hosts

#!/usr/bin/env python3


from sys import stdout, exit
from json import dump
from yaml import load, CLoader
import subprocess as sp


def main():
    """ dump inventory return as json """
    dump(inventory(), fp=stdout, indent=4)


def group_name(name):

    if name in ["master", "node"]:
        return "kube-{}".format(name)

    return "defaults"


def inventory():
    " generate ansible inventory "

    data = {}
    meta = meta_defaults()

    for host, settings in vagrant_ssh_config().items():

        # updating group
        group = group_name(host.split("-")[0])
        hosts = data.get(group, [])
        hosts.append(host)
        data.update({group: hosts})

        # host meta
        meta.update({host: dict(transform(settings), **meta.get(host, {}))})

    # additional groups

    data.update({"etcd": data.get("kube-master", [])})
    data.update({"k8s-cluster": data.get("kube-master", []) + data.get("kube-node", [])})
    data.update({"k8s-cluster": data.get("kube-master", []) + data.get("kube-node", [])})


    data.update({"_meta": {"hostvars": meta}})

    return data


def meta_defaults():
    """ reads yaml generated for hosts - to emulate kubespray"""
    try:
        with open(".hosts.yml") as f:
            meta = load(f, Loader=CLoader)
    except FileNotFoundError:
        return {}
    finally:
        meta = {
            host: {option[1:]: value for option, value in items.items()}
            for host, items in meta.items()
        }
    return meta


def transform(data):
    """
    transform data we got from ssh config into meaningful for ansible structure
    """
    structured = {}

    structured["ansible_port"] = data["Port"]
    structured["ansible_host"] = data["HostName"]
    structured["ansible_user"] = data["User"]
    structured["ansible_private_key_file"] = data["IdentityFile"]

    structured["ansible_ssh_common_args"] = "  ".join(
        [
            "-o StrictHostKeyChecking=no",
            "-o UserKnownHostsFile=/dev/null",
            "-o ControlMaster=auto",
            "-o ControlPersist=30m",
            "-o ConnectionAttempts=100",
        ]
    )

    return structured


def vagrant_ssh_config():
    """ Return output of the vagrant ssh-config as dictionaty """
    proc = sp.Popen("vagrant ssh-config", stdout=sp.PIPE, stderr=sp.PIPE, shell=True)
    out, _ = proc.communicate()

    hosts = {}
    new_line = True  # new block
    for line in out.decode().split("\n"):

        if new_line is True:
            hostname = line.replace("Host ", "")
            new_line = False
        elif len(line) == 0:
            new_line = True
        else:
            data = line[2:].split(" ")

            host = hosts.get(hostname, {})
            host.update({data[0]: " ".join(data[1:])})
            hosts.update({hostname: host})

    return hosts


if __name__ == "__main__":
    exit(main())