NePA TesT: Community Network Emulator

#!/usr/bin/python

"""

build.py: build a Mininet VM

Basic idea:

    prepare

    -> create base install image if it's missing

        - download iso if it's missing

        - install from iso onto image

    build

    -> create cow disk for new VM, based on base image

    -> boot it in qemu/kvm with text /serial console

    -> install Mininet

    test

    -> make codecheck

    -> make test

    release

    -> shut down VM

    -> shrink-wrap VM

    -> upload to storage

"""

import os

from os import stat, path

from stat import ST_MODE

from os.path import abspath

from sys import exit, argv

from glob import glob

from subprocess import check_output, call, Popen

from tempfile import mkdtemp

from time import time, strftime, localtime

import argparse

pexpect = None  # For code check - imported dynamically

# boot can be slooooow!!!! need to debug/optimize somehow

TIMEOUT=600

VMImageDir = os.environ[ 'HOME' ] + '/vm-images'

isoURLs = {

    'quetzal32server':

    'http://mirrors.kernel.org/ubuntu-releases/12.10/'

    'ubuntu-12.10-server-i386.iso',

    'quetzal64server':

    'http://mirrors.kernel.org/ubuntu-releases/13.04/'

    'ubuntu-12.04-server-amd64.iso',

    'raring32server':

    'http://mirrors.kernel.org/ubuntu-releases/13.04/'

    'ubuntu-13.04-server-i386.iso',

    'raring64server':

    'http://mirrors.kernel.org/ubuntu-releases/13.04/'

    'ubuntu-13.04-server-amd64.iso',

}

logStartTime = time()

def log( *args, **kwargs ):

    """Simple log function: log( message along with local and elapsed time

       cr: False/0 for no CR"""

    cr = kwargs.get( 'cr', True )

    elapsed = time() - logStartTime

    clocktime = strftime( '%H:%M:%S', localtime() )

    msg = ' '.join( str( arg ) for arg in args )

    output = '%s [ %.3f ] %s' % ( clocktime, elapsed, msg )

    if cr:

        print output

    else:

        print output,

def run( cmd, **kwargs ):

    "Convenient interface to check_output"

    log( '-', cmd )

    cmd = cmd.split()

    return check_output( cmd, **kwargs )

def srun( cmd, **kwargs ):

    "Run + sudo"

    return run( 'sudo ' + cmd, **kwargs )

def depend():

    "Install package dependencies"

    log( '* Installing package dependencies' )

    run( 'sudo apt-get -y update' )

    run( 'sudo apt-get install -y'

         ' kvm cloud-utils genisoimage qemu-kvm qemu-utils'

         ' e2fsprogs '

         ' landscape-client'

         ' python-setuptools' )

    run( 'sudo easy_install pexpect' )

def popen( cmd ):

    "Convenient interface to popen"

    log( cmd )

    cmd = cmd.split()

    return Popen( cmd )

def remove( fname ):

    "rm -f fname"

    return run( 'rm -f %s' % fname )

def findiso( flavor ):

    "Find iso, fetching it if it's not there already"

    url = isoURLs[ flavor ]

    name = path.basename( url )

    iso = path.join( VMImageDir, name )

    if not path.exists( iso ) or ( stat( iso )[ ST_MODE ] & 0777 != 0444 ):

        log( '* Retrieving', url )

        run( 'curl -C - -o %s %s' % ( iso, url ) )

        # Write-protect iso, signaling it is complete

        log( '* Write-protecting iso', iso)

        os.chmod( iso, 0444 )

    log( '* Using iso', iso )

    return iso

def attachNBD( cow, flags='' ):

    """Attempt to attach a COW disk image and return its nbd device

        flags: additional flags for qemu-nbd (e.g. -r for readonly)"""

    # qemu-nbd requires an absolute path

    cow = abspath( cow )

    log( '* Checking for unused /dev/nbdX device ' )

    for i in range ( 0, 63 ):

        nbd = '/dev/nbd%d' % i

        # Check whether someone's already messing with that device

        if call( [ 'pgrep', '-f', nbd ] ) == 0:

            continue

        srun( 'modprobe nbd max-part=64' )

        srun( 'qemu-nbd %s -c %s %s' % ( flags, nbd, cow ) )

        print

        return nbd

    raise Exception( "Error: could not find unused /dev/nbdX device" )

def detachNBD( nbd ):

    "Detatch an nbd device"

    srun( 'qemu-nbd -d ' + nbd )

def extractKernel( image, flavor ):

