createNodeImage.py

#!/usr/bin/env python
# see https://github.com/oVirt/ovirt-node-ng/blob/master/scripts/node-setup/setup-node-appliance.sh

import os
import requests
import subprocess
import random
import sys


ROOT_PW='123456'

BUILD_URL = ('http://jenkins.ovirt.org/job/'
             'ovirt-node-ng_master_build-artifacts-el7-x86_64/'
             'lastSuccessfulBuild/artifact/exported-artifacts/')

CHECKSUMS_URL = BUILD_URL + 'CHECKSUMS.sha256'
ISO_NAME_XPATH = '//a[1]/@href'
CHUNK_SIZE = 1024*1024
BOOT_ISO_NAME = 'boot.iso'
BOOT_URL = ('http://mirror.centos.org/centos/7/os/x86_64/images/' +
            BOOT_ISO_NAME)
#BOOT_LOCATION = 'http://mirror.centos.org/centos-7/7/os/x86_64/'
# using an iso as location requires root,
# http boot location seems not to work here
BOOT_LOCATION = BOOT_ISO_NAME

VM_MEM = 4096
VM_CPU = 2

KICKSTART="""
lang en_US.UTF-8
keyboard us
timezone --utc Etc/UTC
auth --enableshadow --passalgo=sha512
rootpw {rootpw}
selinux --enforcing
network --bootproto=dhcp
firstboot --reconfig
clearpart --all --initlabel --disklabel=gpt
bootloader --timeout=0
reqpart --add-boot
part pv.01 --size=42000 --grow
volgroup HostVG pv.01
logvol swap --vgname=HostVG --name=swap --fstype=swap --recommended
logvol none --vgname=HostVG --name=HostPool --thinpool --size=40000 --grow
logvol /    --vgname=HostVG --name=root --thin --poolname=HostPool --fsoptions="defaults,discard" --size=6000
logvol /var --vgname=HostVG --name=var --thin --poolname=HostPool --fsoptions="defaults,discard" --size=15000

install
liveimg --url="{img}"
poweroff
%post
set -x
imgbase --debug layout --init
%end
"""


def write_ks_file(file_path, squashfs_img_name):
  with open(file_path,'w') as f:
    f.write(KICKSTART.format(img=get_squashfs_img_url(squashfs_img_name),
      rootpw=ROOT_PW))


def get_squashfs_img_url(squashfs_img_name):
  return BUILD_URL + squashfs_img_name


def get_last_successful_squashfs_img_name():
  response = requests.get(CHECKSUMS_URL)
  assert response.ok
  return filter(lambda l: 'squashfs.img' in l,
                  response.content.splitlines())[0].split(' ')[-1]

def download_boot_iso():
  if not os.path.isfile(BOOT_ISO_NAME):
    download_file(BOOT_URL)


def download_file(url):
    local_filename = url.split('/')[-1]
    r = requests.get(url, stream=True)
    with open(local_filename, 'wb') as f:
        count = 0
        for chunk in r.iter_content(chunk_size=CHUNK_SIZE): 
            if chunk:
                f.write(chunk)
                count += 1
    		print count, '/', int(r.headers['content-length'])/CHUNK_SIZE
    return local_filename


download_boot_iso()

squashfs_img_name = get_last_successful_squashfs_img_name()

vm_name = squashfs_img_name[0:-13]
ks_file = vm_name + '.ks'

write_ks_file(ks_file, squashfs_img_name)

cmd = ['virt-install', 
       '--name {}'.format(vm_name),
       '--boot menu=off', 
       '--memory {}'.format(VM_MEM), 
       '--vcpus {}'.format(VM_CPU),
       '--cpu host',
       '--location {}'.format(BOOT_LOCATION),
       '--extra-args "inst.ks=file:///{} console=ttyS0"'.format(ks_file),
       '--initrd-inject {}'.format(ks_file),
       '--graphics none',
       '--disk cache=unsafe,size=60,path={}.qcow2'.format(vm_name),
       '--os-type=linux',
       '--os-variant=rhel7',
       '--transient',
]

p = subprocess.Popen(' '.join(cmd), shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
for line in iter(p.stdout.readline, ''):
        sys.stdout.write(line)
sys.exit(p.wait())