Introduce support for jinja2-based templates.

.gitignore

@@ -1,4 +1,5 @@
 # Byte-compiled / optimized / DLL files
+__jinja__/
 __pycache__/
 *.py[cod]
 *$py.class

mig/lib/templates/__init__.py

@@ -0,0 +1,138 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+#
+# --- BEGIN_HEADER ---
+#
+# base - shared base helper functions
+# Copyright (C) 2003-2024  The MiG Project by the Science HPC Center at UCPH
+#
+# This file is part of MiG.
+#
+# MiG 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.
+#
+# MiG 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.
+#
+# -- END_HEADER ---
+#
+
+import errno
+from collections import ChainMap
+from jinja2 import meta as jinja2_meta, select_autoescape, Environment, \
+    FileSystemLoader, FileSystemBytecodeCache
+import os
+import weakref
+
+from mig.shared.compat import PY2
+from mig.shared.defaults import MIG_BASE
+
+
+class _BonundTemplate:
+    def __init__(self, template, template_args):
+        self.tmpl = template
+        self.args = template_args
+
+
+    def render(self):
+        return self.tmpl.render(**self.args)
+
+
+class _FormatContext:
+    def __init__(self, configuration):
+        self.output_format = None
+        self.configuration = configuration
+        self.script_map = {}
+        self.style_map = {}
+
+    def __getitem__(self, key):
+        return self.__dict__[key]
+
+    def __iter__(self):
+        return iter(self.__dict__)
+
+    def extend(self, template, template_args):
+        return _BonundTemplate(template, ChainMap(template_args, self))
+
+
+class TemplateStore:
+    def __init__(self, template_dirs, cache_dir=None, extra_globals=None):
+        assert cache_dir is not None
+
+        self._cache_dir = cache_dir
+        self._template_globals = extra_globals
+        self._template_environment = Environment(
+            loader=FileSystemLoader(template_dirs),
+            bytecode_cache=FileSystemBytecodeCache(cache_dir, '%s'),
+            autoescape=select_autoescape()
+        )
+
+    @property
+    def cache_dir(self):
+        return self._cache_dir
+
+    @property
+    def context(self):
+        return self._template_globals
+
+    def _get_template(self, template_fqname):
+        return self._template_environment.get_template(template_fqname)
+
+    def grab_template(self, template_name, template_group, output_format, template_globals=None, **kwargs):
+        template_fqname = "%s_%s.%s.jinja" % (
+            template_group, template_name, output_format)
+        return self._template_environment.get_template(template_fqname, globals=template_globals)
+
+    def list_templates(self):
+        return [t for t in self._template_environment.list_templates() if t.endswith('.jinja')]
+
+    def extract_variables(self, template_fqname):
+        template = self._template_environment.get_template(template_fqname)
+        with open(template.filename) as f:
+            template_source = f.read()
+        ast = self._template_environment.parse(template_source)
+        return jinja2_meta.find_undeclared_variables(ast)
+
+    @staticmethod
+    def populated(template_dirs, cache_dir=None, context=None):
+        assert cache_dir is not None
+
+        try:
+            os.mkdir(cache_dir)
+        except OSError as direxc:
+            if direxc.errno != errno.EEXIST:  # FileExistsError
+                raise
+
+        store = TemplateStore(
+            template_dirs, cache_dir=cache_dir, extra_globals=context)
+
+        for template_fqname in store.list_templates():
+            store._get_template(template_fqname)
+
+        return store
+
+
+def init_global_templates(configuration):
+    template_division = configuration.division(section_name="TEMPLATES")
+
+    _context = configuration.context()
+
+    try:
+        return configuration.context(namespace='templates')
+    except KeyError as exc:
+        pass
+
+    store = TemplateStore.populated(
+        [template_division.source_dir],
+        cache_dir=template_division.cache_dir,
+        context=_FormatContext(configuration)
+    )
+    return configuration.context_set(store, namespace='templates')

mig/lib/templates/__main__.py

@@ -0,0 +1,78 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+#
+# --- BEGIN_HEADER ---
+#
+# base - shared base helper functions
+# Copyright (C) 2003-2024  The MiG Project by the Science HPC Center at UCPH
+#
+# This file is part of MiG.
+#
+# MiG 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.
+#
+# MiG 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.
+#
+# -- END_HEADER ---
+#
+
+from types import SimpleNamespace
+import os
+import sys
+
+from mig.lib.templates import init_global_templates
+from mig.shared.conf import get_configuration_object
+
+
+def warn(message):
+    print(message, file=sys.stderr, flush=True)
+
+
+def main(args, _print=print):
+    configuration = get_configuration_object(config_file=args.config_file)
+    template_store = init_global_templates(configuration)
+
+    command = args.command
+    if command == 'show':
+        print(template_store.list_templates())
+    elif command == 'prime':
+        try:
+            os.mkdir(template_store.cache_dir)
+        except FileExistsError:
+            pass
+
+        for template_fqname in template_store.list_templates():
+            template_store._get_template(template_fqname)
+    elif command == 'vars':
+        for template_ref in template_store.list_templates():
+            _print("<%s>" % (template_ref,))
+            for var in template_store.extract_variables(template_ref):
+                _print("  {{%s}}" % (var,))
+            _print("</%s>" % (template_ref,))
+    else:
+        raise RuntimeError("unknown command: %s" % (command,))
+
+
+if __name__ == '__main__':
+    import argparse
+
+    parser = argparse.ArgumentParser()
+    parser.add_argument('-c', dest='config_file', default=None)
+    parser.add_argument('command')
+    args = parser.parse_args()
+
+    try:
+        main(args)
+        sys.exit(0)
+    except Exception as exc:
+        warn(str(exc))
+        sys.exit(1)

mig/shared/conf.py

@@ -32,6 +32,7 @@
 import os
 import sys
 
+from mig.shared.configuration import RuntimeConfiguration
 from mig.shared.defaults import MIG_ENV
 from mig.shared.fileio import unpickle
 
@@ -42,7 +43,6 @@ def get_configuration_object(config_file=None, skip_log=False,
     and disable_auth_log arguments are passed on to allow skipping the default
     log initialization and disabling auth log for unit tests.
     """
-    from mig.shared.configuration import Configuration
     if config_file:
         _config_file = config_file
     elif os.environ.get('MIG_CONF', None):
@@ -63,7 +63,7 @@ def get_configuration_object(config_file=None, skip_log=False,
         skip_log = True
         disable_auth_log = True
 
-    configuration = Configuration(_config_file, False, skip_log,
+    configuration = RuntimeConfiguration(_config_file, False, skip_log,
                                   disable_auth_log)
     return configuration