诸如calico flannel等CNI实现，通过牺牲一些功能让网络复杂度得以大幅度降低是我极其推崇的，在云原生时代应用不再关心基础设施的场景下是一个明智之举，给网络调错带来了极大方便。
openstack与k8s放一起比较意义不大，openstack还是着重与基础设施，所以对上接口还是机器设施，网络设施，存储设施等，着重与资源的抽象。
然鹅k8s不仅需要资源抽象，还需要关心应用的管理，其基于容器的设计理念已经改变了传统三层的云计算架构，而更像一个云内核，对上不再关心基础设施的接口了，反正把用户应用管好了就行。
对比早起的操作系统很发现历史是惊人的相似，早期分层式操作系统到现代的宏内核与微内核操作系统，系统设计更为内聚了。目测云操作系统也会朝着这个路子发展吧（openstack粉太多，亡openstack之心不死不敢直说）
但是！
openstack底层一些技术还是非常值得学习与应用的，如qemu kvm ovs ovn ceph DPDK等。。。
本文重点讲网络这块,ovn ovs怎么与kubernetes擦出火花
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CNI原理简述
CNI不是本文的重点，这里仅做一下简单的介绍更多详情
CNI很简单，本质就是你实现一个命令行工具，kubelet初始化网络时会去调用这个工具，传入一些环境变量，然后根据环境变量工具去做网络配置：
配置完成后标准输出一个CNI规定的json格式，告诉k8s你的IP地址啥的
命令包含三个部分
- ADD 创建网络
- DEL 删除网络
- CHECK 检查网络
这里对ADD做一个介绍：
EnvCNIPath = "CNI_PATH"
EnvNetDir = "NETCONFPATH"
EnvCapabilityArgs = "CAP_ARGS"
EnvCNIArgs = "CNI_ARGS"
EnvCNIIfname = "CNI_IFNAME" # 网卡名
DefaultNetDir = "/etc/cni/net.d"
CmdAdd = "add"
CmdCheck = "check"
CmdDel = "del"
入参：
容器ID
网络namespace目录
网络配置 - 定义哪些容器可以join到此网络
容器内网卡名
额外参数
标准输出类似这样一个json：
{
"cniVersion": "0.4.0",
"interfaces": [ (this key omitted by IPAM plugins)
{
"name": "<name>",
"mac": "<MAC address>", (required if L2 addresses are meaningful)
"sandbox": "<netns path or hypervisor identifier>" (required for container/hypervisor interfaces, empty/omitted for host interfaces)
}
],
"ips": [
{
"version": "<4-or-6>",
"address": "<ip-and-prefix-in-CIDR>",
"gateway": "<ip-address-of-the-gateway>", (optional)
"interface": <numeric index into 'interfaces' list>
}
...
那比如想拿到pod的一些元数据怎么办，典型场景是比如pod yaml里定义了属于哪个子网啥的，对不起CNI不传给你，你得拿着podid去apiserver里查，这是一个非常不爽的地方，所以现在ovn的CNI都有一个CNI server的东西去和apiserver交互。
我去实现的话会考虑把信息写到容器的label里，这样CNI工具直接去容器元数据里查找一些信息,少用一个server
OVS与OVN安装与配置
编译安装
(吐槽一下ovn写的shit一般的文档)
推荐用源码安装地址
wget https://www.openvswitch.org/releases/openvswitch-2.11.1.tar.gz
tar zxvf openvswitch-2.11.1.tar.gz
cd openvswitch-2.11.1
./boot.sh && ./configure && make && make install
有个ovn的sandbox 可以这样make : make sandbox SANDBOXFLAGS="--ovn" 太低级咱不玩
如果编译内核模块：
$ make modules_install
$ config_file="/etc/depmod.d/openvswitch.conf"
$ for module in datapath/linux/*.ko; do
modname="$(basename ${module})"
echo "override ${modname%.ko} * extra" >> "$config_file"
echo "override ${modname%.ko} * weak-updates" >> "$config_file"
done
$ depmod -a
$ /sbin/modprobe openvswitch
$ /sbin/lsmod | grep openvswitch
启动ovs
$ export PATH=$PATH:/usr/local/share/openvswitch/scripts
$ ovs-ctl start --system-id="random"
$ ovs-appctl -t ovsdb-server ovsdb-server/add-remote ptcp:6640:IP_ADDRESS # 开启远程数据库
IP_ADDRESS 是控制节点管理网地址
验证ovs
$ ovs-vsctl add-br br0
$ ovs-vsctl add-port br0 eth0
