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|
#!/usr/bin/env python3
import os
import shlex
import shutil
import signal
import subprocess
import tempfile
import time
CLOUD_INIT_META_TEMPLATE = """\
# Amazon EC2 style metadata
local-hostname: {hostname}
"""
CLOUD_INIT_USER_TEMPLATE = """\
#cloud-config
ssh_authorized_keys:
- {pubkey}
"""
class Qemu:
def __init__(self, name, base_image, disk_size, pubkey):
self._name = name
self._dirname = tempfile.mkdtemp()
self._image = self._copy_image(base_image, disk_size)
self._pubkey = pubkey
self._memory = 512
self._vcpus = 1
self._username = None
self._port = None
self._pid = None
def _join(self, *names):
return os.path.join(self._dirname, *names)
def set_disk_size(self, size):
self._disk_size = str(size * 1024 * 1024)
def set_memory(self, memory):
self._memory = memory
def set_vcpus(self, vcpus):
self._vcpus = vcpus
def set_username(self, username):
self._username = username
def _copy_image(self, base_image, size):
image = self._join("qemu.img")
shutil.copy(base_image, image)
if size is not None:
subprocess.check_call(["qemu-img", "resize", "-q", image, str(size)])
return image
def _cloud_init_iso(self):
iso = self._join("cloud-init.iso")
config = self._join("cloud-init")
os.mkdir(config)
meta = os.path.join(config, "meta-data")
write_file(meta, CLOUD_INIT_META_TEMPLATE.format(hostname=self._name))
user = os.path.join(config, "user-data")
write_file(user, CLOUD_INIT_USER_TEMPLATE.format(pubkey=self._pubkey))
if os.path.exists(iso):
os.remove(iso)
subprocess.check_call(
[
"genisoimage",
"-quiet",
"-joliet",
"-rock",
"-output",
iso,
"-volid",
"cidata",
config,
]
)
return iso
def start_qemu(self):
iso = self._cloud_init_iso()
self._port = 2222 # FIXME
pid_file = self._join("qemu.pid")
out_file = self._join("qemu.out")
err_file = self._join("qemu.err")
argv = [
"/usr/sbin/daemonize",
"-c",
self._dirname,
"-p",
pid_file,
"-e",
err_file,
"-o",
out_file,
"/usr/bin/qemu-system-x86_64",
"-name",
self._name,
"-m",
str(self._memory),
"-cpu",
"host",
"-smp",
f"cpus={self._vcpus}",
"-drive",
f"file={self._image},format=qcow2,cache=none,if=virtio",
"-drive",
f"file={iso},if=ide,media=cdrom",
"-device",
"virtio-net,netdev=user.0",
"-netdev",
f"user,id=user.0,hostfwd=tcp::{self._port}-:22",
"-nographic",
"-enable-kvm",
]
subprocess.check_call(argv, stdout=None, stderr=None)
self._pid = int(wait_for(lambda: got_pid(pid_file), 1))
def stop_qemu(self):
if self._pid is not None:
os.kill(self._pid, signal.SIGTERM)
def wait_for_ssh(self):
return wait_for(lambda: self.ssh(["hostname"]), 60)
def ssh(self, argv):
assert self._username is not None
known = self._join("known.hosts")
p = subprocess.Popen(
[
"ssh",
"-p",
str(self._port),
"-l",
self._username,
f"-ouserknownhostsfile={known}",
f"-ostricthostkeychecking=accept-new",
"localhost",
"--",
]
+ [shlex.quote(x) for x in argv],
stdout=subprocess.PIPE,
stderr=subprocess.DEVNULL,
)
output, _ = p.communicate()
if output:
return output, p.returncode
time.sleep(5)
def read_file(filename):
with open(filename, "r") as f:
return f.read()
def write_file(filename, content):
with open(filename, "w") as f:
f.write(content)
def wait_for(func, timeout):
start = time.time()
while time.time() < start + timeout:
val = func()
if val is not None:
return val
time.sleep(0.1)
def got_pid(pid_file):
if os.path.exists(pid_file):
pid = read_file(pid_file)
if pid:
return pid.strip()
vmname = "scap-dev"
pubkey = read_file("/home/liw/.ssh/liw-openpgp.pub")
base_image = "/home/liw/tmp/debian-10-openstack-amd64.qcow2"
username = "debian"
memory = 1024
vcpus = 1
qemu = Qemu(vmname, base_image, 100 * 1024 ** 3, pubkey)
qemu.set_memory(memory)
qemu.set_vcpus(vcpus)
qemu.set_username(username)
print("starting qemu")
qemu.start_qemu()
print("waiting for ssh")
if qemu.wait_for_ssh():
print("got ssh")
out, exit = qemu.ssh(["id"])
print(out.decode("UTF8"))
out, exit = qemu.ssh(["find", "-ls"])
print(out.decode("UTF8"))
qemu.stop_qemu()
else:
print("did not get ssh, boo")
|
