pyconfd is like confd but written in python. Instead of plaintext configuration files, use python to write a tiny bit of code to query anything, which is then used to render a jinja2 template.
installation
pip install pyconfdsetup
# store python plugins here
mkdir -p /etc/pyconfd/conf.d/
# store jinja templates here
mkdir -p /etc/pyconfd/templates/Also, make sure that pyconfd is launched.
usage
Launch pyconfd directly:
pyconfdAt the moment, there is no daemon mode. Users of supervisord can write a supervisor config file like:
[program:pyconfd]
command=pyconfd
numprocs=1
numprocs_start=0
priority=30
autostart=true
autorestart=unexpected
startsecs=30
startretries=10
exitcodes=0,2
stopsignal=TERM
stopwaitsecs=10
directory=/
user=root
redirect_stderr=false
stdout_logfile=/data/log/supervisor/pyconfd.out
stdout_logfile_maxbytes=1MB
stdout_logfile_backups=10
stderr_logfile=/data/log/supervisor/pyconfd.err
stderr_logfile_maxbytes=1MB
stderr_logfile_backups=10
plugin example
Check out the examples. Basically put this in in a .py file in /etc/pyconfd/conf.d/ and write something like:
import pyconfd
import random
class BashPlugin(pyconfd.Plugin):
# filename of template from /etc/pyconf.d/templates/
src = "bash.cfg.tmpl"
# where to dump the generated config file
dest = "/tmp/bash.cfg"
# force reload of daemon, consider using supervisordctl
reload_cmd = "bash -c 'exit'"
def get(self):
return {"number": random.randrange(1, 101)}And the jinja template bash.cfg.tmpl can look like:
echo "The number is: {{ number }}"
real-world plugins
The plugin's "get" method can be written to do whatever. I often use it with consul like with consulate or pyconsul. Others may prefer to query etcd.
consulate
Extract a list of servers running a certain service, and their IP addresses.
import pyconfd
import consulate
class HAProxy(pyconfd.Plugin):
def get(self):
"""
Get relevant variables from consul.
:rtype: dict
"""
data = {"servers": {}}
session = consulate.Consulate()
services = session.catalog.services().keys()
for service in services:
data["servers"][service] = []
servers = session.catalog.service(service)
for server in servers:
ip_address = server["Address"]
data["servers"][service].append(ip_address)
return datafuture work
- daemon mode
- tests
- Switch away from gevent.sleep and use consul hooks to trigger config updates. This will deprecate most of this library.
license
BSD
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