$ ovs-vsctl add-port br0 vif1.0
$ ovs-vsctl show
启动ovn
$ /usr/share/openvswitch/scripts/ovn-ctl start_northd # 启动北向数据库
$ /usr/share/openvswitch/scripts/ovn-ctl start_controller # 启动ovn controller
$ ovn-sbctl show # 验证
$ ovn-nbctl show # 验证
配置ovs与ovn相连接
# ovn-nbctl set-connection ptcp:6641:0.0.0.0 -- \
set connection . inactivity_probe=60000
# ovn-sbctl set-connection ptcp:6642:0.0.0.0 -- \
set connection . inactivity_probe=60000
# if using the VTEP functionality:
# ovs-appctl -t ovsdb-server ovsdb-server/add-remote ptcp:6640:0.0.0.0
配置ovsdb-server模块，默认ovsdb-server只允许本地访问，ovn服务需要这个权限。
配置ovs
controller节点使用ovs databases
ovs-vsctl set open . external-ids:ovn-remote=tcp:IP_ADDRESS:6642
ovs-vsctl set open . external-ids:ovn-encap-type=geneve,vxlan # 配置封装类型，geneve比较吊
ovs-vsctl set open . external-ids:ovn-encap-ip=IP_ADDRESS # 配置overlay endpoint地址
OVS与容器
ovs单机连通性
创建容器, 设置net=none可以防止docker0默认网桥影响连通性测试
docker run -itd --name con6 --net=none ubuntu:14.04 /bin/bash
docker run -itd --name con7 --net=none ubuntu:14.04 /bin/bash
docker run -itd --name con8 --net=none ubuntu:14.04 /bin/bash
创建网桥
ovs-vsctl add-br ovs0
使用ovs-docker给容器添加网卡，并挂到ovs0网桥上
ovs-docker add-port ovs0 eth0 con6 --ipaddress=192.168.1.2/24
ovs-docker add-port ovs0 eth0 con7 --ipaddress=192.168.1.3/24
ovs-docker add-port ovs0 eth0 con8 --ipaddress=192.168.1.4/24
查看网桥
[root@controller /]# ovs-vsctl show
21e4d4c5-cadd-4dac-b025-c20b8108ad09
Bridge "ovs0"
Port "b167e3dcf8db4_l"
Interface "b167e3dcf8db4_l"
Port "f1c0a9d0994d4_l"
Interface "f1c0a9d0994d4_l"
Port "121c6b2f221c4_l"
Interface "121c6b2f221c4_l"
Port "ovs0"
Interface "ovs0"
type: internal
ovs_version: "2.8.2"
测试连通性
[root@controller /]# docker exec -it con8 sh
# ping 192.168.1.2
PING 192.168.1.2 (192.168.1.2) 56(84) bytes of data.
64 bytes from 192.168.1.2: icmp_seq=1 ttl=64 time=0.886 ms
^C
--- 192.168.1.2 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.886/0.886/0.886/0.000 ms
#
# ping 192.168.1.3
PING 192.168.1.3 (192.168.1.3) 56(84) bytes of data.
64 bytes from 192.168.1.3: icmp_seq=1 ttl=64 time=0.712 ms
^C
--- 192.168.1.3 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.712/0.712/0.712/0.000 ms
#
设置VLAN tag
查看网桥
[root@controller /]# ovs-vsctl show
21e4d4c5-cadd-4dac-b025-c20b8108ad09
Bridge "ovs0"
Port "b167e3dcf8db4_l"
Interface "b167e3dcf8db4_l"
Port "f1c0a9d0994d4_l"
Interface "f1c0a9d0994d4_l"
Port "121c6b2f221c4_l"
Interface "121c6b2f221c4_l"
Port "ovs0"
Interface "ovs0"
type: internal
ovs_version: "2.8.2"
Interface是openvswitch核心概念之一，对应模拟的是交换机中插入port的网卡设备。一个Port通常只能有一个interface，但也可以有多个interfaces(Bond).
