debconfmod.py

'''
Support for Debconf
'''

# Import python libs
import logging
import os
import re

# Import salt libs
import salt.utils

log = logging.getLogger(__name__)

__func_alias__ = {
    'set_': 'set'
}


def __virtual__():
    '''
    Confirm this module is on a Debian based system and that debconf-utils
    is installed.
    '''
    if __grains__['os_family'] != 'Debian':
        return False

    if salt.utils.which('debconf-get-selections') is None:
        log.info('Package debconf-utils is not installed.')
        return False

    return 'debconf'


def _unpack_lines(out):
    '''
    Unpack the debconf lines
    '''
    rexp = ('(?ms)'
            '^(?P<package>[^#]\\S+)[\t ]+'
            '(?P<question>\\S+)[\t ]+'
            '(?P<type>\\S+)[\t ]+'
            '(?P<value>[^\n]*)$')
    lines = re.findall(rexp, out)
    return lines


def get_selections(fetchempty=True):
    '''
    Answers to debconf questions for all packages in the following format::

        {'package': [['question', 'type', 'value'], ...]}

    CLI Example:

    .. code-block:: bash

        salt '*' debconf.get_selections
    '''
    selections = {}
    cmd = 'debconf-get-selections'

    out = __salt__['cmd.run_stdout'](cmd)

    lines = _unpack_lines(out)

    for line in lines:
        package, question, type_, value = line
        if fetchempty or value:
            (selections
                .setdefault(package, [])
                .append([question, type_, value]))

    return selections


def show(name):
    '''
    Answers to debconf questions for a package in the following format::

        [['question', 'type', 'value'], ...]

    If debconf doesn't know about a package, we return None.

    CLI Example:

    .. code-block:: bash

        salt '*' debconf.show <package name>
    '''
    selections = get_selections()

    result = selections.get(name)
    return result


def _set_file(path):
    '''
    Execute the set selections command for debconf
    '''

    path = _get_template_texts(source_list = [ path ], 
                               template='jinja', 
                               defaults = None,
                               context = None, 
                               env = 'base', **kwargs)
                               
    cmd = 'debconf-set-selections {0}'.format(path)

    __salt__['cmd.run_stdout'](cmd)


def set_(package, question, type, value, *extra):
    '''
    Set answers to debconf questions for a package.

    CLI Example:

    .. code-block:: bash

        salt '*' debconf.set <package> <question> <type> <value> [<value> ...]
    '''

    if extra:
        value = ' '.join((value,) + tuple(extra))

    fd_, fname = salt.utils.mkstemp(prefix="salt-", close_fd=False)

    line = "{0} {1} {2} {3}".format(package, question, type, value)
    os.write(fd_, line)
    os.close(fd_)

    _set_file(fname)

    os.unlink(fname)

    return True


def set_file(path, **kwargs):
    '''
    Set answers to debconf questions from a file.

    CLI Example:

    .. code-block:: bash

        salt '*' debconf.set_file salt://pathto/pkg.selections
    '''
    path = __salt__['cp.cache_file'](path, kwargs.get('__env__', 'base'))
    if path:
        _set_file(path)
        return True

    return False


def _get_template_texts(source_list = [], template='jinja', defaults = None,
                        context = None, env = 'base', **kwargs):
    '''
    Iterate a list of sources and process them as templates.
    Returns a list of 'chunks' containing the rendered templates.
    '''

    ret = {'name': '_get_template_texts', 'changes': {},
           'result': True, 'comment': '', 'data': []}

    if not source_list:
        return _error(ret,
                      '_get_template_texts called with empty source_list')
  
    txtl = []
  
    for (source, source_hash) in source_list:

        # FIX TODO: Remove this when
        # http://github.com/saltstack/salt/issues/7290
        # is closed. Until then, that bug is why its broke :-P

        tmpctx = defaults if defaults else {}
        if context:
            tmpctx.update(context)
        rndrd_templ_fn = __salt__['cp.get_template'](source,'',
                                  template=template, env=env,
                                  context = tmpctx, **kwargs )
        msg = 'cp.get_template returned {0} (Called with: {1})'
        log.debug(msg.format(rndrd_templ_fn,source))
        if rndrd_templ_fn:
            tmplines = None
            with salt.utils.fopen(rndrd_templ_fn, 'rb') as fp_:
                tmplines = fp_.readlines()
            if not tmplines:
                msg = 'Failed to read rendered template file {0} ({1})'
                log.debug( msg.format(rndrd_templ_fn,source))
                ret['name'] = source
                return _error(ret, msg.format( rndrd_templ_fn,source) )
            txtl.append( ''.join(tmplines))
        else:
            msg = 'Failed to load template file {0}'.format(source)
            log.debug(msg)
            ret['name'] = source
            return _error(ret, msg )

    ret['data'] = txtl
    return ret