#!/usr/bin/python
#
# Copyright (c) 2003 Intel Corporation
# All rights reserved.
#
# Copyright (c) 2004-2006 The Trustees of Princeton University
# All rights reserved.


import string
import re
import os
import time

import utils
import systeminfo
import notify_messages
import BootAPI
import ModelOptions
from Exceptions import BootManagerException

import UpdateNodeConfiguration
import StopRunlevelAgent
import MakeInitrd

def Run(vars, log):
    """
    Load the kernel off of a node and boot to it.
    This step assumes the disks are mounted on SYSIMG_PATH.
    If successful, this function will not return. If it returns, no chain
    booting has occurred.
    
    Expect the following variables:
    SYSIMG_PATH           the path where the system image will be mounted
                          (always starts with TEMP_PATH)
    ROOT_MOUNTED          the node root file system is mounted
    NODE_SESSION             the unique session val set when we requested
                             the current boot state
    PLCONF_DIR               The directory to store PL configuration files in
    
    Sets the following variables:
    ROOT_MOUNTED          the node root file system is mounted
    """

    log.write("\n\nStep: Chain booting node.\n")

    # make sure we have the variables we need
    try:
        SYSIMG_PATH = vars["SYSIMG_PATH"]
        if SYSIMG_PATH == "":
            raise ValueError("SYSIMG_PATH")

        PLCONF_DIR = vars["PLCONF_DIR"]
        if PLCONF_DIR == "":
            raise ValueError("PLCONF_DIR")

        # its ok if this is blank
        NODE_SESSION = vars["NODE_SESSION"]

        NODE_MODEL_OPTIONS = vars["NODE_MODEL_OPTIONS"]

        PARTITIONS = vars["PARTITIONS"]
        if PARTITIONS == None:
            raise ValueError("PARTITIONS")

    except KeyError as var:
        raise BootManagerException("Missing variable in vars: {}\n".format(var))
    except ValueError as var:
        raise BootManagerException("Variable in vars, shouldn't be: {}\n".format(var))

    ROOT_MOUNTED = 0
    if vars.has_key('ROOT_MOUNTED'):
        ROOT_MOUNTED = vars['ROOT_MOUNTED']
    
    if ROOT_MOUNTED == 0:
        log.write("Mounting node partitions\n")

        # simply creating an instance of this class and listing the system
        # block devices will make them show up so vgscan can find the planetlab
        # volume group
        systeminfo.get_block_devices_dict(vars, log)
        
        utils.sysexec("vgscan", log)
        utils.sysexec("vgchange -ay planetlab", log)

        utils.makedirs(SYSIMG_PATH)

        cmd = "mount {} {}".format(PARTITIONS["root"], SYSIMG_PATH)
        utils.sysexec(cmd, log)
        cmd = "mount -t proc none {}/proc".format(SYSIMG_PATH)
        utils.sysexec(cmd, log)
        cmd = "mount {} {}/vservers".format(PARTITIONS["vservers"], SYSIMG_PATH)
        utils.sysexec(cmd, log)

        ROOT_MOUNTED = 1
        vars['ROOT_MOUNTED'] = 1

    utils.display_disks_status(PARTITIONS, "In ChainBootNode", log)

    # write out the session value /etc/planetlab/session
    try:
        session_file_path = "{}/{}/session".format(SYSIMG_PATH, PLCONF_DIR)
        session_file = file(session_file_path, "w")
        session_file.write(str(NODE_SESSION))
        session_file.close()
        session_file = None
        log.write("Updated /etc/planetlab/session\n")
    except IOError as e:
        log.write("Unable to write out /etc/planetlab/session, continuing anyway\n")

    # update configuration files
    log.write("Updating configuration files.\n")
    # avoid using conf_files initscript as we're moving to systemd on some platforms

    if (vars['ONE_PARTITION'] != '1'):
        try:
            cmd = "/usr/bin/env python /usr/share/NodeManager/conf_files.py --noscripts"
            utils.sysexec_chroot(SYSIMG_PATH, cmd, log)
        except IOError as e:
            log.write("conf_files failed with \n {}".format(e))

        # update node packages
        log.write("Running node update.\n")
        if os.path.exists(SYSIMG_PATH + "/usr/bin/NodeUpdate.py"):
            cmd = "/usr/bin/NodeUpdate.py start noreboot"
        else:
            # for backwards compatibility
            cmd = "/usr/local/planetlab/bin/NodeUpdate.py start noreboot"
        utils.sysexec_chroot(SYSIMG_PATH, cmd, log)