interface type
- system(如eth0),比如想把系统上的网卡挂在网桥上
- internal(模拟网络设备，名字如果是和bridge的名字一样则叫local interface)
- tap(一个tun/tap设备)
- patch(一对虚拟设备，用来模拟插线电缆) 容器场景用的多
- geneve(以太网通过geneve隧道)
- gre(RFC2890)，ipsec_gre(RFC2890 over ipsec tunnel)
- vxlan(基于以UDP为基础的VXLAN协议上的以太网隧道)
- lisp(一个3层的隧道，还在实验阶段)
- stt（Stateless TCP Tunnel，）
查看interface
[root@controller /]# ovs-vsctl list interface f1c0a9d0994d4_l
_uuid : cf400e7c-d2d6-4e0a-ad02-663dd63d1751
admin_state : up
duplex : full
error : []
external_ids : {container_id="con6", container_iface="eth0"}
ifindex : 239
ingress_policing_burst: 0
ingress_policing_rate: 0
lacp_current : []
link_resets : 1
link_speed : 10000000000
link_state : up
mac_in_use : "96:91:0a:c9:02:d6"
mtu : 1500
mtu_request : []
name : "f1c0a9d0994d4_l"
ofport : 3
other_config : {}
statistics : {collisions=0, rx_bytes=1328, rx_crc_err=0, rx_dropped=0, rx_errors=0, rx_frame_err=0, rx_over_err=0, rx_packets=18, tx_bytes=3032, tx_dropped=0, tx_errors=0, tx_packets=40}
status : {driver_name=veth, driver_version="1.0", firmware_version=""}
type : ""
设置vlan tag
ovs-vsctl set port f1c0a9d0994d4_l tag=100 //con6
ovs-vsctl set port b167e3dcf8db4_l tag=100 //con8
ovs-vsctl set port 121c6b2f221c4_l tag=200 //con7
测试连通性
[root@controller /]# docker exec -it con8 sh
#
# ping 192.168.1.2 -c 3
PING 192.168.1.2 (192.168.1.2) 56(84) bytes of data.
64 bytes from 192.168.1.2: icmp_seq=1 ttl=64 time=0.413 ms
64 bytes from 192.168.1.2: icmp_seq=2 ttl=64 time=0.061 ms
64 bytes from 192.168.1.2: icmp_seq=3 ttl=64 time=0.057 ms
--- 192.168.1.2 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2044ms
rtt min/avg/max/mdev = 0.057/0.177/0.413/0.166 ms
#
# ping 192.168.1.3 -c 3
PING 192.168.1.3 (192.168.1.3) 56(84) bytes of data.
From 192.168.1.4 icmp_seq=1 Destination Host Unreachable
From 192.168.1.4 icmp_seq=2 Destination Host Unreachable
--- 192.168.1.3 ping statistics ---
3 packets transmitted, 0 received, +3 errors, 100% packet loss, time 2068ms
pipe 3
#
跨主机连通性
环境
host1 172.29.101.123
网桥: ovs0
容器:
con6 192.168.1.2
con7 192.168.1.3
con8 192.168.1.4
创建方式依上
host2 172.29.101.82
网桥: ovs1
容器: con11
准备环境
创建网桥
ovs-vsctl add-br ovs1
创建容器
docker run -itd --name con11 --net=none ubuntu:14.04 /bin/bash
挂到ovs0网桥
ovs-docker add-port ovs1 eth0 con11 --ipaddress=192.168.1.6/24
查看网桥ovs1
[root@compute82 /]# ovs-vsctl show
380ce027-8edf-4844-8e89-a6b9c1adaff3
Bridge "ovs1"
Port "0384251973e64_l"
Interface "0384251973e64_l"
Port "ovs1"
Interface "ovs1"
type: internal
ovs_version: "2.8.2"
设置vxlan
在host1上
[root@controller /]# ovs-vsctl add-port ovs0 vxlan1 -- set interface vxlan1 type=vxlan options:remote_ip=172.29.101.82 options:key=flow
[root@controller /]#
[root@controller /]# ovs-vsctl show
21e4d4c5-cadd-4dac-b025-c20b8108ad09
Bridge "ovs0"
Port "b167e3dcf8db4_l"
tag: 100
Interface "b167e3dcf8db4_l"
