8. Multiple Virtual Machines Management

When managing multiple virtual machines, waiting around 2 minutes for each VM will be exhausted. So DTS imported parallel threads model into multiple VMs management scenario.

Note

Critical resources and actions which can’t be handled in parallel have been protected by function level lock.

8.1. Command arguments

Multiple VMs module support start VMs or send commands to VMs in parallel with specified arguments format.

Arguments for “start” command:

name	Description	Default value	Must have
name	virtual machine name	N/A	Yes
dut_id	index of DUT	0	No
autodetect_topo	whether detect network topology automatically	False	No
virt_config	virtual machine config location	N/A	Alternative
virt_params	local parameters of virtual machine	N/A	Alternative

Arguments for “cmd” command:

name	Description	Default value	Must have
name	virtual machine name	N/A	Yes
dut_id	index of DUT	0	No
commands	list of commands which will be sent into the vitual machine	N/A	Yes
expects	list of expect output of the commands	N/A	Yes
timeouts	list of timeout value of the commands	N/A	Yes

Note

If there’s nothing expected for the command, still need to define expected string as blank

Multiple module will catagorize and save the result value after all tasks have been done. Later users can retrieve the result by function get_parallel_result.

8.2. Sample Code

vm_task = MultipleVM(max_vm=self.VM_NUM, duts=self.duts)

for dut_id in range(len(self.duts)):
    for vm_idx in range(VM_NUM):
        vm_name = "vm%d" % vm_idx
        args = {'name': vm_name,
                'dut_id': dut_id,
                'autodetect_topo': False,
                'virt_params': {
                    'qemu': [{'path': '/usr/local/bin/qemu-system-x86_64'}],
                    'cpu': [{'model': 'host', 'number': '1', 'cpupin': ''}],
                    'mem': [{'size': '1024', 'hugepage': 'yes'}],
                    'disk': [{'file': '/storage/vm-image/%s.qcow2' % vm_name}],
                    'login': [{'user': 'root', 'password': 'root'}],
                    'device': None}
                }

        vm_task.add_parallel_task(action="start", config=args)

vm_task.do_parallel_task()
print vm_task.get_parallel_result()