From 8eaad3bc5e0a9c65cf12a2997edec084abd82e30 Mon Sep 17 00:00:00 2001 From: "Brian C. Lane" Date: Fri, 15 Feb 2019 16:31:08 -0800 Subject: [PATCH] Move the run part of LoraxTemplateRunner into new TemplateRunner class This will make it easier to add a new subclass that only handles installpkg for use with livemedia-creator and lorax-composer iso creation. --- src/pylorax/ltmpl.py | 167 +++++++++++++++++++++++-------------------- 1 file changed, 91 insertions(+), 76 deletions(-) diff --git a/src/pylorax/ltmpl.py b/src/pylorax/ltmpl.py index 622e772a..e8fb5221 100644 --- a/src/pylorax/ltmpl.py +++ b/src/pylorax/ltmpl.py @@ -103,8 +103,83 @@ def rexists(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(object): +class LoraxTemplateRunner(TemplateRunner): ''' This class parses and executes Lorax templates. Sample usage: @@ -118,18 +193,6 @@ class LoraxTemplateRunner(object): 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)! - * 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. @@ -152,14 +215,11 @@ class LoraxTemplateRunner(object): self.inroot = inroot self.outroot = outroot self.dbo = dbo - self.fatalerrors = fatalerrors - self.templatedir = templatedir or "/usr/share/lorax" - self.templatefile = None - # some builtin methods - self.builtins = DataHolder(exists=lambda p: rexists(p, root=inroot), - glob=lambda g: list(rglob(g, root=inroot))) - self.defaults = defaults or {} + 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): @@ -210,51 +270,6 @@ class LoraxTemplateRunner(object): for pkg in debug_pkgs: f.write("%s\n" % pkg) - 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 - def install(self, srcglob, dest): ''' install SRC DEST @@ -265,7 +280,7 @@ class LoraxTemplateRunner(object): 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 @@ -321,7 +336,7 @@ class LoraxTemplateRunner(object): ''' mkdir DIR [DIR ...] Create the named DIR(s). Will create leading directories as needed. - + Example: mkdir /images ''' @@ -335,7 +350,7 @@ class LoraxTemplateRunner(object): 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@ ${product.version} /boot/grub.conf /boot/isolinux.cfg ''' @@ -353,9 +368,9 @@ class LoraxTemplateRunner(object): Append STRING (followed by a newline character) to FILE. Python character escape sequences ('\\n', '\\t', etc.) will be converted to the appropriate characters. - + Examples: - + append /etc/depmod.d/dd.conf "search updates built-in" append /etc/resolv.conf "" ''' @@ -368,7 +383,7 @@ class LoraxTemplateRunner(object): Add an item to the treeinfo data store. The given SECTION will have a new item added where KEY = ARG ARG ... - + Example: treeinfo images-${kernel.arch} boot.iso images/boot.iso ''' @@ -469,7 +484,7 @@ class LoraxTemplateRunner(object): ''' log MESSAGE Emit the given log message. Be sure to put it in quotes! - + Example: log "Reticulating splines, please wait..." ''' @@ -588,7 +603,7 @@ class LoraxTemplateRunner(object): ''' 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. @@ -653,7 +668,7 @@ class LoraxTemplateRunner(object): (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/* @@ -748,7 +763,7 @@ class LoraxTemplateRunner(object): ''' 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 ''' @@ -761,7 +776,7 @@ class LoraxTemplateRunner(object): ''' 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