Mini Shell

"""
Top level package command wrapper, used to translate the os detected by grains
to the correct service manager

.. important::
    If you feel that Salt should be using this module to manage services on a
    minion, and it is using a different module (or gives an error similar to
    *'service.start' is not available*), see :ref:`here
    <module-provider-override>`.
"""

import fnmatch
import logging
import re

import salt.utils.odict as odict
import salt.utils.systemd

# Set up logging
log = logging.getLogger(__name__)

# Define the module's virtual name
__virtualname__ = "service"

# Define the module's function aliases
__func_alias__ = {"reload_": "reload"}


def __virtual__():
    """
    Only work on systems which default to OpenRC
    """
    if __grains__["os"] == "Gentoo" and not salt.utils.systemd.booted(__context__):
        return __virtualname__
    if __grains__["os"] == "Alpine":
        return __virtualname__
    return (
        False,
        "The gentoo_service execution module cannot be loaded: "
        "only available on Gentoo/Open-RC systems.",
    )


def _ret_code(cmd, ignore_retcode=False):
    log.debug("executing [%s]", cmd)
    sts = __salt__["cmd.retcode"](
        cmd, python_shell=False, ignore_retcode=ignore_retcode
    )
    return sts


def _list_services():
    return __salt__["cmd.run"]("rc-update -v show").splitlines()


def _get_service_list(include_enabled=True, include_disabled=False):
    enabled_services = dict()
    disabled_services = set()
    lines = _list_services()
    for line in lines:
        if "|" not in line:
            continue
        service = [l.strip() for l in line.split("|")]
        # enabled service should have runlevels
        if service[1]:
            if include_enabled:
                enabled_services.update({service[0]: sorted(service[1].split())})
            continue
        # in any other case service is disabled
        if include_disabled:
            disabled_services.update({service[0]: []})
    return enabled_services, disabled_services


def _enable_delta(name, requested_runlevels):
    all_enabled = get_enabled()
    current_levels = set(all_enabled[name] if name in all_enabled else [])
    enabled_levels = requested_runlevels - current_levels
    disabled_levels = current_levels - requested_runlevels
    return enabled_levels, disabled_levels


def _disable_delta(name, requested_runlevels):
    all_enabled = get_enabled()
    current_levels = set(all_enabled[name] if name in all_enabled else [])
    return current_levels & requested_runlevels


def _service_cmd(*args):
    return "/etc/init.d/{} {}".format(args[0], " ".join(args[1:]))


def _enable_disable_cmd(name, command, runlevels=()):
    return "rc-update {} {} {}".format(
        command, name, " ".join(sorted(runlevels))
    ).strip()


def get_enabled():
    """
    Return a list of service that are enabled on boot

    CLI Example:

    .. code-block:: bash

        salt '*' service.get_enabled
    """
    (enabled_services, disabled_services) = _get_service_list()
    return odict.OrderedDict(enabled_services)


def get_disabled():
    """
    Return a set of services that are installed but disabled

    CLI Example:

    .. code-block:: bash

        salt '*' service.get_disabled
    """
    (enabled_services, disabled_services) = _get_service_list(
        include_enabled=False, include_disabled=True
    )
    return sorted(disabled_services)


def available(name):
    """
    Returns ``True`` if the specified service is available, otherwise returns
    ``False``.

    CLI Example:

    .. code-block:: bash

        salt '*' service.available sshd
    """
    (enabled_services, disabled_services) = _get_service_list(
        include_enabled=True, include_disabled=True
    )
    return name in enabled_services or name in disabled_services


def missing(name):
    """
    The inverse of service.available.
    Returns ``True`` if the specified service is not available, otherwise returns
    ``False``.

    CLI Example:

    .. code-block:: bash

        salt '*' service.missing sshd
    """
    return not available(name)


def get_all():
    """
    Return all available boot services

    CLI Example:

    .. code-block:: bash

        salt '*' service.get_all
    """
    (enabled_services, disabled_services) = _get_service_list(
        include_enabled=True, include_disabled=True
    )
    enabled_services.update({s: [] for s in disabled_services})
    return odict.OrderedDict(enabled_services)


def start(name):
    """
    Start the specified service

    CLI Example:

    .. code-block:: bash

        salt '*' service.start <service name>
    """
    cmd = _service_cmd(name, "start")
    return not _ret_code(cmd)


def stop(name):
    """
    Stop the specified service

    CLI Example:

    .. code-block:: bash

        salt '*' service.stop <service name>
    """
    cmd = _service_cmd(name, "stop")
    return not _ret_code(cmd)


def restart(name):
    """
    Restart the named service

    CLI Example:

    .. code-block:: bash

        salt '*' service.restart <service name>
    """
    cmd = _service_cmd(name, "restart")
    return not _ret_code(cmd)


def reload_(name):
    """
    Reload the named service

    CLI Example:

    .. code-block:: bash

        salt '*' service.reload <service name>
    """
    cmd = _service_cmd(name, "reload")
    return not _ret_code(cmd)


def zap(name):
    """
    Resets service state

    CLI Example:

    .. code-block:: bash

        salt '*' service.zap <service name>
    """
    cmd = _service_cmd(name, "zap")
    return not _ret_code(cmd)


def status(name, sig=None):
    """
    Return the status for a service.
    If the name contains globbing, a dict mapping service name to True/False
    values is returned.

    .. versionchanged:: 2018.3.0
        The service name can now be a glob (e.g. ``salt*``)

    Args:
        name (str): The name of the service to check
        sig (str): Signature to use to find the service via ps

    Returns:
        bool: True if running, False otherwise
        dict: Maps service name to True if running, False otherwise

    CLI Example:

    .. code-block:: bash

        salt '*' service.status <service name> [service signature]
    """
    if sig:
        return bool(__salt__["status.pid"](sig))

    contains_globbing = bool(re.search(r"\*|\?|\[.+\]", name))
    if contains_globbing:
        services = fnmatch.filter(get_all(), name)
    else:
        services = [name]
    results = {}
    for service in services:
        cmd = _service_cmd(service, "status")
        results[service] = not _ret_code(cmd, ignore_retcode=True)
    if contains_globbing:
        return results
    return results[name]


def enable(name, **kwargs):
    """
    Enable the named service to start at boot

    CLI Example:

    .. code-block:: bash

        salt '*' service.enable <service name> <runlevels=single-runlevel>
        salt '*' service.enable <service name> <runlevels=[runlevel1,runlevel2]>
    """
    if "runlevels" in kwargs:
        requested_levels = set(
            kwargs["runlevels"]
            if isinstance(kwargs["runlevels"], list)
            else [kwargs["runlevels"]]
        )
        enabled_levels, disabled_levels = _enable_delta(name, requested_levels)
        commands = []
        if disabled_levels:
            commands.append(_enable_disable_cmd(name, "delete", disabled_levels))
        if enabled_levels:
            commands.append(_enable_disable_cmd(name, "add", enabled_levels))
        if not commands:
            return True
    else:
        commands = [_enable_disable_cmd(name, "add")]
    for cmd in commands:
        if _ret_code(cmd):
            return False
    return True


def disable(name, **kwargs):
    """
    Disable the named service to start at boot

    CLI Example:

    .. code-block:: bash

        salt '*' service.disable <service name> <runlevels=single-runlevel>
        salt '*' service.disable <service name> <runlevels=[runlevel1,runlevel2]>
    """
    levels = []
    if "runlevels" in kwargs:
        requested_levels = set(
            kwargs["runlevels"]
            if isinstance(kwargs["runlevels"], list)
            else [kwargs["runlevels"]]
        )
        levels = _disable_delta(name, requested_levels)
        if not levels:
            return True
    cmd = _enable_disable_cmd(name, "delete", levels)
    return not _ret_code(cmd)


def enabled(name, **kwargs):
    """
    Return True if the named service is enabled, false otherwise

    CLI Example:

    .. code-block:: bash

        salt '*' service.enabled <service name> <runlevels=single-runlevel>
        salt '*' service.enabled <service name> <runlevels=[runlevel1,runlevel2]>
    """
    enabled_services = get_enabled()
    if name not in enabled_services:
        return False
    if "runlevels" not in kwargs:
        return True
    requested_levels = set(
        kwargs["runlevels"]
        if isinstance(kwargs["runlevels"], list)
        else [kwargs["runlevels"]]
    )
    return len(requested_levels - set(enabled_services[name])) == 0


def disabled(name):
    """
    Return True if the named service is enabled, false otherwise

    CLI Example:

    .. code-block:: bash

        salt '*' service.disabled <service name> <runlevels=[runlevel]>
    """
    return name in get_disabled()