首先，我想为我糟糕的英语道歉。
我通常会在几个小时、几天甚至几周的研究后找到答案，但今天，我感到很失落，希望得到一些帮助。
目标：
我的目标是与 Netplan 设置桥接接口。该桥接口将通过 DHCP 向我的来宾操作系统 (KVM) 提供 IP 地址。
问题：
我的来宾操作系统无法通过桥接口建立连接。问题可能来自 Netplan 的配置或用于安装来宾操作系统的参数。
语境：
我的服务器运行 Ubuntu Bionic 18.04 LTS，它是由外部提供商托管的云服务器。我想要安装的客户操作系统也是 Ubuntu Bionic 18.04 LTS 发行版。我的服务器支持硬件虚拟化，能够运行硬件加速的KVM虚拟机。
主机操作系统的初始网络状态：
的输出ifconfig -a是：
ens3: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 10.52.16.185 netmask 255.255.255.0 broadcast 10.52.16.255
inet6 fe80::f816:3eff:fe82:c5fe prefixlen 64 scopeid 0x20<link>
inet6 2001:1600:4:8:f816:3eff:fe82:c5fe prefixlen 64 scopeid 0x0<global>
ether fa:16:3e:82:c5:fe txqueuelen 1000 (Ethernet)
RX packets 255880 bytes 22882442 (22.8 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 582 bytes 49337 (49.3 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 138 bytes 10546 (10.5 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 138 bytes 10546 (10.5 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
的输出ip route是：
default via 10.52.16.1 dev ens3 proto dhcp metric 100
10.52.11.0/24 dev ens3 proto dhcp scope link metric 100
10.52.16.0/24 dev ens3 proto kernel scope link src 10.52.16.185
10.52.20.0/24 dev ens3 proto dhcp scope link metric 100
10.52.24.0/24 dev ens3 proto dhcp scope link metric 100
169.254.169.254 via 10.52.16.1 dev ens3 proto dhcp metric 100
的输出lspci是：
00:00.0 Host bridge: Intel Corporation 440FX - 82441FX PMC [Natoma] (rev 02)
00:01.0 ISA bridge: Intel Corporation 82371SB PIIX3 ISA [Natoma/Triton II]
00:01.1 IDE interface: Intel Corporation 82371SB PIIX3 IDE [Natoma/Triton II]
00:01.2 USB controller: Intel Corporation 82371SB PIIX3 USB [Natoma/Triton II] (rev 01)
00:01.3 Bridge: Intel Corporation 82371AB/EB/MB PIIX4 ACPI (rev 03)
00:02.0 VGA compatible controller: Cirrus Logic GD 5446
00:03.0 Ethernet controller: Red Hat, Inc Virtio network device
00:04.0 SCSI storage controller: Red Hat, Inc Virtio block device
00:05.0 SCSI storage controller: Red Hat, Inc Virtio block device
00:06.0 Unclassified device [00ff]: Red Hat, Inc Virtio memory balloon
$ networkctl -a 状态
● 1: lo
Link File: /lib/systemd/network/99-default.link
Network File: n/a
Type: loopback
State: carrier (unmanaged)
Address: 127.0.0.1
::1
● 2: ens3
Link File: /lib/systemd/network/99-default.link
Network File: /run/systemd/network/10-netplan-ens3.network
Type: ether
State: routable (configured)
Path: pci-0000:00:03.0
Driver: virtio_net
Vendor: Red Hat, Inc.
