Python脚本实现KVM虚机添加磁盘

import os
import paramiko
from TSDRM import settings
from lxml import etree
from xml.dom.minidom import parse

ip = '192.168.1.61'
username = 'root'
password = '******'
system_tag = 'Linux'
kvm_name = 'Test-1'
disk_file = '/home/images/disk-image/10GB.qcow2'

try:
    linux_file_path = '/etc/libvirt/qemu/{0}.xml'.format(kvm_name)
    file_path = os.path.join(
        os.path.join(
            os.path.join(settings.BASE_DIR, "drm"),
            "upload"
        ),
        "kvmxml"
    )
    local_file_path = file_path + os.sep + "{0}.xml".format(kvm_name)
    ssh = paramiko.Transport((ip, 22))
    ssh.connect(username=username, password=password)
    sftp = paramiko.SFTPClient.from_transport(ssh)
except paramiko.ssh_exception.SSHException as e:
    kvmlog = "连接服务器失败：{0}。".format(e)
else:
    # ①开始下载
    sftp.get(linux_file_path, local_file_path)
    except Exception as e:
    　　kvmlog = "下载linux脚本文件失败：{0}。".format(e)
    else:
        # ②修改本地xml文件：xml文件内容转成dom
        domtree = parse(local_file_path)
        rootnode = domtree.documentElement

        # 找到磁盘父节点
        devices_node = rootnode.getElementsByTagName("devices")[0]

        # 新建disk节点
        """
        <disk type='file' device='disk'>
            <driver name='qemu' type='qcow2'/>
            <source file='/home/images/disk-image/10GB.qcow2'/>
            <target dev='vdb' bus='virtio'/>
            <boot order='2'/>
            <address type='pci'/>
        </disk>
        """
        config = etree.XML(rootnode.toxml())
        kvm_devices = config.xpath("//devices//disk")
        disk_list = []
        for disk in kvm_devices:
            file = disk.xpath('source')
            if file:
                file = disk.xpath('source')[0].attrib['file']
                device = disk.xpath('target')[0].attrib['dev']
                order = disk.xpath('boot')[0].attrib['order']
                disk_list.append({
                    'name': device,
                    'file': file,
                    'order': order
                })
        """
        disk_list:
        [{'order': '1', 'name': 'vda', 'file': '/data/vmdata/Test-4/Test-4.qcow2'},
        {'order': '2', 'name': 'vdb', 'file': '/home/images/disk-image/10GB.qcow2'},
        {'order': '3', 'name': 'vdc', 'file': '/opt/1GB.qcow2'}]

        """
        count = len(disk_list)
        disk_order = count + 1
        disk_dev = ''
        disk_dev_dict = {
            0: 'vda', 1: 'vdb', 2: 'vdc', 3: 'vdd', 4: 'vde', 5: 'vdf', 6: 'vdg',
            7: 'vdh', 8: 'vdi', 9: 'vdj', 10: 'vdk', 11: 'vdl', 12: 'vdm', 13: 'vdn'
        }
        # 动态加载order字段属性和dev字段属性，使之与存在的磁盘数据不同
        for i in disk_list:
            if disk_order == i['order']:
                disk_order += 1
            if disk_dev_dict[count] == i['name']:
                disk_dev = disk_dev_dict[count + 1]
            else:
                disk_dev = disk_dev_dict[count]

        disk_node = domtree.createElement("disk")
        disk_node.setAttribute("type", "file")
        disk_node.setAttribute("device", "disk")

        # 新建driver节点
        driver_node = domtree.createElement("driver")
        driver_node.setAttribute("name", "qemu")
        driver_node.setAttribute("type", "qcow2")

        # 新建source节点
        source_node = domtree.createElement("source")
        source_node.setAttribute("file", disk_file)

        # 新建target节点
        target_node = domtree.createElement("target")
        target_node.setAttribute("dev", disk_dev)
        target_node.setAttribute("bus", "virtio")

        # 新建boot节点
        boot_node = domtree.createElement("boot")
        boot_node.setAttribute("order", str(disk_order))

        # 新建address节点
        address_node = domtree.createElement("address")
        address_node.setAttribute("type", "pci")

        # 磁盘节点添加子节点
        disk_node.appendChild(driver_node)
        disk_node.appendChild(source_node)
        disk_node.appendChild(target_node)
        disk_node.appendChild(boot_node)
        disk_node.appendChild(address_node)

        # 父节点添加子节点：磁盘节点
        devices_node.appendChild(disk_node)

        # 重新覆盖写入本地文件
        try:
            with open(local_file_path, 'w') as f:
                domtree.writexml(f, addindent=' ', encoding='utf-8')
        except Exception as e:
            kvmlog = "修改文件失败：{0}。".format(e)
        else:
            # ③上传到服务器
            try:
                ssh = paramiko.Transport((ip, 22))
                ssh.connect(username=username, password=password)
                sftp = paramiko.SFTPClient.from_transport(ssh)
            except paramiko.ssh_exception.SSHException as e:
                kvmlog = "连接服务器失败：{0}。".format(e)
            else:
                try:
                    # 开始上传
                    sftp.put(local_file_path, linux_file_path)
                except Exception as e:
                    kvmlog = "上传linux脚本文件失败：{0}。".format(e)
                else:
                    log = '上传成功'