wip python port of VM management script
This commit is contained in:
parent
5b3e79c671
commit
eef84fb2b9
|
|
@ -0,0 +1,255 @@
|
|||
#!/usr/bin/env python3
|
||||
|
||||
import os
|
||||
import re
|
||||
import shlex
|
||||
import socket
|
||||
import subprocess
|
||||
import sys
|
||||
import tomllib
|
||||
|
||||
## BINARY PATHS
|
||||
|
||||
IP = '/usr/bin/ip'
|
||||
MODPROBE = '/usr/bin/modprobe'
|
||||
MOUNT = '/usr/bin/mount'
|
||||
QEMU = '/usr/bin/qemu-system-x86_64'
|
||||
QEMU_NBD = '/usr/bin/qemu-nbd'
|
||||
SETPRIV = '/usr/bin/setpriv'
|
||||
SOCAT = '/usr/bin/socat'
|
||||
UMOUNT = '/usr/bin/umount'
|
||||
VIRTIOFSD = '/usr/lib/virtiofsd'
|
||||
|
||||
## CONSTANTS
|
||||
|
||||
CFG_BASE = '/srv/vm'
|
||||
RUN_BASE = '/run/vm'
|
||||
|
||||
MAC_FMT = '52:54:00:00:00:{:02x}'
|
||||
IP4_FMT = '10.238.2.{:03d}'
|
||||
IP6_FMT = '2a00:5881:4008:46ff::2{:02x}'
|
||||
|
||||
HOST_IP4 = '10.238.1.1'
|
||||
HOST_IP6 = '2a00:5881:4008:46ff::101'
|
||||
QEMU_USER = 'qemu'
|
||||
QEMU_GROUP = 'qemu'
|
||||
|
||||
def exit_fail(msg):
|
||||
print(f'[error] {msg}', file=sys.stderr)
|
||||
sys.exit(1)
|
||||
|
||||
def exit_ok(msg):
|
||||
print(f'[info] {msg}', file=sys.stderr)
|
||||
sys.exit(0)
|
||||
|
||||
class VM:
|
||||
def __init__(self, vm_name):
|
||||
if not re.match(r'[a-zA-Z]+[0-9]*$', vm_name):
|
||||
raise ValueError(f'bad VM name: {vm_name}')
|
||||
|
||||
self.name = vm_name
|
||||
|
||||
self.cfg_dir = os.path.join(CFG_BASE, vm_name)
|
||||
self.run_dir = os.path.join(RUN_BASE, vm_name)
|
||||
|
||||
self.ifname = f'vm-{vm_name}'
|
||||
self.cfg_path = os.path.join(self.cfg_dir, 'config.toml')
|
||||
self.disk_path = os.path.join(self.cfg_dir, 'disk.qcow2')
|
||||
self.console_path = os.path.join(self.run_dir, 'console.sock')
|
||||
self.control_path = os.path.join(self.run_dir, 'monitor.sock')
|
||||
|
||||
def is_running(self):
|
||||
return os.path.exists(self.control_path)
|
||||
|
||||
def check_running(self):
|
||||
"""Check if VM is running, if not fail gracefully."""
|
||||
|
||||
if not self.is_running():
|
||||
exit_fail(f'control socket not found, is VM {self.name} running?')
|
||||
|
||||
def send_command(self, cmd):
|
||||
"""Send QEMU monitor command to VM.
|
||||
|
||||
See https://www.qemu.org/docs/master/system/monitor.html."""