    # Re-generate initrd right before kexec call
    # this is not required anymore on recent depls.
    if vars['virt'] == 'vs':
        MakeInitrd.Run(vars, log)

    # the following step should be done by NM
    UpdateNodeConfiguration.Run(vars, log)

    log.write("Updating ssh public host key with PLC.\n")
    ssh_host_key = ""
    try:
        ssh_host_key_file = file("{}/etc/ssh/ssh_host_rsa_key.pub".format(SYSIMG_PATH), "r")
        ssh_host_key = ssh_host_key_file.read().strip()
        ssh_host_key_file.close()
        ssh_host_key_file = None
    except IOError as e:
        pass

    update_vals = {}
    update_vals['ssh_rsa_key'] = ssh_host_key
    BootAPI.call_api_function(vars, "BootUpdateNode", (update_vals,))


    # get the kernel version
    option = ''
    if NODE_MODEL_OPTIONS & ModelOptions.SMP:
        option = 'smp'

    log.write("Copying kernel and initrd for booting.\n")
    if vars['virt'] == 'vs':
        utils.sysexec("cp {}/boot/kernel-boot{} /tmp/kernel".format(SYSIMG_PATH, option), log)
        utils.sysexec("cp {}/boot/initrd-boot{} /tmp/initrd".format(SYSIMG_PATH, option), log)
    else:
        # Use chroot to call rpm, b/c the bootimage&nodeimage rpm-versions may not work together
        try:
            kversion = os.popen("chroot {} rpm -qa kernel | tail -1 | cut -c 8-"\
                                .format(SYSIMG_PATH)).read().rstrip()
            major_version = int(kversion[0]) # Check if the string looks like a kernel version
        except:
            # Try a different method for non-rpm-based distributions
            kversion = os.popen("ls -lrt {}/lib/modules | tail -1 | awk '{{print $9;}}'"\
                                .format(SYSIMG_PATH)).read().rstrip()

        # kernel and initrd come in various locations depending on the distro

        kernel_candidates = []
        kernel_candidates.append("/boot/vmlinux-{}*".format(kversion))
        # on f23 starting dec. 2015 - what a twisted naming scheme
        kernel_candidates.append("/boot/*/{}*/initrd".format(kversion))

        initrd_candidates = []
        # f16/18: expect initramfs image here
        initrd_candidates.append ("/boot/initramfs-{}.img".format(kversion))
        # f20: uses a uid of some kind, e.g. /boot/543f88c129de443baaa65800cf3927ce/<kversion>/initrd
        initrd_candidates.append ("/boot/*/{}/initrd".format(kversion))
        # Ubuntu:
        initrd_candidates.append ("/boot/initrd.img-{}".format(kversion))

        def find_file_in_sysimg (candidates):
            import glob
            for pattern in candidates:
                matches = glob.glob(SYSIMG_PATH+pattern)
                log.write("locating initrd: found {} matches in {}\n".format(len(matches), pattern))
                if matches:
                    return matches[0]

        kernel = find_file_in_sysimg(kernel_candidates)
        if kernel:
            utils.sysexec("cp {} /tmp/kernel".format(kernel), log)
        else:
            raise Exception("Unable to locate kernel - bailing out")


        initrd = find_file_in_sysimg(initrd_candidates)
        if initrd:
            utils.sysexec("cp {} /tmp/initrd".format(initrd), log)
        else:
            raise Exception("Unable to locate initrd - bailing out")

    BootAPI.save(vars)

    log.write("Unmounting disks.\n")
    
    if (vars['ONE_PARTITION'] != '1'):
        utils.sysexec("umount {}/vservers".format(SYSIMG_PATH), log)
    utils.sysexec("umount {}/proc".format(SYSIMG_PATH), log)
    utils.sysexec_noerr("umount {}/dev".format(SYSIMG_PATH), log)
    utils.sysexec_noerr("umount {}/sys".format(SYSIMG_PATH), log)
    utils.sysexec("umount {}".format(SYSIMG_PATH), log)
    utils.sysexec("vgchange -an", log)

    ROOT_MOUNTED = 0
    vars['ROOT_MOUNTED'] = 0

    # Change runlevel to 'boot' prior to kexec.
    StopRunlevelAgent.Run(vars, log)

    log.write("Unloading modules and chain booting to new kernel.\n")

