facter2etcd.py

#!/usr/bin/env python3

import argparse
import etcd3gw
import platform
import shutil
import subprocess
import urllib.parse


class Facter2Etcd:
    _exe = None
    _instance = None

    def __init__(self):
       raise RuntimeError("Use instance()")

    @classmethod
    def instance(cls):
       if cls._instance is None:
           cls._instance = cls.__new__(cls)
       return cls._instance

    @property
    def exe(self) -> str:
       if not self._exe:
           self._exe = shutil.which("facter")
           if not self._exe:
               raise RuntimeError("facter is not available")
       return self._exe

    def run(self, host, port, proto, base_key):
        cmd = [self.exe, '-j']
        proc = subprocess.Popen(cmd, stdout=subprocess.PIPE, universal_newlines=True)
        out, err = proc.communicate()
        rc = proc.returncode
        if rc != 0:
            raise RuntimeError(f"Failure running facter: {err}")
        k = "/".join([base_key, 'facter'])

        c = etcd3gw.client(host=host, port=port, protocol=proto)
        if not c.put(k, out):
            raise RuntimeError(f"Uploading data to {k} failed.")
        print(f"Success! Data uploaded to {k}")


if __name__ == "__main__":
    obj = Facter2Etcd.instance()
    parser = argparse.ArgumentParser(
        description="Utility to push facter facts to etcd")

    parser.add_argument('--etcd-uri', default='http://127.0.0.1:2379', help='URI to the etcd gateway')
    parser.add_argument('--key-prefix', default=('/' + platform.uname()[1]), help='etcd key prefix')
    args = parser.parse_args()
    uri = urllib.parse.urlparse(args.etcd_uri)

    obj.run(uri.hostname, uri.port, uri.scheme, args.key_prefix)