Port "f1c0a9d0994d4_l"
tag: 100
Interface "f1c0a9d0994d4_l"
Port "121c6b2f221c4_l"
tag: 200
Interface "121c6b2f221c4_l"
Port "ovs0"
Interface "ovs0"
type: internal
Port "vxlan1"
Interface "vxlan1"
type: vxlan
options: {key=flow, remote_ip="172.29.101.82"}
ovs_version: "2.8.2"
在host2上
[root@compute82 /]# ovs-vsctl add-port ovs1 vxlan1 -- set interface vxlan1 type=vxlan options:remote_ip=172.29.101.123 options:key=flow
[root@compute82 /]#
[root@compute82 /]# ovs-vsctl show
380ce027-8edf-4844-8e89-a6b9c1adaff3
Bridge "ovs1"
Port "0384251973e64_l"
Interface "0384251973e64_l"
Port "vxlan1"
Interface "vxlan1"
type: vxlan
options: {key=flow, remote_ip="172.29.101.123"}
Port "ovs1"
Interface "ovs1"
type: internal
ovs_version: "2.8.2"
设置vlan tag
ovs-vsctl set port 0384251973e64_l tag=100
连通性测试
[root@compute82 /]# docker exec -ti con11 bash
root@c82da61bf925:/# ping 192.168.1.2
PING 192.168.1.2 (192.168.1.2) 56(84) bytes of data.
64 bytes from 192.168.1.2: icmp_seq=1 ttl=64 time=0.161 ms
64 bytes from 192.168.1.2: icmp_seq=2 ttl=64 time=0.206 ms
^C
--- 192.168.1.2 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1000ms
root@c82da61bf925:/#
root@c82da61bf925:/# ping 192.168.1.3
PING 192.168.1.3 (192.168.1.3) 56(84) bytes of data.
^C
--- 192.168.1.3 ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 2027ms
root@c82da61bf925:/#
root@c82da61bf925:/# exit
结论
vxlan只能连通两台机器的ovs上同一个网段的容器，无法连通ovs上不同网段的容器。如果需要连通不同网段的容器，接下来我们尝试通过ovs的流表来解决这个问题。
OpenFlow
flow table
支持openflow的交换机中可能包含多个flow table。每个flow table包含多条规则，每条规则包含匹配条件和执行动作。flow table中的每条规则有优先级，优先级高的优先匹配，匹配到规则以后，执行action，如果匹配失败，按优先级高低，继续匹配下一条。如果都不匹配，每张表会有默认的动作，一般为drop或者转给下一张流表。
实践
环境
host1 172.29.101.123
网桥: ovs0
容器:
con6 192.168.1.2 tag=100
con7 192.168.1.3 tag=100
host2 172.29.101.82
网桥: ovs1
容器:
con9: 192.168.2.2 tag=100
con10：192.168.2.3 tag=100
con11: 192.168.1.5 tag=100
查看默认流表
在host1上查看默认流表
[root@controller msxu]# ovs-ofctl dump-flows ovs0
cookie=0x0, duration=27858.050s, table=0, n_packets=5253660876, n_bytes=371729202788, priority=0 actions=NORMAL
在容器con6中ping con7，网络连通
[root@controller /]# docker exec -ti con6 bash
root@9ccc5c5664f9:/#
root@9ccc5c5664f9:/# ping 192.168.1.3
PING 192.168.1.3 (192.168.1.3) 56(84) bytes of data.
64 bytes from 192.168.1.3: icmp_seq=1 ttl=64 time=0.613 ms
64 bytes from 192.168.1.3: icmp_seq=2 ttl=64 time=0.066 ms
--- 192.168.1.3 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1058ms
rtt min/avg/max/mdev = 0.066/0.339/0.613/0.274 ms
root@9ccc5c5664f9:/#
删除默认流表
[root@controller /]# ovs-ofctl del-flows ovs0
[root@controller /]#
[root@controller /]# ovs-ofctl dump-flows ovs0
[root@controller /]#
测试网络连通性，发现网络已经不通
[root@controller /]# docker exec -ti con6 bash
root@9ccc5c5664f9:/#
root@9ccc5c5664f9:/# ping 192.168.1.3
PING 192.168.1.3 (192.168.1.3) 56(84) bytes of data.
