.index('--except')
                if len(pkgs) == idx+1:
                    raise ValueError("installpkg needs an argument after --except")

                excludes.append(pkgs[idx+1])
                pkgs = pkgs[:idx] + pkgs[idx+2:]

            errors = False
            for p in pkgs:
                try:
                    # Start by using Subject to generate a package query, which will
                    # give us a query object similar to what dbo.install would select,
                    # minus the handling for multilib. This query may contain
                    # multiple arches. Pull the package names out of that, filter any
                    # that match the excludes patterns, and pass those names back to
                    # dbo.install to do the actual, arch and version and multilib
                    # aware, package selction.

                    # dnf queries don't have a concept of negative globs which is why
                    # the filtering is done the hard way.

                    pkgnames = [pkg for pkg in dnf.subject.Subject(p).get_best_query(self.dbo.sack).filter(latest=True)]
                    if not pkgnames:
                        raise dnf.exceptions.PackageNotFoundError("no package matched", p)

                    # Apply excludes to the name only
                    for exclude in excludes:
                        pkgnames = [pkg for pkg in pkgnames if not fnmatch.fnmatch(pkg.name, exclude)]

                    # Convert to a sorted NVR list for installation
                    pkgnvrs = sorted(["{}-{}-{}".format(pkg.name, pkg.version, pkg.release) for pkg in pkgnames])

                    # If the request is a glob, expand it in the log
                    if any(g for g in ['*','?','.'] if g in p):
                        logger.info("installpkg: %s expands to %s", p, ",".join(pkgnvrs))

                    self.pkgs.extend(pkgnvrs)
                    self.pkgnames.extend([pkg.name for pkg in pkgnames])
                except Exception as e: # pylint: disable=broad-except
                    logger.error("installpkg %s failed: %s", p, str(e))
                    errors = True

            if errors and required:
                raise Exception("Required installpkg failed.")