    "Extract kernel and initrd from base image"

    kernel = path.join( VMImageDir, flavor + '-vmlinuz' )

    initrd = path.join( VMImageDir, flavor + '-initrd' )

    if path.exists( kernel ) and ( stat( image )[ ST_MODE ] & 0777 ) == 0444:

        # If kernel is there, then initrd should also be there

        return kernel, initrd

    log( '* Extracting kernel to', kernel )

    nbd = attachNBD( image, flags='-r' )

    print srun( 'partx ' + nbd )

    # Assume kernel is in partition 1/boot/vmlinuz*generic for now

    part = nbd + 'p1'

    mnt = mkdtemp()

    srun( 'mount -o ro %s %s' % ( part, mnt  ) )

    kernsrc = glob( '%s/boot/vmlinuz*generic' % mnt )[ 0 ]

    initrdsrc = glob( '%s/boot/initrd*generic' % mnt )[ 0 ]

    srun( 'cp %s %s' % ( initrdsrc, initrd ) )

    srun( 'chmod 0444 ' + initrd )

    srun( 'cp %s %s' % ( kernsrc, kernel ) )

    srun( 'chmod 0444 ' + kernel )

    srun( 'umount ' + mnt )

    run( 'rmdir ' + mnt )

    detachNBD( nbd )

    return kernel, initrd

def findBaseImage( flavor, size='8G' ):

    "Return base VM image and kernel, creating them if needed"

    image = path.join( VMImageDir, flavor + '-base.img' )

    if path.exists( image ):

        # Detect race condition with multiple builds

        perms = stat( image )[ ST_MODE ] & 0777

        if perms != 0444:

            raise Exception( 'Error - %s is writable ' % image +

                            '; are multiple builds running?' )

    else:

        # We create VMImageDir here since we are called first

        run( 'mkdir -p %s' % VMImageDir )

        iso = findiso( flavor )

        log( '* Creating image file', image )

        run( 'qemu-img create %s %s' % ( image, size ) )

        installUbuntu( iso, image )

        # Write-protect image, also signaling it is complete

        log( '* Write-protecting image', image)

        os.chmod( image, 0444 )

    kernel, initrd = extractKernel( image, flavor )

    log( '* Using base image', image, 'and kernel', kernel )

    return image, kernel, initrd

# Kickstart and Preseed files for Ubuntu/Debian installer

#

# Comments: this is really clunky and painful. If Ubuntu

# gets their act together and supports kickstart a bit better

# then we can get rid of preseed and even use this as a

# Fedora installer as well.

#

# Another annoying thing about Ubuntu is that it can't just

# install a normal system from the iso - it has to download

# junk from the internet, making this house of cards even

# more precarious.

KickstartText ="""

#Generated by Kickstart Configurator

#platform=x86

#System language

lang en_US

#Language modules to install

langsupport en_US

#System keyboard

keyboard us

#System mouse

mouse

#System timezone

timezone America/Los_Angeles

#Root password

rootpw --disabled

#Initial user

user mininet --fullname "mininet" --password "mininet"

#Use text mode install

text

#Install OS instead of upgrade

install

#Use CDROM installation media

cdrom

#System bootloader configuration

bootloader --location=mbr

#Clear the Master Boot Record

zerombr yes

#Partition clearing information

clearpart --all --initlabel

#Automatic partitioning

autopart

#System authorization infomation

auth  --useshadow  --enablemd5

#Firewall configuration

firewall --disabled

#Do not configure the X Window System

skipx

"""

# Tell the Ubuntu/Debian installer to stop asking stupid questions

PreseedText = """

d-i mirror/country string manual

d-i mirror/http/hostname string mirrors.kernel.org

d-i mirror/http/directory string /ubuntu

d-i mirror/http/proxy string

d-i partman/confirm_write_new_label boolean true

d-i partman/choose_partition select finish

d-i partman/confirm boolean true

d-i partman/confirm_nooverwrite boolean true

d-i user-setup/allow-password-weak boolean true

d-i finish-install/reboot_in_progress note

d-i debian-installer/exit/poweroff boolean true

"""

def makeKickstartFloppy():

    "Create and return kickstart floppy, kickstart, preseed"

    kickstart = 'ks.cfg'

    with open( kickstart, 'w' ) as f:

        f.write( KickstartText )

    preseed = 'ks.preseed'

    with open( preseed, 'w' ) as f:

        f.write( PreseedText )

