Mini Shell

"""
Support for nginx
"""

import re
import urllib.request

import salt.utils.decorators as decorators
import salt.utils.path


# Cache the output of running which('nginx') so this module
# doesn't needlessly walk $PATH looking for the same binary
# for nginx over and over and over for each function herein
@decorators.memoize
def __detect_os():
    return salt.utils.path.which("nginx")


def __virtual__():
    """
    Only load the module if nginx is installed
    """
    if __detect_os():
        return True
    return (
        False,
        "The nginx execution module cannot be loaded: nginx is not installed.",
    )


def version():
    """
    Return server version from nginx -v

    CLI Example:

    .. code-block:: bash

        salt '*' nginx.version
    """
    cmd = f"{__detect_os()} -v"
    out = __salt__["cmd.run"](cmd).splitlines()
    ret = out[0].rsplit("/", maxsplit=1)
    return ret[-1]


def build_info():
    """
    Return server and build arguments

    CLI Example:

    .. code-block:: bash

        salt '*' nginx.build_info
    """
    ret = {"info": []}
    out = __salt__["cmd.run"](f"{__detect_os()} -V")

    for i in out.splitlines():
        if i.startswith("configure argument"):
            ret["build arguments"] = re.findall(r"(?:[^\s]*'.*')|(?:[^\s]+)", i)[2:]
            continue

        ret["info"].append(i)

    return ret


def configtest():
    """
    test configuration and exit

    CLI Example:

    .. code-block:: bash

        salt '*' nginx.configtest
    """
    ret = {}

    cmd = f"{__detect_os()} -t"
    out = __salt__["cmd.run_all"](cmd)

    if out["retcode"] != 0:
        ret["comment"] = "Syntax Error"
        ret["stderr"] = out["stderr"]
        ret["result"] = False

        return ret

    ret["comment"] = "Syntax OK"
    ret["stdout"] = out["stderr"]
    ret["result"] = True

    return ret


def signal(signal=None):
    """
    Signals nginx to start, reload, reopen or stop.

    CLI Example:

    .. code-block:: bash

        salt '*' nginx.signal reload
    """
    valid_signals = ("start", "reopen", "stop", "quit", "reload")

    if signal not in valid_signals:
        return

    # Make sure you use the right arguments
    if signal == "start":
        arguments = ""
    else:
        arguments = f" -s {signal}"
    cmd = __detect_os() + arguments
    out = __salt__["cmd.run_all"](cmd)

    # A non-zero return code means fail
    if out["retcode"] and out["stderr"]:
        ret = out["stderr"].strip()
    # 'nginxctl configtest' returns 'Syntax OK' to stderr
    elif out["stderr"]:
        ret = out["stderr"].strip()
    elif out["stdout"]:
        ret = out["stdout"].strip()
    # No output for something like: nginxctl graceful
    else:
        ret = f'Command: "{cmd}" completed successfully!'
    return ret


def status(url="http://127.0.0.1/status"):
    """
    Return the data from an Nginx status page as a dictionary.
    http://wiki.nginx.org/HttpStubStatusModule

    url
        The URL of the status page. Defaults to 'http://127.0.0.1/status'

    CLI Example:

    .. code-block:: bash

        salt '*' nginx.status
    """
    resp = urllib.request.urlopen(url)
    status_data = resp.read()
    resp.close()

    lines = status_data.splitlines()
    if not len(lines) == 4:
        return
    # "Active connections: 1 "
    active_connections = lines[0].split()[2]
    # "server accepts handled requests"
    # "  12 12 9 "
    accepted, handled, requests = lines[2].split()
    # "Reading: 0 Writing: 1 Waiting: 0 "
    _, reading, _, writing, _, waiting = lines[3].split()
    return {
        "active connections": int(active_connections),
        "accepted": int(accepted),
        "handled": int(handled),
        "requests": int(requests),
        "reading": int(reading),
        "writing": int(writing),
        "waiting": int(waiting),
    }