https://github.com/openstack/os-apply-config
Apply configuration from cloud metadata. Mirror of code maintained at opendev.org.
https://github.com/openstack/os-apply-config
Last synced: about 1 year ago
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Apply configuration from cloud metadata. Mirror of code maintained at opendev.org.
- Host: GitHub
- URL: https://github.com/openstack/os-apply-config
- Owner: openstack
- License: apache-2.0
- Created: 2013-08-18T02:03:41.000Z (almost 13 years ago)
- Default Branch: master
- Last Pushed: 2024-10-19T15:39:47.000Z (over 1 year ago)
- Last Synced: 2025-03-31T08:09:29.421Z (over 1 year ago)
- Language: Python
- Homepage: https://opendev.org/openstack/os-apply-config
- Size: 349 KB
- Stars: 51
- Watchers: 10
- Forks: 18
- Open Issues: 0
-
Metadata Files:
- Readme: README.rst
- License: LICENSE
Awesome Lists containing this project
README
========================
Team and repository tags
========================
.. image:: https://governance.openstack.org/tc/badges/os-apply-config.svg
:target: https://governance.openstack.org/tc/reference/tags/index.html
.. Change things from this point on
===============
os-apply-config
===============
----------------------------------------------
Apply configuration from cloud metadata (JSON)
----------------------------------------------
What does it do?
================
It turns metadata from one or more JSON files like this::
{"keystone": {"database": {"host": "127.0.0.1", "user": "keystone", "password": "foobar"}}}
into service config files like this::
[sql]
connection = mysql://keystone:foobar@127.0.0.1/keystone
...other settings...
Usage
=====
Just pass it the path to a directory tree of templates::
sudo os-apply-config -t /home/me/my_templates
By default it will read config files according to the contents of
the file `/var/lib/os-collect-config/os_config_files.json`. In
order to remain backward compatible it will also fall back to
/var/run/os-collect-config/os_config_files.json, but the fallback
path is deprecated and will be removed in a later release. The main
path can be changed with the command line switch `--os-config-files`,
or the environment variable `OS_CONFIG_FILES_PATH`. The list can
also be overridden with the environment variable `OS_CONFIG_FILES`.
If overriding with `OS_CONFIG_FILES`, the paths are expected to be colon,
":", separated. Each json file referred to must have a mapping as their
root structure. Keys in files mentioned later in the list will override
keys in earlier files from this list. For example::
OS_CONFIG_FILES=/tmp/ec2.json:/tmp/cfn.json os-apply-config
This will read `ec2.json` and `cfn.json`, and if they have any
overlapping keys, the value from `cfn.json` will be used. That will
populate the tree for any templates found in the template path. See
https://opendev.org/openstack/os-collect-config for a
program that will automatically collect data and populate this list.
You can also override `OS_CONFIG_FILES` with the `--metadata` command
line option, specifying it multiple times instead of colon separating
the list.
`os-apply-config` will also always try to read metadata in the old
legacy paths first to populate the tree. These paths can be changed
with `--fallback-metadata`.
Templates
=========
The template directory structure should mimic a root filesystem, and
contain templates for only those files you want configured. For
example::
~/my_templates$ tree
.
+-- etc
+-- keystone
| +-- keystone.conf
+-- mysql
+-- mysql.conf
An example tree can be found `here `_.
If a template is executable it will be treated as an *executable
template*. Otherwise, it will be treated as a *mustache template*.
Mustache Templates
------------------
If you don't need any logic, just some string substitution, use a
mustache template.
Metadata settings are accessed with dot ('.') notation::
[sql]
connection = mysql://{{keystone.database.user}}:{{keystone.database.password}}@{{keystone.database.host}}/keystone
Executable Templates
--------------------
Configuration requiring logic is expressed in executable templates.
An executable template is a script which accepts configuration as a
JSON string on standard in, and writes a config file to standard out.
The script should exit non-zero if it encounters a problem, so that
os-apply-config knows what's up.
The output of the script will be written to the path corresponding to
the executable template's path in the template tree::
#!/usr/bin/env ruby
require 'json'
params = JSON.parse STDIN.read
puts "connection = mysql://#{c['keystone']['database']['user']}:#{c['keystone']['database']['password']}@#{c['keystone']['database']['host']}/keystone"
You could even embed mustache in a heredoc, and use that::
#!/usr/bin/env ruby
require 'json'
require 'mustache'
params = JSON.parse STDIN.read
template = <<-eos
[sql]
connection = mysql://{{keystone.database.user}}:{{keystone.database.password}}@{{keystone.database.host}}/keystone
[log]
...
eos
# tweak params here...
puts Mustache.render(template, params)
Quick Start
===========
::
# install it
sudo pip install -U git+https://opendev.org/openstack/os-apply-config.git
# grab example templates
git clone https://opendev.org/openstack/tripleo-image-elements /tmp/config
# run it
os-apply-config -t /tmp/config/elements/nova/os-apply-config/ -m /tmp/config/elements/seed-stack-config/config.json -o /tmp/config_output