    # further use of log after Upload will only output to screen
    log.Upload("/root/.bash_eternal_history")

    # regardless of whether kexec works or not, we need to stop trying to
    # run anything
    cancel_boot_flag = "/tmp/CANCEL_BOOT"
    utils.sysexec("touch {}".format(cancel_boot_flag), log)

    # on 2.x cds (2.4 kernel) for sure, we need to shutdown everything
    # to get kexec to work correctly. Even on 3.x cds (2.6 kernel),
    # there are a few buggy drivers that don't disable their hardware
    # correctly unless they are first unloaded.
    
    utils.sysexec_noerr("ifconfig eth0 down", log)

    utils.sysexec_noerr("killall dhclient", log)
        
    if vars['virt'] == 'vs':
        utils.sysexec_noerr("umount -a -r -t ext2,ext3", log)
    else:
        utils.sysexec_noerr("umount -a -r -t ext2,ext3,btrfs", log)
    utils.sysexec_noerr("modprobe -r lvm-mod", log)
    
    # modules that should not get unloaded
    # unloading cpqphp causes a kernel panic
    blacklist = [ "floppy", "cpqphp", "i82875p_edac", "mptspi"]
    try:
        modules = file("/tmp/loadedmodules","r")
        
        for line in modules:
            module = string.strip(line)
            if module in blacklist :
                log.write("Skipping unload of kernel module '{}'.\n".format(module))
            elif module != "":
                log.write("Unloading {}\n".format(module))
                utils.sysexec_noerr("modprobe -r {}".format(module), log)
                if "e1000" in module:
                    log.write("Unloading e1000 driver; sleeping 4 seconds...\n")
                    time.sleep(4)

        modules.close()
    except IOError:
        log.write("Couldn't read /tmp/loadedmodules, continuing.\n")

    try:
        modules = file("/proc/modules", "r")

        # Get usage count for USB
        usb_usage = 0
        for line in modules:
            try:
                # Module Size UsageCount UsedBy State LoadAddress
                parts = string.split(line)

                if parts[0] == "usb_storage":
                    usb_usage += int(parts[2])
            except IndexError as e:
                log.write("Couldn't parse /proc/modules, continuing.\n")

        modules.seek(0)

        for line in modules:
            try:
                # Module Size UsageCount UsedBy State LoadAddress
                parts = string.split(line)

                # While we would like to remove all "unused" modules,
                # you can't trust usage count, especially for things
                # like network drivers or RAID array drivers. Just try
                # and unload a few specific modules that we know cause
                # problems during chain boot, such as USB host
                # controller drivers (HCDs) (PL6577).
                # if int(parts[2]) == 0:
                if False and re.search('_hcd$', parts[0]):
                    if usb_usage > 0:
                        log.write("NOT unloading {} since USB may be in use\n".format(parts[0]))
                    else:
                        log.write("Unloading {}\n".format(parts[0]))
                        utils.sysexec_noerr("modprobe -r {}".format(parts[0]), log)
            except IndexError as e:
                log.write("Couldn't parse /proc/modules, continuing.\n")
    except IOError:
        log.write("Couldn't read /proc/modules, continuing.\n")


    kargs = "root={} ramdisk_size=8192".format(PARTITIONS["root"])
    if NODE_MODEL_OPTIONS & ModelOptions.SMP:
        kargs = kargs + " " + "acpi=off"
    try:
        kargsfb = open("/kargs.txt","r")
        moreargs = kargsfb.readline()
        kargsfb.close()
        moreargs = moreargs.strip()
        log.write('Parsed in "{}" kexec args from /kargs.txt\n'.format(moreargs))
        kargs = kargs + " " + moreargs
    except IOError:
        # /kargs.txt does not exist, which is fine. Just kexec with default
        # kargs, which is ramdisk_size=8192
        pass 

    utils.sysexec_noerr('hwclock --systohc --utc ', log)
#    utils.breakpoint("Before kexec");
    try:
        utils.sysexec('kexec --force --initrd=/tmp/initrd --append="{}" /tmp/kernel'.format(kargs), log)
    except BootManagerException as e:
        # if kexec fails, we've shut the machine down to a point where nothing
        # can run usefully anymore (network down, all modules unloaded, file
        # systems unmounted. write out the error, and cancel the boot process

        log.write("\n\n")
        log.write("-------------------------------------------------------\n")
        log.write("kexec failed with the following error. Please report\n")
        log.write("this problem to support@planet-lab.org.\n\n")
        log.write(str(e) + "\n\n")
        log.write("The boot process has been canceled.\n")
        log.write("-------------------------------------------------------\n\n")

    return