|
||||
|
||||
self.check_running()
|
||||
|
||||
ctrl = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
|
||||
try:
|
||||
ctrl.connect(self.control_path)
|
||||
except Exception as err:
|
||||
exit_fail(f'cannot connect to control socket: {err!s}')
|
||||
|
||||
data = cmd + '\n'
|
||||
ctrl.sendall(data.encode('ascii'))
|
||||
|
||||
ctrl.close()
|
||||
|
||||
def do_mount(self):
|
||||
if self.is_running():
|
||||
exit_fail('cannot mount rootfs while VM is running')
|
||||
if not os.getuid() == 0:
|
||||
exit_fail('must be root (uid=0) to mount VM rootfs')
|
||||
if not os.path.exists(self.disk_path):
|
||||
exit_fail(f'VM rootfs image does not exist: {self.disk_path}')
|
||||
|
||||
mnt_path = os.path.join('/tmp', self.name)
|
||||
if os.path.ismount(mnt_path):
|
||||
exit_fail('VM rootfs is already mounted')
|
||||
if os.path.exists(mnt_path):
|
||||
exit_fail(f'stale mountpoint already exists, please clean-up: {mnt_path}')
|
||||
|
||||
subprocess.run([MODPROBE, 'nbd'])
|
||||
subprocess.run([QEMU_NBD, '--connect=/dev/nbd0', self.disk_path])
|
||||
|
||||
os.mkdir(mnt_path)
|
||||
subprocess.run([MOUNT, '/dev/nbd0p1', mnt_path])
|
||||
subprocess.run([MOUNT, '-t', 'proc', os.path.join(mnt_path, 'proc')])
|
||||
subprocess.run([MOUNT, '-t', 'sysfs', os.path.join(mnt_path, 'sys')])
|
||||
subprocess.run([MOUNT, '--rbind', '/dev', os.path.join(mnt_path, 'dev')])
|
||||
subprocess.run([MOUNT, '--make-rslave', mnt_path])
|
||||
|
||||
exit_ok(f'mounted VM rootfs at {mnt_path}')
|
||||
|
||||
def do_umount(self):
|
||||
if self.is_running():
|
||||
exit_fail('cannot unmount rootfs while VM is running')
|
||||
if not os.getuid() == 0:
|
||||
exit_fail('must be root (uid=0) to unmount VM rootfs')
|
||||
|
||||
mnt_path = os.path.join('/tmp', self.name)
|
||||
if not os.path.exists(mnt_path):
|
||||
exit_fail('mountpoint not found, is VM rootfs is mounted?')
|
||||
if not os.path.ismount(mnt_path):
|
||||
exit_fail(f'stale mountpoint exists, please clean-up: {mnt_path}')
|
||||
|
||||
subprocess.run([UMOUNT, '--recursive', mnt_path])
|
||||
os.rmdir(mnt_path)
|
||||
subprocess.run([QEMU_NBD, '--disconnect', '/dev/nbd0'])
|
||||
subprocess.run([RMMOD, 'nbd'])
|
||||
|
||||
exit_ok('unmounted VM rootfs\n')
|
||||
|
||||
def do_monitor(self):
|
||||
self.check_running()
|
||||
print(f'[info] connecting to QEMU monitor of VM: {self.name}')
|
||||
print('[info] press ctrl-c to exit')
|
||||
os.execv(SOCAT, ['socat', 'readline', f'unix-connect:{self.control_path}'])
|
||||
|
||||
def do_console(self):
|
||||
self.check_running()
|
||||
print(f'[info] connecting to console of VM: {self.name}')
|
||||
print('[info] press ctrl-o to exit')
|
||||
os.execv(SOCAT, ['socat', '-,escape=0x0f,raw,echo=0', f'unix-connect:{self.console_path}'])
|
||||
|
||||
def do_stop(self):
|
||||
self.send_command('system_poweroff')
|
||||
subprocess.run([IP, 'link', 'del', self.ifname])
|
||||
|
||||
def do_reload(self):
|
||||
self.send_command('system_reset')
|
||||
|
||||
def do_start(self):
|
||||
if self.is_running():
|
||||
exit_fail('VM is already running')
|
||||
|
||||
if not os.path.exists(self.cfg_path):
|
||||
exit_fail(f'VM config file does not exist: {self.cfg_path}')
|
||||
if not os.path.exists(self.disk_path):
|
||||
exit_fail(f'VM rootfs image does not exist: {self.disk_path}')
|
||||
|
||||
print('[info] loading config', file=sys.stderr)
|
||||
|
||||
try:
|
||||
with open(self.cfg_path, 'r') as fd:
|
||||
cfg = tomllib.load(fd)
|
||||
except Exception as err:
|
||||
exit_fail(f'could not load VM config file: {err!s}')
|
||||
