uncloud-mravi/host/main.py
meow 93dee1c9fc New Features + Refactoring
1. User can now use image name instead of image uuid when creation vm.
   For Example, now user can create an alpine vm using the following
   command
   ```shell
   ucloud-cli vm create --vm-name myvm --cpu 2 --ram '2GB' \
       --os-ssd '10GB' --image images:alpine
   ```
2. Instead of directly running code, code is now placed under a function
   main and is called using the following code
   ```python
   if __name__ == "__main__":
       main()
   ```
3. Multiprocess (Process) is used instead of threading (Thread) to update
   heart beat of host.
4. IP Address of vm is included in vm's status which is retrieved by the
   following command
   ```shell
   ucloud-cli vm status --vm-name myvm
   ```
2019-11-02 20:42:24 +05:00

146 lines
5.5 KiB
Python
Executable file

import argparse
# import threading
import time
import os
import sys
import virtualmachine
import multiprocessing as mp
from ucloud_common.host import HostEntry
from ucloud_common.request import RequestEntry, RequestType
from config import (vm_pool, host_pool, request_pool,
etcd_client, logging, running_vms,
etcd_wrapper_args, etcd_wrapper_kwargs,
REQUEST_PREFIX, HOST_PREFIX,
WITHOUT_CEPH, VM_DIR, HostPool)
from etcd3_wrapper import Etcd3Wrapper
import etcd3
def update_heartbeat(host):
client = Etcd3Wrapper(*etcd_wrapper_args, **etcd_wrapper_kwargs)
host_pool = HostPool(client, HOST_PREFIX)
this_host = host_pool.get(host)
while True:
this_host.update_heartbeat()
host_pool.put(this_host)
time.sleep(10)
def maintenance(host):
# To capture vm running according to running_vms list
# This is to capture successful migration of a VM.
# Suppose, this host is running "vm1" and user initiated
# request to migrate this "vm1" to some other host. On,
# successful migration the destination host would set
# the vm hostname to itself. Thus, we are checking
# whether this host vm is successfully migrated. If yes
# then we shutdown "vm1" on this host.
for running_vm in running_vms:
with vm_pool.get_put(running_vm.key) as vm_entry:
if vm_entry.hostname != host.key and not vm_entry.in_migration:
running_vm.handle.shutdown()
vm_entry.add_log("VM on source host shutdown.")
# To check vm running according to etcd entries
alleged_running_vms = vm_pool.by_status("RUNNING", vm_pool.by_host(host.key))
for vm_entry in alleged_running_vms:
_vm = virtualmachine.get_vm(running_vms, vm_entry.key)
# Whether, the allegedly running vm is in our
# running_vms list or not if it is said to be
# running on this host but it is not then we
# need to shut it down
# This is to capture poweroff/shutdown of a VM
# initiated by user inside VM. OR crash of VM by some
# user running process
if (_vm and not _vm.handle.is_running()) or not _vm:
vm_entry.add_log("""{} is not running but is said to be running.
So, shutting it down and declare it killed""".format(vm_entry.key))
vm_entry.declare_killed()
vm_pool.put(vm_entry)
if _vm:
running_vms.remove(_vm)
def main():
argparser = argparse.ArgumentParser()
argparser.add_argument("hostname", help="Name of this host. e.g /v1/host/1")
args = argparser.parse_args()
assert WITHOUT_CEPH and os.path.isdir(VM_DIR), (
"You have set WITHOUT_CEPH to True. So, the vm directory mentioned"
" in .env file must exists. But, it don't." )
mp.set_start_method('spawn')
heartbeat_updating_process = mp.Process(target=update_heartbeat, args=(args.hostname,))
host_pool = HostPool(etcd_client, HOST_PREFIX)
host = host_pool.get(args.hostname)
assert host, "No such host"
try:
heartbeat_updating_process.start()
except Exception as e:
logging.info("No Need To Go Further. Our heartbeat updating mechanism is not working")
logging.exception(e)
exit(-1)
logging.info("%s Session Started %s", '*' * 5, '*' * 5)
# It is seen that under heavy load, timeout event doesn't come
# in a predictive manner (which is intentional because we give
# higher priority to customer's requests) which delays heart
# beat update which in turn misunderstood by scheduler that the
# host is dead when it is actually alive. So, to ensure that we
# update the heart beat in a predictive manner we start Heart
# beat updating mechanism in separated thread
for events_iterator in [
etcd_client.get_prefix(REQUEST_PREFIX, value_in_json=True),
etcd_client.watch_prefix(REQUEST_PREFIX, timeout=10, value_in_json=True),
]:
for request_event in events_iterator:
request_event = RequestEntry(request_event)
if request_event.type == "TIMEOUT":
logging.info("Timeout Event")
maintenance(host)
continue
# If the event is directed toward me OR I am destination of a InitVMMigration
if (request_event.hostname == host.key or request_event.destination == host.key):
logging.debug("EVENT: %s", request_event)
request_pool.client.client.delete(request_event.key)
vm_entry = vm_pool.get(request_event.uuid)
if vm_entry:
if request_event.type == RequestType.StartVM:
virtualmachine.start(vm_entry)
elif request_event.type == RequestType.StopVM:
virtualmachine.stop(vm_entry)
elif request_event.type == RequestType.DeleteVM:
virtualmachine.delete(vm_entry)
elif request_event.type == RequestType.InitVMMigration:
virtualmachine.init_migration(vm_entry, host.key)
elif request_event.type == RequestType.TransferVM:
virtualmachine.transfer(request_event)
else:
logging.info("VM Entry missing")
logging.info("Running VMs %s", running_vms)
if __name__ == "__main__":
main()