summaryrefslogtreecommitdiff
path: root/python
diff options
context:
space:
mode:
authorChristian Poessinger <christian@poessinger.com>2020-08-16 18:20:23 +0200
committerGitHub <noreply@github.com>2020-08-16 18:20:23 +0200
commit888163e95c89201ee28c0745508e1ba50c444164 (patch)
tree0ec9620463318ae65e21fdc478a2c617f62985af /python
parentb17b8a0129f42c757c1e9a740664406e8da3dd42 (diff)
parent3ec77c9c878939f8c6e4eca62c4a2cddfef20db1 (diff)
downloadvyos-1x-888163e95c89201ee28c0745508e1ba50c444164.tar.gz
vyos-1x-888163e95c89201ee28c0745508e1ba50c444164.zip
Merge pull request #510 from efficiosoft/vyos_template_rewrite
vyos.template: T2720: Rework vyos.template Python library
Diffstat (limited to 'python')
-rw-r--r--python/vyos/template.py163
-rw-r--r--python/vyos/util.py23
2 files changed, 119 insertions, 67 deletions
diff --git a/python/vyos/template.py b/python/vyos/template.py
index d9b0c749d..c88ab04a0 100644
--- a/python/vyos/template.py
+++ b/python/vyos/template.py
@@ -1,4 +1,4 @@
-# Copyright 2019 VyOS maintainers and contributors <maintainers@vyos.io>
+# Copyright 2019-2020 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
@@ -13,78 +13,131 @@
# 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 functools
import os
+from ipaddress import ip_network
from jinja2 import Environment
from jinja2 import FileSystemLoader
from vyos.defaults import directories
from vyos.util import chmod, chown, makedir
-# reuse the same Environment to improve performance
-_templates_env = {
- False: Environment(loader=FileSystemLoader(directories['templates'])),
- True: Environment(loader=FileSystemLoader(directories['templates']), trim_blocks=True),
-}
-_templates_mem = {
- False: {},
- True: {},
-}
-def vyos_address_from_cidr(text):
- """ Take an IPv4/IPv6 CIDR prefix and convert the network to an "address".
- Example:
- 192.0.2.0/24 -> 192.0.2.0, 2001:db8::/48 -> 2001:db8::
- """
- from ipaddress import ip_network
- return ip_network(text).network_address
+# Holds template filters registered via register_filter()
+_FILTERS = {}
-def vyos_netmask_from_cidr(text):
- """ Take an IPv4/IPv6 CIDR prefix and convert the prefix length to a "subnet mask".
- Example:
- 192.0.2.0/24 -> 255.255.255.0, 2001:db8::/48 -> ffff:ffff:ffff::
- """
- from ipaddress import ip_network
- return ip_network(text).netmask
-def render(destination, template, content, trim_blocks=False, formater=None, permission=None, user=None, group=None):
+# reuse Environments with identical trim_blocks setting to improve performance
+@functools.lru_cache(maxsize=2)
+def _get_environment(trim_blocks):
+ env = Environment(
+ # Don't check if template files were modified upon re-rendering
+ auto_reload=False,
+ # Cache up to this number of templates for quick re-rendering
+ cache_size=100,
+ loader=FileSystemLoader(directories["templates"]),
+ trim_blocks=trim_blocks,
+ )
+ env.filters.update(_FILTERS)
+ return env
+
+
+def register_filter(name, func=None):
+ """Register a function to be available as filter in templates under given name.
+
+ It can also be used as a decorator, see below in this module for examples.
+
+ :raise RuntimeError:
+ when trying to register a filter after a template has been rendered already
+ :raise ValueError: when trying to register a name which was taken already
"""
- 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)
+ if func is None:
+ return functools.partial(register_filter, name)
+ if _get_environment.cache_info().currsize:
+ raise RuntimeError(
+ "Filters can only be registered before rendering the first template"
+ )
+ if name in _FILTERS:
+ raise ValueError(f"A filter with name {name!r} was registered already")
+ _FILTERS[name] = func
+ return func
+
+
+def render_to_string(template, content, trim_blocks=False, formater=None):
+ """Render a template from the template directory, raise on any errors.
+
+ :param template: the path to the template relative to the template folder
+ :param content: the dictionary of variables to put into rendering context
+ :param trim_blocks: controls the trim_blocks jinja2 feature
+ :param formater:
+ if given, it has to be a callable the rendered string is passed through
+
+ The parsed template files are cached, so rendering the same file multiple times
+ does not cause as too much overhead.
+ If used everywhere, it could be changed to load the template from Python
+ environment variables from an importable Python module generated when the Debian
+ package is build (recovering the load time and overhead caused by having the
+ file out of the code).