^C
--- 192.168.1.3 ping statistics ---
2 packets transmitted, 0 received, 100% packet loss, time 1025ms
root@9ccc5c5664f9:/#
添加流表
如果要con6和con7能够通信，需要建立规则，让ovs转发对应的数据
查看con6和con7在ovs上的网络端口
[root@controller /]# ovs-vsctl show
21e4d4c5-cadd-4dac-b025-c20b8108ad09
Bridge "ovs0"
Port "f1c0a9d0994d4_l"
tag: 100
Interface "f1c0a9d0994d4_l"
Port "121c6b2f221c4_l"
tag: 100
Interface "121c6b2f221c4_l"
Port "ovs0"
Interface "ovs0"
type: internal
Port "vxlan1"
Interface "vxlan1"
type: vxlan
options: {key=flow, remote_ip="172.29.101.82"}
ovs_version: "2.8.2"
[root@controller /]# ovs-vsctl list interface f1c0a9d0994d4_l |grep ofport
ofport : 3
ofport_request : []
[root@controller /]#
[root@controller /]# ovs-vsctl list interface 121c6b2f221c4_l |grep ofport
ofport : 4
ofport_request : []
添加规则：
[root@controller /]#ovs-ofctl add-flow ovs0 "priority=1,in_port=3,actions=output:4"
[root@controller /]#ovs-ofctl add-flow ovs0 "priority=2,in_port=4,actions=output:3"
[root@controller /]# ovs-ofctl dump-flows ovs0
cookie=0x0, duration=60.440s, table=0, n_packets=0, n_bytes=0, priority=1,in_port="f1c0a9d0994d4_l" actions=output:"121c6b2f221c4_l"
cookie=0x0, duration=50.791s, table=0, n_packets=0, n_bytes=0, priority=1,in_port="121c6b2f221c4_l" actions=output:"f1c0a9d0994d4_l"
[root@controller /]#
测试连通性：con6和con7已通
[root@controller msxu]# docker exec -ti con6 bash
root@9ccc5c5664f9:/# ping 192.168.1.3
PING 192.168.1.3 (192.168.1.3) 56(84) bytes of data.
64 bytes from 192.168.1.3: icmp_seq=1 ttl=64 time=0.924 ms
64 bytes from 192.168.1.3: icmp_seq=2 ttl=64 time=0.058 ms
^C
--- 192.168.1.3 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1057ms
rtt min/avg/max/mdev = 0.058/0.491/0.924/0.433 ms
root@9ccc5c5664f9:/#
设置一条优先级高的规则：
[root@controller /]# ovs-ofctl add-flow ovs0 "priority=2,in_port=4,actions=drop"
[root@controller /]#
[root@controller /]# docker exec -ti con6 bash
root@9ccc5c5664f9:/#
root@9ccc5c5664f9:/# ping 192.168.1.3
PING 192.168.1.3 (192.168.1.3) 56(84) bytes of data.