Model: Virtio network device
HW Address: fa:16:3e:82:c5:fe
Address: 10.52.16.185
2001:1600:4:8:f816:3eff:fe82:c5fe
fe80::f816:3eff:fe82:c5fe
Gateway: 10.52.16.1
fe80::f816:3eff:fee7:1ea5
DNS: XX.XX.XX.XX
YY.YY.YY.YY
Search Domains: myprovider.ext
到目前为止我所做的：
第一步是创建一个桥接口br0。自从我运行 Ubuntu 18 以来，我应该为此使用 Netplan。
Netplan中的初始配置/etc/netplan/50-cloud-init.yaml是：
network:
version: 2
ethernets:
ens3:
dhcp4: true
match:
macaddress: fa:16:3e:82:c5:fe
mtu: 8950
set-name: ens3
我用这个配置做了很多测试，但我的桥接接口 (br0) 无法获得 IP。我最终使用 NetworkManager 作为渲染器，并且以下/etc/netplan/50-cloud-init.yaml配置有效：
network:
version: 2
renderer: NetworkManager
ethernets:
ens3:
dhcp4: false
dhcp6: false
match:
macaddress: fa:16:3e:82:c5:fe
set-name: ens3
mtu: 8950
bridges:
br0:
interfaces: [ens3]
dhcp4: true
dhcp6: false
mtu: 8950
parameters:
stp: true
forward-delay: 4
使用 Netplan 的输出ifconfig -a是：
br0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 8950
inet 10.52.16.185 netmask 255.255.255.0 broadcast 10.52.16.255
inet6 fe80::f816:3eff:fe82:c5fe prefixlen 64 scopeid 0x20<link>
inet6 2001:1600:4:8:f816:3eff:fe82:c5fe prefixlen 64 scopeid 0x0<global>
ether fa:16:3e:82:c5:fe txqueuelen 1000 (Ethernet)
RX packets 6364 bytes 468754 (468.7 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 75 bytes 11528 (11.5 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
ens3: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 8950
ether fa:16:3e:82:c5:fe txqueuelen 1000 (Ethernet)
RX packets 8132 bytes 713045 (713.0 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 114 bytes 13490 (13.4 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 176 bytes 11840 (11.8 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 176 bytes 11840 (11.8 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
使用 Netplan的输出ip route是：
10.52.11.0/24 dev br0 proto dhcp scope link metric 425
10.52.16.0/24 dev br0 proto kernel scope link src 10.52.16.185 metric 425
10.52.20.0/24 dev br0 proto dhcp scope link metric 425
10.52.24.0/24 dev br0 proto dhcp scope link metric 425
169.254.169.254 via 10.52.16.1 dev br0 proto dhcp metric 425
使用 Netplan的输出lspci是：
00:00.0 Host bridge: Intel Corporation 440FX - 82441FX PMC [Natoma] (rev 02)
00:01.0 ISA bridge: Intel Corporation 82371SB PIIX3 ISA [Natoma/Triton II]
00:01.1 IDE interface: Intel Corporation 82371SB PIIX3 IDE [Natoma/Triton II]
00:01.2 USB controller: Intel Corporation 82371SB PIIX3 USB [Natoma/Triton II] (rev 01)
00:01.3 Bridge: Intel Corporation 82371AB/EB/MB PIIX4 ACPI (rev 03)
00:02.0 VGA compatible controller: Cirrus Logic GD 5446
00:03.0 Ethernet controller: Red Hat, Inc Virtio network device
00:04.0 SCSI storage controller: Red Hat, Inc Virtio block device
00:05.0 SCSI storage controller: Red Hat, Inc Virtio block device
00:06.0 Unclassified device [00ff]: Red Hat, Inc Virtio memory balloon
使用 Netplan的输出networkctl -a status是：
● 1: lo
Link File: /lib/systemd/network/99-default.link
Network File: n/a
Type: loopback
State: carrier (unmanaged)
Address: 127.0.0.1
::1
● 2: ens3
Link File: /run/systemd/network/10-netplan-ens3.link
Network File: n/a
Type: ether
State: carrier (unmanaged)
Path: pci-0000:00:03.0
Driver: virtio_net
Vendor: Red Hat, Inc.
Model: Virtio network device
HW Address: fa:16:3e:82:c5:fe
● 3: br0
Link File: /lib/systemd/network/99-default.link
Network File: n/a
Type: ether
State: routable (unmanaged)
Driver: bridge
HW Address: fa:16:3e:82:c5:fe
Address: 10.52.16.185
2001:1600:4:8:f816:3eff:fe82:c5fe
fe80::f816:3eff:fe82:c5fe
Gateway: 10.52.16.1
fe80::f816:3eff:fee7:1ea5
来宾操作系统安装：
现在我的桥接界面看起来不错，我安装了虚拟化所需的软件包 ( qemu qemu-kvm libvirt-bin bridge-utils virt-manager) 并启动了libvirtd服务。
然后，我尝试使用virt-install以下命令安装我的第一个来宾操作系统：
$ sudo virt-install \
--name projectname \
--ram 1024 \
--vcpus 1 \
--network bridge:br0 \
--disk path=/srv/data/projectname,size=2 \
--os-type Linux \
--os-variant=ubuntu18.04 \
--location 'http://archive.ubuntu.com/ubuntu/dists/bionic/main/installer-amd64/' \
--graphics none \
--extra-args 'console=ttyS0' \
--console pty,target_type=serial
不幸的是，安装程序无法使用 DHCP 配置网络，如下所示：
网络自动配置失败