"""
+ template = _get_environment(bool(trim_blocks)).get_template(template)
+ rendered = template.render(content)
+ if formater is not None:
+ rendered = formater(rendered)
+ return rendered
+
+
+def render(
+ destination,
+ template,
+ content,
+ trim_blocks=False,
+ formater=None,
+ permission=None,
+ user=None,
+ group=None,
+):
+ """Render a template from the template directory to a file, raise on any errors.
- # Create the directory if it does not exists
+ :param destination: path to the file to save the rendered template in
+ :param permission: permission bitmask to set for the output file
+ :param user: user to own the output file
+ :param group: group to own the output file
+
+ All other parameters are as for :func:`render_to_string`.
+ """
+ # Create the directory if it does not exist
folder = os.path.dirname(destination)
makedir(folder, user, group)
- # Setup a renderer for the given template
- # This is cached and re-used for performance
- if template not in _templates_mem[trim_blocks]:
- _env = _templates_env[trim_blocks]
- _env.filters['address_from_cidr'] = vyos_address_from_cidr
- _env.filters['netmask_from_cidr'] = vyos_netmask_from_cidr
- _templates_mem[trim_blocks][template] = _env.get_template(template)
+ # As we are opening the file with 'w', we are performing the rendering before
+ # calling open() to not accidentally erase the file if rendering fails
+ rendered = render_to_string(template, content, trim_blocks, formater)
- template = _templates_mem[trim_blocks][template]
+ # Write to file
+ with open(destination, "w") as file:
+ chmod(file.fileno(), permission)
+ chown(file.fileno(), user, group)
+ file.write(rendered)
- # 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)
- if formater:
- content = formater(content)
+##################################
+# Custom template filters follow #
+##################################
- # Write client config file
- with open(destination, 'w') as f:
- f.write(content)
- chmod(destination, permission)
- chown(destination, user, group)
+@register_filter("address_from_cidr")
+def vyos_address_from_cidr(text):
+ """ Take an IPv4/IPv6 CIDR prefix and convert the network to an "address".
+ Example:
+ 192.0.2.0/24 -> 192.0.2.0, 2001:db8::/48 -> 2001:db8::
+ """
+ return ip_network(text).network_address
+
+
+@register_filter("netmask_from_cidr")
+def vyos_netmask_from_cidr(text):
+ """ Take an IPv4/IPv6 CIDR prefix and convert the prefix length to a "subnet mask".
+ Example:
+ 192.0.2.0/24 -> 255.255.255.0, 2001:db8::/48 -> ffff:ffff:ffff::
+ """
+ return ip_network(text).netmask
diff --git a/python/vyos/util.py b/python/vyos/util.py
index c07fef599..d27a8a3e7 100644
--- a/python/vyos/util.py
+++ b/python/vyos/util.py
@@ -240,7 +240,8 @@ def chown(path, user, group):
if user is None or group is None:
return False
- if not os.path.exists(path):
+ # path may also be an open file descriptor
+ if not isinstance(path, int) and not os.path.exists(path):
return False
uid = getpwnam(user).pw_uid
@@ -250,7 +251,8 @@ def chown(path, user, group):
def chmod(path, bitmask):
- if not os.path.exists(path):
+ # path may also be an open file descriptor
+ if not isinstance(path, int) and not os.path.exists(path):
return
if bitmask is None:
return
@@ -261,28 +263,25 @@ def chmod_600(path):
""" make file only read/writable by owner """
from stat import S_IRUSR, S_IWUSR
- if os.path.exists(path):
- bitmask = S_IRUSR | S_IWUSR
- os.chmod(path, bitmask)
+ bitmask = S_IRUSR | S_IWUSR
+ chmod(path, bitmask)
def chmod_750(path):
""" make file/directory only executable to user and group """
from stat import S_IRUSR, S_IWUSR, S_IXUSR, S_IRGRP, S_IXGRP
- if os.path.exists(path):
- bitmask = S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP | S_IXGRP
- os.chmod(path, bitmask)
+ bitmask = S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP | S_IXGRP
+ chmod(path, bitmask)
def chmod_755(path):
""" make file executable by all """
from stat import S_IRUSR, S_IWUSR, S_IXUSR, S_IRGRP, S_IXGRP, S_IROTH, S_IXOTH
- if os.path.exists(path):
- bitmask = S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP | S_IXGRP | \
- S_IROTH | S_IXOTH
- os.chmod(path, bitmask)
+ bitmask = S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP | S_IXGRP | \
+ S_IROTH | S_IXOTH
+ chmod(path, bitmask)
def makedir(path, user=None, group=None):