    # Create floppy and copy files to it

    floppy = 'ksfloppy.img'

    run( 'qemu-img create %s 1440k' % floppy )

    run( 'mkfs -t msdos ' + floppy )

    run( 'mcopy -i %s %s ::/' % ( floppy, kickstart ) )

    run( 'mcopy -i %s %s ::/' % ( floppy, preseed ) )

    return floppy, kickstart, preseed

def kvmFor( filepath ):

    "Guess kvm version for file path"

    name = path.basename( filepath )

    if '64' in name:

        kvm = 'qemu-system-x86_64'

    elif 'i386' in name or '32' in name:

        kvm = 'qemu-system-i386'

    else:

        log( "Error: can't discern CPU for file name", name )

        exit( 1 )

    return kvm

def installUbuntu( iso, image, logfilename='install.log' ):

    "Install Ubuntu from iso onto image"

    kvm = kvmFor( iso )

    floppy, kickstart, preseed = makeKickstartFloppy()

    # Mount iso so we can use its kernel

    mnt = mkdtemp()

    srun( 'mount %s %s' % ( iso, mnt ) )

    srun( 'ls ' + mnt )

    kernel = path.join( mnt, 'install/vmlinuz' )

    initrd = path.join( mnt, 'install/initrd.gz' )

    cmd = [ 'sudo', kvm,

           '-machine', 'accel=kvm',

           '-nographic',

           '-netdev', 'user,id=mnbuild',

           '-device', 'virtio-net,netdev=mnbuild',

           '-m', '1024',

           '-k', 'en-us',

           '-fda', floppy,

           '-drive', 'file=%s,if=virtio' % image,

           '-cdrom', iso,

           '-kernel', kernel,

           '-initrd', initrd,

           '-append',

           ' ks=floppy:/' + kickstart +

           ' preseed/file=floppy://' + preseed +

           ' console=ttyS0' ]

    ubuntuStart = time()

    log( '* INSTALLING UBUNTU FROM', iso, 'ONTO', image )

    log( ' '.join( cmd ) )

    log( '* logging to', abspath( logfilename ) )

    logfile = open( logfilename, 'w' )

    vm = Popen( cmd, stdout=logfile, stderr=logfile )

    log( '* Waiting for installation to complete')

    vm.wait()

    logfile.close()

    elapsed = time() - ubuntuStart

    # Unmount iso and clean up

    srun( 'umount ' + mnt )

    run( 'rmdir ' + mnt )

    log( '* UBUNTU INSTALLATION COMPLETED FOR', image )

    log( '* Ubuntu installation completed in %.2f seconds ' % elapsed )

def boot( cow, kernel, initrd, logfile ):

    """Boot qemu/kvm with a COW disk and local/user data store

       cow: COW disk path

       kernel: kernel path

       logfile: log file for pexpect object

       returns: pexpect object to qemu process"""

    # pexpect might not be installed until after depend() is called

    global pexpect

    import pexpect

    kvm = kvmFor( kernel )

    cmd = [ 'sudo', kvm,

            '-machine accel=kvm',

            '-nographic',

            '-netdev user,id=mnbuild',

            '-device virtio-net,netdev=mnbuild',

            '-m 1024',

            '-k en-us',

            '-kernel', kernel,

            '-initrd', initrd,

            '-drive file=%s,if=virtio' % cow,

            '-append "root=/dev/vda1 init=/sbin/init console=ttyS0" ' ]

    cmd = ' '.join( cmd )

    log( '* BOOTING VM FROM', cow )

    log( cmd )

    vm = pexpect.spawn( cmd, timeout=TIMEOUT, logfile=logfile )

    return vm

def interact( vm ):

    "Interact with vm, which is a pexpect object"

    prompt = '\$ '

    log( '* Waiting for login prompt' )

    vm.expect( 'login: ' )

    log( '* Logging in' )

    vm.sendline( 'mininet' )

    log( '* Waiting for password prompt' )

    vm.expect( 'Password: ' )

    log( '* Sending password' )

    vm.sendline( 'mininet' )

    log( '* Waiting for login...' )

    vm.expect( prompt )

    log( '* Sending hostname command' )

    vm.sendline( 'hostname' )

    log( '* Waiting for output' )

    vm.expect( prompt )

    log( '* Fetching Mininet VM install script' )

    vm.sendline( 'wget '

                 'https://raw.github.com/mininet/mininet/master/util/vm/'

