#! /usr/bin/python -E
# Authors: Karl MacMillan <kmacmillan@mentalrootkit.com>
#
# Copyright (C) 2007  Red Hat
# see file 'COPYING' for use and warranty information
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation; version 2 or later
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#

import sys

import logging, tempfile, shutil, os, pwd
import traceback
from ConfigParser import SafeConfigParser
import krbV
from optparse import OptionParser

import ipa.config
from ipa import ipautil
from ipaserver import dsinstance, installutils, certs

def usage():
    print "ipa-replica-prepate FQDN (e.g. replica.example.com)"
    sys.exit(1)

def parse_options():
    parser = OptionParser()

    args = ipa.config.init_config(sys.argv)
    options, args = parser.parse_args(args)

    if len(args) != 2:
        parser.error("must provide the fully-qualified name of the replica")

    return options, args

def get_host_name():
    hostname = installutils.get_fqdn()
    try:
        installutils.verify_fqdn(hostname)
    except RuntimeError, e:
        logging.error(str(e))
        sys.exit(1)

    return hostname

def get_realm_name():
    c = krbV.default_context()
    return c.default_realm

def check_ipa_configuration(realm_name):
    config_dir = dsinstance.config_dirname(dsinstance.realm_to_serverid(realm_name))
    if not ipautil.dir_exists(config_dir):
        logging.error("could not find directory instance: %s" % config_dir)
        sys.exit(1)

def export_certdb(realm_name, ds_dir, dir, fname, subject):
    """realm is the kerberos realm for the IPA server.
       ds_dir is the location of the master DS we are creating a replica for.
       dir is the location of the files for the replica we are creating.
       fname is the filename of the PKCS#12 file for this cert (minus the .p12).
       subject is the subject of the certificate we are creating
    """
    ds_ca = certs.CertDB(dsinstance.config_dirname(dsinstance.realm_to_serverid(realm_name)))
    ca = certs.CertDB(dir)
    ca.create_from_cacert(ds_ca.cacert_fname)
    ca.create_server_cert("Server-Cert", subject, ds_ca)

    pkcs12_fname = dir + "/" + fname + ".p12"
    passwd_fname = dir + "/pwdfile.txt"
    fd = open(passwd_fname, "w")
    fd.write("\n")
    fd.close()

    try:
        ca.export_pkcs12(pkcs12_fname, passwd_fname, "Server-Cert")
    except ipautil.CalledProcessError, e:
        print "error exporting CA certificate: " + str(e)
        try:
            os.unlink(pkcs12_fname)
            os.unlink(passwd_fname)
        except:
            pass

    os.unlink(dir + "/cert8.db")
    os.unlink(dir + "/key3.db")
    os.unlink(dir + "/secmod.db")

def get_ds_user(ds_dir):
    uid = os.stat(ds_dir).st_uid
    user = pwd.getpwuid(uid)[0]

    return user

def save_config(dir, realm_name, host_name, ds_user):
    config = SafeConfigParser()
    config.add_section("realm")
    config.set("realm", "realm_name", realm_name)
    config.set("realm", "master_host_name", host_name)
    config.set("realm", "ds_user", ds_user)
    fd = open(dir + "/realm_info", "w")
    config.write(fd)

def copy_files(realm_name, dir):
    config_dir = dsinstance.config_dirname(dsinstance.realm_to_serverid(realm_name))
    try:
        shutil.copy("/var/kerberos/krb5kdc/ldappwd", dir + "/ldappwd") 
        shutil.copy("/usr/share/ipa/html/preferences.html", dir + "/preferences.html")
        shutil.copy("/usr/share/ipa/html/configure.jar", dir + "/configure.jar")
        shutil.copy(config_dir + "/cacert.asc", dir + "/ca.crt")
    except Exception, e:
        print "error copying files: " + str(e)
        sys.exit(1)

def main():
    options, args = parse_options()

    replica_fqdn = args[1]

    realm_name = get_realm_name()
    check_ipa_configuration(realm_name)

    host_name = get_host_name()
    ds_dir = dsinstance.config_dirname(realm_name)
    ds_user = get_ds_user(ds_dir)

    print "Preparing replica for %s from %s" % (replica_fqdn, host_name)

    top_dir = tempfile.mkdtemp("ipa")
    dir = top_dir + "/realm_info"
    os.mkdir(dir, 0700)

    print "Creating SSL certificate for the Directory Server"
    export_certdb(realm_name, ds_dir, dir, "dscert", "cn=%s,ou=Fedora Directory Server" % replica_fqdn)
    print "Creating SSL certificate for the Web Server"
    export_certdb(realm_name, ds_dir, dir, "httpcert", "cn=%s,ou=Apache Web Server" % replica_fqdn)
    print "Copying additional files"
    copy_files(realm_name, dir)
    print "Finalizing configuration"
    save_config(dir, realm_name, host_name, ds_user)

    print "Packaging the replica into %s" % "replica-info-" + realm_name
    ipautil.run(["/bin/tar", "cfz", "replica-info-" + realm_name, "-C", top_dir, "realm_info"])

    shutil.rmtree(dir)

try:
    if not os.geteuid()==0:
        sys.exit("\nYou must be root to run this script.\n")
    if not ipautil.file_exists("/usr/share/ipa/serial"):
        sys.exist("The replica must be created on the primary IPA server.")

    main()
except Exception, e:
    print "preparation of replica failed: %s" % str(e)
    message = str(e)
    for str in traceback.format_tb(sys.exc_info()[2]):
        message = message + "\n" + str
    logging.debug(message)
    print message
    sys.exit(1)