diff options
| -rw-r--r-- | python/vyos/defaults.py | 1 | ||||
| -rw-r--r-- | python/vyos/template.py | 55 |
2 files changed, 56 insertions, 0 deletions
diff --git a/python/vyos/defaults.py b/python/vyos/defaults.py index a2ad142bc..88894674f 100644 --- a/python/vyos/defaults.py +++ b/python/vyos/defaults.py @@ -21,6 +21,7 @@ directories = { "current": "/opt/vyatta/etc/config-migrate/current", "migrate": "/opt/vyatta/etc/config-migrate/migrate", "log": "/var/log/vyatta", + "templates": "/usr/share/vyos/templates/" } cfg_group = 'vyattacfg' diff --git a/python/vyos/template.py b/python/vyos/template.py new file mode 100644 index 000000000..e559120c0 --- /dev/null +++ b/python/vyos/template.py @@ -0,0 +1,55 @@ +# Copyright 2019 VyOS maintainers and contributors <maintainers@vyos.io> +# +# This library is free software; you can redistribute it and/or +# modify it under the terms of the GNU Lesser General Public +# License as published by the Free Software Foundation; either +# version 2.1 of the License, or (at your option) any later version. +# +# This library 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 this library. If not, see <http://www.gnu.org/licenses/>. + +import os + +from jinja2 import Environment +from jinja2 import FileSystemLoader + +from vyos.defaults import directories + + +# reuse the same Environment to improve performance +_templates_env = Environment(loader=FileSystemLoader(directories['templates'])) +_templates_mem = {} + +def render(destination, template, content): + """ + render a template from the template directory, it will raise on any errors + destination: the file where the rendered template must be saved + template: the path to the template relative to the template folder + content: the dictionary to use to render the template + + This classes cache the renderer, so rendering the same file multiple time + does not cause as too much overhead. If use everywhere, it could be changed + and load the template from python environement variables from an import + python module generated when the debian package is build + (recovering the load time and overhead caused by having the file out of the code) + """ + + # Setup a renderer for the given template + # This is cached and re-used for performance + if template not in _templates_mem: + _templates_mem[template] = _templates_env.get_template(template) + template = _templates_mem[template] + + # As we are opening the file with 'w', we are performing the rendering + # before calling open() to not accidentally erase the file if the + # templating fails + content = template.render(content) + + # Write client config file + with open(destination, 'w') as f: + f.write(content) |