BotZ/api/conf.py

# -*- encoding: utf-8 -*-
import os
from pprint import pprint
import typing as T

import yaml

from api import DEBUG, BASE_URI


def read_conf(path: T.Optional[T.Text]) -> T.Dict:
    """
    Read the configuration from the provided path.
    Such configuration may provide the following information:
    ---
    base_uri: <base uri of the target instance>
    debug: <bool, set debug on, defaults to false>
    headless: <bool, use headless mode, defaults to true>
    log:
        level: <may be DEBUG, INFO, WARN, ..., defaults at INFO>
        syslog: <bool, whether to redirect to standard syslog, defaults to false>
    http:
        bind_addr: <a list of addresses  to bind to>
        port: <int, the port to bind to>
        cookie_name: <defaults to BOTZ_SESSION>
        cookie_secure: <bool, whether to set Secure cookie flag, defaults to true>
        session_timeout: <int, the expiration time of the session ins secs, defaults to 300>
        cors_allow: <an optional single allowed Cross Origin domain>
    """
    if path is None:
        path = seek_path()
    if path is not None:
        with open(path) as f:
            conf = yaml.safe_load(f)
    else:
        conf = {}
    if "base_uri" not in conf:
        if BASE_URI is None:
            raise RuntimeError("Missing base_uri")
        conf["base_uri"] = BASE_URI
    if "debug" not in conf:
        conf["debug"] = DEBUG
    if "headless" not in conf:
        conf["headless"] = True
    conf = validate_log_conf(conf)
    conf = validate_http_log(conf)
    pprint(conf)
    return conf


def seek_path() -> T.Optional[T.Text]:
    """
    Seeks the path to a config file, in the following order:
     - $BOTZ_CONFIG
     - $PWD/.botz.yaml
     - ~/.botz.yaml
     - /etc/botz/conf.yaml
    """
    paths = [
        os.path.join(os.path.curdir, ".botz.yaml"),
        os.path.expanduser("~/.botz.yaml"),
        "/etc/botz/conf.yaml",
    ]
    env = os.environ.get("BOTZ_CONFIG")
    if env is not None:
        paths.insert(0, env)
    for path in paths:
        if os.path.exists(path):
            return path
    return None


def validate_log_conf(conf: T.Dict[T.Text, T.Any]) -> T.Dict[T.Text, T.Any]:
    if "log" not in conf:
        conf["log"] = {}
    if conf["log"].get("level") is None:
        conf["log"]["level"] = "INFO"
    if conf["log"].get("syslog") is None:
        conf["log"]["syslog"] = False
    return conf


def validate_http_log(conf: T.Dict[T.Text, T.Any]) -> T.Dict[T.Text, T.Any]:
    if "http" not in conf:
        conf["http"] = {}
    if conf["http"].get("bind_addr") is None:
        conf["http"]["bind_addr"] = ["127.0.0.1"]
    if conf["http"].get("port") is None:
        conf["http"]["port"] = 3003
    if conf["http"].get("cookie_name") is None:
        conf["http"]["cookie_name"] = "BOTZ_SESSION"
    if conf["http"].get("cookie_secure") is None:
        conf["http"]["cookie_secure"] = True
    if conf["http"].get("session_timeout") is None:
        conf["http"]["session_timeout"] = 300
    elif isinstance(conf["http"]["session_timeout"], str):
        conf["http"]["session_timeout"] = int(conf["http"]["session_timeout"])

    return conf