Generate a csr using the host's private_key.
    Analogous to:

    .. code-block:: bash

        VCert gencsr -cn [CN Value] -o "Beta Organization" -ou "Beta Group" \
            -l "Palo Alto" -st "California" -c US

    CLI Example:

    .. code-block:: bash

        salt-run venafi.gen_csr <minion_id> <dns_name>

def gen_csr(
        minion_id,
        dns_name,
        zone='default',
        country=None,
        state=None,
        loc=None,
        org=None,
        org_unit=None,
        password=None,
    ):
    '''
    Generate a csr using the host's private_key.
    Analogous to:

    .. code-block:: bash

        VCert gencsr -cn [CN Value] -o "Beta Organization" -ou "Beta Group" \
            -l "Palo Alto" -st "California" -c US

    CLI Example:

    .. code-block:: bash

        salt-run venafi.gen_csr <minion_id> <dns_name>
    '''
    tmpdir = tempfile.mkdtemp()
    os.chmod(tmpdir, 0o700)

    bank = 'venafi/domains'
    cache = salt.cache.Cache(__opts__, syspaths.CACHE_DIR)
    data = cache.fetch(bank, dns_name)
    if data is None:
        data = {}
    if 'private_key' not in data:
        data['private_key'] = gen_key(minion_id, dns_name, zone, password)

    tmppriv = '{0}/priv'.format(tmpdir)
    tmpcsr = '{0}/csr'.format(tmpdir)
    with salt.utils.files.fopen(tmppriv, 'w') as if_:
        if_.write(salt.utils.stringutils.to_str(data['private_key']))

    if country is None:
        country = __opts__.get('venafi', {}).get('country')

    if state is None:
        state = __opts__.get('venafi', {}).get('state')

    if loc is None:
        loc = __opts__.get('venafi', {}).get('loc')

    if org is None:
        org = __opts__.get('venafi', {}).get('org')

    if org_unit is None:
        org_unit = __opts__.get('venafi', {}).get('org_unit')

    subject = '/C={0}/ST={1}/L={2}/O={3}/OU={4}/CN={5}'.format(
        country,
        state,
        loc,
        org,
        org_unit,
        dns_name,
    )

    cmd = "openssl req -new -sha256 -key {0} -out {1} -subj '{2}'".format(
        tmppriv,
        tmpcsr,
        subject
    )
    if password is not None:
        cmd += ' -passin pass:{0}'.format(password)
    output = __salt__['salt.cmd']('cmd.run', cmd)

    if 'problems making Certificate Request' in output:
        raise CommandExecutionError(
            'There was a problem generating the CSR. Please ensure that you '
            'have the following variables set either on the command line, or '
            'in the venafi section of your master configuration file: '
            'country, state, loc, org, org_unit'
        )

    with salt.utils.files.fopen(tmpcsr, 'r') as of_:
        csr = salt.utils.stringutils.to_unicode(of_.read())

    data['minion_id'] = minion_id
    data['csr'] = csr
    cache.store(bank, dns_name, data)
    return csr