^C
--- 192.168.1.3 ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 2087ms
root@9ccc5c5664f9:/#
root@9ccc5c5664f9:/#
流表中的规则是有优先级的，priority数值越大，优先级越高。流表中，优先级高的优先匹配，并执行匹配规则的actions。如果不匹配，继续匹配优先级低的下一条。
跨网段连通
在上一个vxlan的实践中，通过设置vxlan可以打通两个机器上的ovs，但我们提到两个机器ovs上的容器得在同一个网段上才能通信。
在ip为192.168.2.2的con9上ping另一台机上的con6 192.168.1.2
[root@compute82 /]# docker exec -ti con9 bash
root@b55602aad0ac:/#
root@b55602aad0ac:/# ping 192.168.1.2
connect: Network is unreachable
root@b55602aad0ac:/#
添加流表规则：
在host1上：
[root@controller /]# ovs-ofctl add-flow ovs0 "priority=4,in_port=6,actions=output:3"
[root@controller /]#
[root@controller /]# ovs-ofctl add-flow ovs0 "priority=4,in_port=3,actions=output:6"
[root@controller /]# ovs-ofctl dump-flows ovs0
cookie=0x0, duration=3228.737s, table=0, n_packets=7, n_bytes=490, priority=1,in_port="f1c0a9d0994d4_l" actions=output:"121c6b2f221c4_l"
cookie=0x0, duration=3215.544s, table=0, n_packets=0, n_bytes=0, priority=1,in_port="121c6b2f221c4_l" actions=output:"f1c0a9d0994d4_l"
cookie=0x0, duration=3168.297s, table=0, n_packets=9, n_bytes=546, priority=2,in_port="121c6b2f221c4_l" actions=drop
cookie=0x0, duration=12.024s, table=0, n_packets=0, n_bytes=0, priority=4,in_port=vxlan1 actions=output:"f1c0a9d0994d4_l"
cookie=0x0, duration=3.168s, table=0, n_packets=0, n_bytes=0, priority=4,in_port="f1c0a9d0994d4_l" actions=output:vxlan1
在host2上
[root@compute82 /]# ovs-ofctl add-flow ovs1 "priority=1,in_port=1,actions=output:6"
[root@compute82 /]#
[root@compute82 /]# ovs-ofctl add-flow ovs1 "priority=1,in_port=6,actions=output:1"
[root@compute82 /]# ovs-ofctl dump-flows ovs1
cookie=0x0, duration=1076.522s, table=0, n_packets=27, n_bytes=1134, priority=1,in_port="0384251973e64_l" actions=output:vxlan1
cookie=0x0, duration=936.403s, table=0, n_packets=0, n_bytes=0, priority=1,in_port=vxlan1 actions=output:"0384251973e64_l"
cookie=0x0, duration=70205.443s, table=0, n_packets=7325, n_bytes=740137, priority=0 actions=NORMAL
测试连通性
在host2 con9上ping 192.168.1.2
[root@compute82 /]# docker exec -ti con9 bash
root@b55602aad0ac:/#
root@b55602aad0ac:/# ping 192.168.1.2
connect: Network is unreachable
root@b55602aad0ac:/#
发现网络并不通，查看发现路由规则有问题，添加默认路由规则，注意这里需要已privileged权限进入容器
[root@compute82 /]# docker exec --privileged -ti con9 bash
root@b55602aad0ac:/#
root@b55602aad0ac:/# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.2.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
root@b55602aad0ac:/# route add default dev eth0
root@b55602aad0ac:/#
root@b55602aad0ac:/# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 0.0.0.0 0.0.0.0 U 0 0 0 eth0
192.168.2.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
root@b55602aad0ac:/#
在host1和host2的容器中都添加好路由规则后，测试连通性
[root@compute82 /]# docker exec --privileged -ti con9 bash
root@b55602aad0ac:/#
root@b55602aad0ac:/# ping 192.168.1.2
PING 192.168.1.2 (192.168.1.2) 56(84) bytes of data.
64 bytes from 192.168.1.2: icmp_seq=1 ttl=64 time=1.16 ms
64 bytes from 192.168.1.2: icmp_seq=2 ttl=64 time=0.314 ms