                 'install-mininet-vm.sh' )

    vm.expect( prompt )

    log( '* Running VM install script' )

    vm.sendline( 'bash install-mininet-vm.sh' )

    vm.expect ( 'password for mininet: ' )

    vm.sendline( 'mininet' )

    log( '* Waiting for script to complete... ' )

    # Gigantic timeout for now ;-(

    vm.expect( 'Done preparing Mininet', timeout=3600 )

    log( '* Completed successfully' )

    vm.expect( prompt )

    log( '* Testing Mininet' )

    vm.sendline( 'sudo mn --test pingall' )

    if vm.expect( [ ' 0% dropped', pexpect.TIMEOUT ], timeout=45 ) == 0:

        log( '* Sanity check succeeded' )

    else:

        log( '* Sanity check FAILED' )

    vm.expect( prompt )

    log( '* Making sure cgroups are mounted' )

    vm.sendline( 'sudo service cgroup-lite restart' )

    vm.expect( prompt )

    vm.sendline( 'sudo cgroups-mount' )

    vm.expect( prompt )

    log( '* Running make test' )

    vm.sendline( 'cd ~/mininet; sudo make test' )

    vm.expect( prompt )

    log( '* Shutting down' )

    vm.sendline( 'sync; sudo shutdown -h now' )

    log( '* Waiting for EOF/shutdown' )

    vm.read()

    log( '* Interaction complete' )

def cleanup():

    "Clean up leftover qemu-nbd processes and other junk"

    call( [ 'sudo', 'pkill', '-9', 'qemu-nbd' ] )

def convert( cow, basename ):

    """Convert a qcow2 disk to a vmdk and put it a new directory

       basename: base name for output vmdk file"""

    vmdk = basename + '.vmdk'

    log( '* Converting qcow2 to vmdk' )

    run( 'qemu-img convert -f qcow2 -O vmdk %s %s' % ( cow, vmdk ) )

    return vmdk

def build( flavor='raring32server' ):

    "Build a Mininet VM"

    start = time()

    date = strftime( '%y%m%d-%H-%M-%S', localtime())

    dir = 'mn-%s-%s' % ( flavor, date )

    try:

        os.mkdir( dir )

    except:

        raise Exception( "Failed to create build directory %s" % dir )

    os.chdir( dir )

    log( '* Created working directory', dir )

    image, kernel, initrd = findBaseImage( flavor )

    volume = flavor + '.qcow2'

    run( 'qemu-img create -f qcow2 -b %s %s' % ( image, volume ) )

    log( '* VM image for', flavor, 'created as', volume )

    logfile = open( flavor + '.log', 'w+' )

    log( '* Logging results to', abspath( logfile.name ) )

    vm = boot( volume, kernel, initrd, logfile )

    interact( vm )

    vmdk = convert( volume, basename=flavor )

    log( '* Converted VM image stored as', abspath( vmdk ) )

    end = time()

    elapsed = end - start

    log( '* Results logged to', abspath( logfile.name ) )

    log( '* Completed in %.2f seconds' % elapsed )

    log( '* %s VM build DONE!!!!! :D' % flavor )

    os.chdir( '..' )

def listFlavors():

    "List valid build flavors"

    print '\nvalid build flavors:', ' '.join( isoURLs ), '\n'

def parseArgs():

    "Parse command line arguments and run"

    parser = argparse.ArgumentParser( description='Mininet VM build script' )

    parser.add_argument( '--depend', action='store_true',

                         help='install dependencies for this script' )

    parser.add_argument( '--list', action='store_true',

                         help='list valid build flavors' )

    parser.add_argument( '--clean', action='store_true',

                         help='clean up leftover build junk (e.g. qemu-nbd)' )

    parser.add_argument( 'flavor', nargs='*',

                         help='VM flavor to build (e.g. raring32server)' )

    args = parser.parse_args( argv )

    if args.depend:

        depend()

    if args.list:

        listFlavors()

    if args.clean:

        cleanup()

    flavors = args.flavor[ 1: ]

    for flavor in flavors:

        if flavor not in isoURLs:

            parser.print_help()

            listFlavors()

            break

        # try:

        build( flavor )

        # except Exception as e:

        # log( '* BUILD FAILED with exception: ', e )

        # exit( 1 )

    if not ( args.depend or args.list or args.clean or flavors ):

        parser.print_help()

if __name__ == '__main__':

    parseArgs()