Source code for cobbler.templar

"""
Cobbler uses Cheetah templates for lots of stuff, but there's
some additional magic around that to deal with snippets/etc.
(And it's not spelled wrong!)
"""

from builtins import str
from builtins import object
import Cheetah
import functools
import os
import os.path
import pprint
import string

jinja2_available = False
try:
    import jinja2
    jinja2_available = True
except:
    """ FIXME: log a message here """
    pass

from .cexceptions import CX
from . import clogger
from .template_api import Template
from . import utils

major, minor, release = Cheetah.Version.split('.')[0:3]
fix_cheetah_class = (int(major), int(minor), int(release)) >= (2, 4, 2)


[docs]class Templar(object): def __init__(self, collection_mgr, logger=None): """ Constructor """ self.collection_mgr = None self.settings = None if collection_mgr: self.collection_mgr = collection_mgr self.settings = collection_mgr.settings() self.last_errors = [] if logger is None: logger = clogger.Logger() self.logger = logger
[docs] def check_for_invalid_imports(self, data): """ Ensure that Cheetah code is not importing Python modules that may allow for advanced priveledges by ensuring we whitelist the imports that we allow """ lines = data.split("\n") for line in lines: if line.find("#import") != -1: rest = line.replace("#import", "").replace(" ", "").strip() if self.settings and rest not in self.settings.cheetah_import_whitelist: raise CX("potentially insecure import in template: %s" % rest)
[docs] def render(self, data_input, search_table, out_path, subject=None, template_type=None): """ Render data_input back into a file. data_input is either a string or a filename search_table is a dict of metadata keys and values out_path if not-none writes the results to a file (though results are always returned) subject is a profile or system object, if available (for snippet eval) """ if not isinstance(data_input, str): raw_data = data_input.read() else: raw_data = data_input lines = raw_data.split('\n') if not template_type: # Assume we're using the default template type, if set in # the settinigs file or use cheetah as the last resort if self.settings and self.settings.default_template_type: template_type = self.settings.default_template_type else: template_type = "cheetah" if len(lines) > 0 and lines[0].find("#template=") == 0: # pull the template type out of the first line and then drop # it and rejoin them to pass to the template language template_type = lines[0].split("=")[1].strip().lower() del lines[0] raw_data = string.join(lines, "\n") if template_type == "cheetah": data_out = self.render_cheetah(raw_data, search_table, subject) elif template_type == "jinja2": if jinja2_available: data_out = self.render_jinja2(raw_data, search_table, subject) else: return "# ERROR: JINJA2 NOT AVAILABLE. Maybe you need to install python-jinja2?\n" else: return "# ERROR: UNSUPPORTED TEMPLATE TYPE (%s)" % str(template_type) # now apply some magic post-filtering that is used by cobbler import and some # other places. Forcing folks to double escape things would be very unwelcome. hp = search_table.get("http_port", "80") server = search_table.get("server", "server.example.org") if hp not in (80, '80'): repstr = "%s:%s" % (server, hp) else: repstr = server search_table["http_server"] = repstr for x in list(search_table.keys()): if type(x) == str: data_out = data_out.replace("@@%s@@" % str(x), str(search_table[str(x)])) # remove leading newlines which apparently breaks AutoYAST ? if data_out.startswith("\n"): data_out = data_out.lstrip() # if requested, write the data out to a file if out_path is not None: utils.mkdir(os.path.dirname(out_path)) fd = open(out_path, "w+") fd.write(data_out) fd.close() return data_out
[docs] def render_cheetah(self, raw_data, search_table, subject=None): """ Render data_input back into a file. data_input is either a string or a filename search_table is a dict of metadata keys and values (though results are always returned) subject is a profile or system object, if available (for snippet eval) """ self.check_for_invalid_imports(raw_data) # backward support for Cobbler's legacy (and slightly more readable) # template syntax. raw_data = raw_data.replace("TEMPLATE::", "$") # HACK: the autoinstall_meta field may contain nfs://server:/mount in which # case this is likely WRONG for automated installation files, which needs # the NFS directive instead. Do this to make the templates work. newdata = "" if "tree" in search_table and search_table["tree"].startswith("nfs://"): for line in raw_data.split("\n"): if line.find("--url") != -1 and line.find("url ") != -1: rest = search_table["tree"][6:] # strip off "nfs://" part try: (server, dir) = rest.split(":", 2) except: raise CX("Invalid syntax for NFS path given during import: %s" % search_table["tree"]) line = "nfs --server %s --dir %s" % (server, dir) # but put the URL part back in so koan can still see # what the original value was line += "\n" + "#url --url=%s" % search_table["tree"] newdata += line + "\n" raw_data = newdata # tell Cheetah not to blow up if it can't find a symbol for something raw_data = "#errorCatcher ListErrors\n" + raw_data table_copy = search_table.copy() # for various reasons we may want to call a module inside a template and pass # it all of the template variables. The variable "template_universe" serves # this purpose to make it easier to iterate through all of the variables without # using internal Cheetah variables search_table.update({ "template_universe": table_copy }) # now do full templating scan, where we will also templatify the snippet insertions t = Template(source=raw_data, searchList=[search_table], compilerSettings={'useStackFrame': False}) if fix_cheetah_class: t.SNIPPET = functools.partial(t.SNIPPET, t) t.read_snippet = functools.partial(t.read_snippet, t) try: data_out = t.respond() self.last_errors = t.errorCatcher().listErrors() if self.last_errors: self.logger.warning("errors were encountered rendering the template") self.logger.warning("\n" + pprint.pformat(self.last_errors)) except Exception as e: self.logger.error(utils.cheetah_exc(e)) raise CX("Error templating file, check cobbler.log for more details") return data_out
[docs] def render_jinja2(self, raw_data, search_table, subject=None): """ Render data_input back into a file. data_input is either a string or a filename search_table is a dict of metadata keys and values out_path if not-none writes the results to a file (though results are always returned) subject is a profile or system object, if available (for snippet eval) """ try: if self.settings and self.settings.jinja2_includedir: template = jinja2.Environment(loader=jinja2.FileSystemLoader(self.settings.jinja2_includedir)).from_string(raw_data) else: template = jinja2.Template(raw_data) data_out = template.render(search_table) except Exception as exc: self.logger.warning("errors were encountered rendering the template") self.logger.warning(exc.__str__()) data_out = "# EXCEPTION OCCURRED DURING JINJA2 TEMPLATE PROCESSING\n" return data_out