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原文地址:http://blog.csdn.net/gtt116/
本文主要分析nova中虛擬機的啓動過程,着重介紹此過程的狀態改變和響應的操作。
代碼整理自 nova/compute/manager.py 代碼的順序有改動,只是爲了方便查看,完整的代碼可以參考:https://github.com/openstack/nova/blob /master/nova/compute/manager.py
虛擬機的創建流程爲3步走:
- 向nova-network申請IP
- 向nova-volumn申請block_device
- 向driver申請創建虛擬機
同時伴隨整個過程,虛擬機的vm_state始終是building,但是task_state將會變化三次:
- networking
- block_device_mapping
- spawing
最後,虛擬機的vm_state變成active.
def run_instance(self):
building proccess:
None
+
networking
| network_api.allocate_for_instance (nova-network)
+
block_device_mapping
| setup_block_device_mapping (nova-volumn)
+
spawing
| driver.spawn (nova-compute.driver)
+
Active
"""
instance = self.db.instance_get_by_uuid(context, instance_uuid)
self._check_instance_not_already_created(context, instance)
image_meta = self._check_image_size(context, instance)
# VM_state = building
# task_state = None
self._instance_update(context, instance['uuid'],
host=self.host, launched_on=self.host,
vm_state=vm_states.BUILDING,
task_state=None)
# VM_state = building
# task_state = networking
self._instance_update(context, instance['uuid'],
vm_state=vm_states.BUILDING,
task_state=task_states.NETWORKING)
network_info = self.network_api.allocate_for_instance(
context, instance, vpn=is_vpn,
requested_networks=requested_networks)
# VM_state = building
# task_statue = block_device_mapping
self._instance_update(context, instance['uuid'],
vm_state=vm_states.BUILDING,
task_state=task_states.BLOCK_DEVICE_MAPPING)
self._setup_block_device_mapping(context, instance)
# VM_state = building
# task_statue = spawing
self._instance_update(context, instance['uuid'],
vm_state=vm_states.BUILDING,
task_state=task_states.SPAWNING)
instance['injected_files'] = injected_files
instance['admin_pass'] = admin_pass
self.driver.spawn(context, instance, image_meta,
self._legacy_nw_info(network_info), block_device_info)
# VM_state = active
# task_statue = None
self._instance_update(context, instance['uuid'],
power_state=current_power_state,
vm_state=vm_states.ACTIVE,
task_state=None,
launched_at=utils.utcnow())
下面上思維圖,希望大家能多多交流!