|
||||
for k in ('id', 'vcpu_number', 'memory_size'):
|
||||
if k not in cfg:
|
||||
exit_fail(f'configuration: "{k}" is required')
|
||||
|
||||
vm_id = cfg['id']
|
||||
vm_mem = cfg['memory_size']
|
||||
vm_cpu = cfg['vcpu_number']
|
||||
|
||||
if not isinstance(vm_id, int):
|
||||
exit_fail('configuration: "id" must be an integer')
|
||||
if not isinstance(vm_cpu, int):
|
||||
exit_fail('configuration: "vcpu_number" must be an integer')
|
||||
|
||||
shares = cfg.get('shares', [])
|
||||
if not isinstance(shares, list):
|
||||
exit_fail('configuration: "shares" must be an array')
|
||||
for s in shares:
|
||||
for k in ('tag', 'host_path'):
|
||||
if k not in s:
|
||||
exit_fail(f'configuration: "[[shares]]" must contain key "{k}"')
|
||||
if not re.match(r'[a-zA-Z]+[0-9]*', s['tag']):
|
||||
exit_fail('configuration: "[[shares]].tag" is not valid')
|
||||
|
||||
extra_args = cfg.get('qemu_extra_args', '')
|
||||
if not isinstance(extra_args, str):
|
||||
exit_fail('configuration: "qemu_extra_args" must be a string')
|
||||
try:
|
||||
extra_args = shlex.split(extra_args)
|
||||
except Exception as err:
|
||||
exit_fail(f'error parsing "qemu_extra_args": {err!s}')
|
||||
|
||||
vm_mac = MAC_FMT.format(vm_id)
|
||||
vm_ip4 = IP4_FMT.format(vm_id)
|
||||
vm_ip6 = IP6_FMT.format(vm_id)
|
||||
|
||||
print('[info] starting network', file=sys.stderr)
|
||||
|
||||
subprocess.run([IP, 'tuntap', 'add', 'dev', self.ifname, 'mode', 'tag', 'group', QEMU_GROUP])
|
||||
subprocess.run([IP, 'link', 'set', 'dev', self.ifname, 'up'])
|
||||
subprocess.run([IP, 'address', 'add', HOST_IP4, 'dev', self.ifname])
|
||||
subprocess.run([IP, 'address', 'add', HOST_IP6, 'dev', self.ifname])
|
||||
subprocess.run([IP, 'route', 'add', vm_ip4, 'dev', self.ifname])
|
||||
subprocess.run([IP, 'route', 'add', vm_ip6, 'dev', self.ifname])
|
||||
|
||||
print('[info] starting virtiofsd', file=sys.stderr)
|
||||
|
||||
for s in shares:
|
||||
tag = s['tag']
|
||||
path = s['host_path']
|
||||
sock_path = os.path.join(self.run_dir, f'vhost-fs-{tag}.sock')
|
||||
|
||||
# spawn virtiofs server
|
||||
subprocess.Popen([
|
||||
VIRTIOFSD,
|
||||
'--socket-path', sock_path,
|
||||
'--socket-group', QEMU_GROUP,
|
||||
'--shared-dir', path,
|
||||
'--cache', 'always'])
|
||||
|
||||
# add extra qemu config
|
||||
extra_args.extend([
|
||||
'-chardev', f'socket,id=vhost-{tag},path={sock_path}',
|
||||
'-device', f'vhost-user-fs-pci,queue-size=1024,chardev=vhost-{tag},tag={tag}'])
|
||||
|
||||
print('[info] starting qemu', file=sys.stderr)
|
||||
|
||||
mem_opt = ',share=on' if shares else ''
|
||||
|
||||
os.execv(SETPRIV,
|
||||
[SETPRIV,
|
||||
'--reuid', QEMU_USER, '--regid', QEMU_GROUP, '--init-groups',
|
||||
'--inh-caps', '-all', '--reset-env',
|
||||
QEMU,
|
||||
'-nodefaults', '-no-user-config', '-nographics', '-enable-kvm', '-sandbox', 'on',
|
||||
'-machine', 'pc', '-cpu', 'host', '-smp', vm_cpu, '-m', vm_mem,
|
||||
'-monitor', f'unix:{self.control_path},server=on,wait=off',
|
||||
'-serial', f'unix:{self.console_path},server=on,wait=off',
|
||||
# memory
|
||||
'-object', f'memory-backend-file,id=mem0,size={mem},mem-path=/dev/hugepages/qemu{mem_opt}',
|
||||
'-numa', 'node,memdev=mem0',
|
||||
# disk
|
||||
'-drive', f'file={self.disk_path},format=qcow2,id=disk0,if=none',
|
||||
'-device' 'virtio-blk-pci,drive=disk0',
|
||||
# network
|
||||
'-netdev', f'tap,id=net0,ifname={self.ifname},script=no,downscript=no,vhost=on',
|
||||
'-device', f'virtio-net-pci,mac={vm_mac},netdev=net0',
|
||||
*extra_args])
|
||||
Loading…
Reference in New Issue