diff options
Diffstat (limited to 'subplot/qemumgr.py')
-rwxr-xr-x | subplot/qemumgr.py | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/subplot/qemumgr.py b/subplot/qemumgr.py new file mode 100755 index 0000000..c4fd385 --- /dev/null +++ b/subplot/qemumgr.py @@ -0,0 +1,216 @@ +#!/usr/bin/env python3 + + +import logging +import os +import random +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 QemuSystem: + def __init__(self, name, base_image, disk_size, pubkey): + self._name = name + self._dirname = "." + 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 + + fd, self._knownhosts = tempfile.mkstemp() + os.close(fd) + + 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 get_port(self): + return self._port + + def _copy_image(self, base_image, size): + image = self._join("qemu.img") + logging.debug(f"QemuSystem: actual disk image: {image}") + 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(self): + iso = self._cloud_init_iso() + + self._port = random.randint(2000, 30000) + pid_file = self._join("qemu.pid") + out_file = self._join("qemu.out") + err_file = self._join("qemu.err") + + MiB = 1024 ** 2 + memory = int(self._memory / MiB) + + argv = [ + "/usr/bin/daemonize", + "-c", + self._dirname, + "-p", + pid_file, + "-e", + err_file, + "-o", + out_file, + "/usr/bin/qemu-system-x86_64", + "-name", + self._name, + "-m", + str(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)) + + logging.debug("started qemu-system") + logging.debug(f" argv: {argv}") + logging.debug(f" pid: {self._pid}") + + def stop(self): + if self._pid is not None: + logging.debug(f"killing qemu-system process {self._pid}") + os.kill(self._pid, signal.SIGTERM) + + def wait_for_ssh(self): + def ssh_ok(): + output, exit = self.ssh(["true"]) + logging.debug(f"tried ssh, exit={exit}") + if exit == 0: + return True + return None + + return wait_for(ssh_ok, 300, sleep=5) + + def ssh(self, argv): + assert self._username is not None + + srcdir = globals()["srcdir"] + + ssh_opts = [ + "-i", + os.path.join(srcdir, "ssh", "id"), + "-p", + str(self._port), + "-l", + self._username, + f"-ouserknownhostsfile={self._knownhosts}", + "-ostricthostkeychecking=accept-new", + "-opasswordauthentication=no", + ] + + real_argv = ( + ["ssh"] + ssh_opts + ["localhost", "--"] + [shlex.quote(x) for x in argv] + ) + + logging.debug(f"running on VM: {real_argv}") + p = subprocess.Popen( + real_argv, stdout=subprocess.PIPE, stderr=subprocess.STDOUT + ) + output, _ = p.communicate() + logging.debug(f"exit code: {p.returncode}") + logging.debug(f"output: {output}") + return output, p.returncode + + +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, sleep=0.1): + start = time.time() + while time.time() < start + timeout: + val = func() + if val is not None: + return val + time.sleep(sleep) + + +def got_pid(pid_file): + if os.path.exists(pid_file): + pid = read_file(pid_file) + if pid: + return pid.strip() |