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author | Stuart Mackie <wsmackie@juniper.net> | 2016-11-22 14:00:39 -0800 |
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committer | Stuart Mackie <wsmackie@juniper.net> | 2016-11-22 14:00:39 -0800 |
commit | 5de4c9f0c126b984da72128a3ca084eda6b4087a (patch) | |
tree | 0be55aa0809cc395e45baeae63db660b4e72fe83 /charms/trusty/cassandra/hooks/charmhelpers/core/templating.py | |
parent | f02da72993eb8e5a34ed049bad442c6d6db4701a (diff) |
Add local cassandra charm from Tony Liu's machine
Change-Id: I56478233f7498861f95a0c12be983f9a1307853e
Signed-off-by: Stuart Mackie <wsmackie@juniper.net>
Diffstat (limited to 'charms/trusty/cassandra/hooks/charmhelpers/core/templating.py')
-rw-r--r-- | charms/trusty/cassandra/hooks/charmhelpers/core/templating.py | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/charms/trusty/cassandra/hooks/charmhelpers/core/templating.py b/charms/trusty/cassandra/hooks/charmhelpers/core/templating.py new file mode 100644 index 0000000..d2d8eaf --- /dev/null +++ b/charms/trusty/cassandra/hooks/charmhelpers/core/templating.py @@ -0,0 +1,81 @@ +# Copyright 2014-2015 Canonical Limited. +# +# This file is part of charm-helpers. +# +# charm-helpers is free software: you can redistribute it and/or modify +# it under the terms of the GNU Lesser General Public License version 3 as +# published by the Free Software Foundation. +# +# charm-helpers 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 Lesser General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with charm-helpers. If not, see <http://www.gnu.org/licenses/>. + +import os + +from charmhelpers.core import host +from charmhelpers.core import hookenv + + +def render(source, target, context, owner='root', group='root', + perms=0o444, templates_dir=None, encoding='UTF-8', template_loader=None): + """ + Render a template. + + The `source` path, if not absolute, is relative to the `templates_dir`. + + The `target` path should be absolute. It can also be `None`, in which + case no file will be written. + + The context should be a dict containing the values to be replaced in the + template. + + The `owner`, `group`, and `perms` options will be passed to `write_file`. + + If omitted, `templates_dir` defaults to the `templates` folder in the charm. + + The rendered template will be written to the file as well as being returned + as a string. + + Note: Using this requires python-jinja2; if it is not installed, calling + this will attempt to use charmhelpers.fetch.apt_install to install it. + """ + try: + from jinja2 import FileSystemLoader, Environment, exceptions + except ImportError: + try: + from charmhelpers.fetch import apt_install + except ImportError: + hookenv.log('Could not import jinja2, and could not import ' + 'charmhelpers.fetch to install it', + level=hookenv.ERROR) + raise + apt_install('python-jinja2', fatal=True) + from jinja2 import FileSystemLoader, Environment, exceptions + + if template_loader: + template_env = Environment(loader=template_loader) + else: + if templates_dir is None: + templates_dir = os.path.join(hookenv.charm_dir(), 'templates') + template_env = Environment(loader=FileSystemLoader(templates_dir)) + try: + source = source + template = template_env.get_template(source) + except exceptions.TemplateNotFound as e: + hookenv.log('Could not load template %s from %s.' % + (source, templates_dir), + level=hookenv.ERROR) + raise e + content = template.render(context) + if target is not None: + target_dir = os.path.dirname(target) + if not os.path.exists(target_dir): + # This is a terrible default directory permission, as the file + # or its siblings will often contain secrets. + host.mkdir(os.path.dirname(target), owner, group, perms=0o755) + host.write_file(target, content.encode(encoding), owner, group, perms) + return content |