尝试安装来宾操作系统失败后的网络状态：
的输出ifconfig -a是：
br0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 8950
inet 10.52.16.185 netmask 255.255.255.0 broadcast 10.52.16.255
inet6 fe80::f816:3eff:fe82:c5fe prefixlen 64 scopeid 0x20<link>
inet6 2001:1600:4:8:f816:3eff:fe82:c5fe prefixlen 64 scopeid 0x0<global>
ether fa:16:3e:82:c5:fe txqueuelen 1000 (Ethernet)
RX packets 289453 bytes 301978563 (301.9 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 70249 bytes 7101505 (7.1 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
ens3: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 8950
ether fa:16:3e:82:c5:fe txqueuelen 1000 (Ethernet)
RX packets 294080 bytes 306373898 (306.3 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 71779 bytes 7183441 (7.1 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 332 bytes 27936 (27.9 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 332 bytes 27936 (27.9 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
virbr0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
inet 192.168.122.1 netmask 255.255.255.0 broadcast 192.168.122.255
ether 52:54:00:06:10:e5 txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
virbr0-nic: flags=4098<BROADCAST,MULTICAST> mtu 1500
ether 52:54:00:06:10:e5 txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
vnet0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 8950
inet6 fe80::fc54:ff:fe8e:6a11 prefixlen 64 scopeid 0x20<link>
ether fe:54:00:8e:6a:11 txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 1 bytes 90 (90.0 B)
TX errors 0 dropped 108892 overruns 0 carrier 0 collisions 0
的输出ip route是：
default via 10.52.16.1 dev br0 proto dhcp metric 425
10.52.11.0/24 dev br0 proto dhcp scope link metric 425
10.52.16.0/24 dev br0 proto kernel scope link src 10.52.16.185 metric 425
10.52.20.0/24 dev br0 proto dhcp scope link metric 425
10.52.24.0/24 dev br0 proto dhcp scope link metric 425
169.254.169.254 via 10.52.16.1 dev br0 proto dhcp metric 425
192.168.122.0/24 dev virbr0 proto kernel scope link src 192.168.122.1 linkdown
的输出lspci是：
00:00.0 Host bridge: Intel Corporation 440FX - 82441FX PMC [Natoma] (rev 02)
00:01.0 ISA bridge: Intel Corporation 82371SB PIIX3 ISA [Natoma/Triton II]
00:01.1 IDE interface: Intel Corporation 82371SB PIIX3 IDE [Natoma/Triton II]
00:01.2 USB controller: Intel Corporation 82371SB PIIX3 USB [Natoma/Triton II] (rev 01)
00:01.3 Bridge: Intel Corporation 82371AB/EB/MB PIIX4 ACPI (rev 03)
00:02.0 VGA compatible controller: Cirrus Logic GD 5446
00:03.0 Ethernet controller: Red Hat, Inc. Virtio network device
00:04.0 SCSI storage controller: Red Hat, Inc. Virtio block device
00:05.0 SCSI storage controller: Red Hat, Inc. Virtio block device
00:06.0 Unclassified device [00ff]: Red Hat, Inc. Virtio memory balloon
的输出networkctl -a status是：
● 1: lo
Link File: n/a
Network File: n/a
Type: loopback
State: carrier (unmanaged)
Address: 127.0.0.1
::1
● 2: ens3
Link File: n/a
Network File: n/a
Type: ether
State: carrier (unmanaged)
Path: pci-0000:00:03.0
Vendor: Red Hat, Inc.
Model: Virtio network device
HW Address: fa:16:3e:82:c5:fe
● 3: br0
Link File: n/a
Network File: n/a
Type: ether
State: routable (unmanaged)
Driver: bridge
HW Address: fa:16:3e:82:c5:fe
Address: 10.52.16.185
2001:1600:4:8:f816:3eff:fe82:c5fe
fe80::f816:3eff:fe82:c5fe
Gateway: 10.52.16.1
fe80::f816:3eff:fee7:1ea5
● 4: virbr0
Link File: /lib/systemd/network/99-default.link
Network File: n/a
Type: ether
State: no-carrier (unmanaged)
Driver: bridge
HW Address: 52:54:00:06:10:e5
Address: 192.168.122.1
● 5: virbr0-nic
Link File: /lib/systemd/network/99-default.link
Network File: n/a
Type: ether
State: off (unmanaged)
Driver: tun
HW Address: 52:54:00:06:10:e5
● 7: vnet0
Link File: /lib/systemd/network/99-default.link
Network File: n/a
Type: ether
State: degraded (unmanaged)
Driver: tun
HW Address: fe:54:00:8e:6a:11
Address: fe80::fc54:ff:fe8e:6a11
我尝试了上面相同的命令，但将 br0 替换为 virbr0。安装成功，但这看起来是错误的（基于我迄今为止看到的所有教程......）。
问题
- 我应该使用 Netplan 还是完全删除它？
- 应该使用默认的网络渲染器还是使用 NetworkManager 好？
- 我的 Netplan 配置正确吗？
- virt-install 参数是否正确？
- ...我究竟做错了什么 ？