^C
--- 192.168.1.2 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1002ms
rtt min/avg/max/mdev = 0.314/0.739/1.165/0.426 ms
已成功通过ovs，vxlan打通两台机器上不同网段容器
OVN实践
有了ovs相关的实践，就具备了一定的基础，下面就可以进一步去了解ovn，ovn很重要的一点就是理解逻辑交换机,ovn是管控层面的，比如每台机器上都起了一个ovs交换机（软交换机，或者相对于逻辑交换机称之为物理交换机) 分布在不同机器上的虚拟机想要在一个子网下，那么我们创建一个逻辑交换机，把机器interface与之逻辑上关联在一起即可，最终ovn会下发流表使其在一个子网下。
基本使用
逻辑面（控制面）
创建俩逻辑交换机
$ ovn-nbctl ls-add sw0
$ ovn-nbctl lsp-add sw0 sw0-port1
$ ovn-nbctl lsp-set-addresses sw0-port1 "50:54:00:00:00:01 192.168.0.2"
$ ovn-nbctl ls-add sw1
$ ovn-nbctl lsp-add sw1 sw1-port1
$ ovn-nbctl lsp-set-addresses sw1-port1 "50:54:00:00:00:03 11.0.0.2"
创建一个逻辑路由器，并把两个交换机连接到路由器上
$ ovn-nbctl lr-add lr0
$ ovn-nbctl lrp-add lr0 lrp0 00:00:00:00:ff:01 192.168.0.1/24
$ ovn-nbctl lsp-add sw0 lrp0-attachment
$ ovn-nbctl lsp-set-type lrp0-attachment router
$ ovn-nbctl lsp-set-addresses lrp0-attachment 00:00:00:00:ff:01
$ ovn-nbctl lsp-set-options lrp0-attachment router-port=lrp0
$ ovn-nbctl lrp-add lr0 lrp1 00:00:00:00:ff:02 11.0.0.1/24
$ ovn-nbctl lsp-add sw1 lrp1-attachment
$ ovn-nbctl lsp-set-type lrp1-attachment router
$ ovn-nbctl lsp-set-addresses lrp1-attachment 00:00:00:00:ff:02
$ ovn-nbctl lsp-set-options lrp1-attachment router-port=lrp1
查看逻辑配置：
$ ovn-nbctl show
switch 1396cf55-d176-4082-9a55-1c06cef626e4 (sw1)
port lrp1-attachment
addresses: ["00:00:00:00:ff:02"]
port sw1-port1
addresses: ["50:54:00:00:00:03 11.0.0.2"]
switch 2c9d6d03-09fc-4e32-8da6-305f129b0d53 (sw0)
port lrp0-attachment
addresses: ["00:00:00:00:ff:01"]
port sw0-port1
addresses: ["50:54:00:00:00:01 192.168.0.2"]
router f8377e8c-f75e-4fc8-8751-f3ea03c6dd98 (lr0)
port lrp0
mac: "00:00:00:00:ff:01"
networks: ["192.168.0.1/24"]
port lrp1
mac: "00:00:00:00:ff:02"
networks: ["11.0.0.1/24"]
使用ovn-trace:
$ ovn-trace --minimal sw0 'inport == "sw0-port1" \
> && eth.src == 50:54:00:00:00:01 && ip4.src == 192.168.0.2 \
> && eth.dst == 00:00:00:00:ff:01 && ip4.dst == 11.0.0.2 \
> && ip.ttl == 64'
# ip,reg14=0x1,vlan_tci=0x0000,dl_src=50:54:00:00:00:01,dl_dst=00:00:00:00:ff:01,nw_src=192.168.0.2,nw_dst=11.0.0.2,nw_proto=0,nw_tos=0,nw_ecn=0,nw_ttl=64
ip.ttl--;
eth.src = 00:00:00:00:ff:02;
eth.dst = 50:54:00:00:00:03;
output("sw1-port1");
这里我们指定了源地址与源端口，再指定目的ip，最后会输出告诉我们从交换机哪个端口发出去了。
重点: 把容器挂到逻辑交换机上
ovs-docker这个工具里有这样一句：
ip link add "${PORTNAME}_l" type veth peer name "${PORTNAME}_c"
# Add one end of veth to OVS bridge.
if ovs_vsctl --may-exist add-port "$BRIDGE" "${PORTNAME}_l" \
-- set interface "${PORTNAME}_l" \
先创建了一个设备对，然后把设备对一端设置成ovs上的一个interface, 这样容器与ovs就关联上了，再把这个ovs上的port与ovn逻辑子网进行关联即可，请看具体例子：
启动容器后是先要把容器设备对的一端挂在物理交换机上，然后通过设置iface-id来与逻辑交换机进行关联。
ovs-vsctl --may-exist add-port sw0 port0 -- set interface port0 # 把docker挂到ovs上
ovs-vsctl set Interface port0 external_ids:iface-id=lpor0 # 通过iface-id关联到逻辑端口上
具体代码可以查看这里 这封装了一些基操作
一些具体实现：使用教程
逻辑子网
这里创建四个端口，都挂在ovs br-int网桥上，但是分别属于不同的逻辑交换机，这样不同的逻辑交换机没有连接路由器的情况下是不通的，同一个逻辑子网下端口可以互通。
ls-create sw0
ls-add-port sw0 sw0-port1 00:00:00:00:00:01 192.168.33.10/24
ls-add-port sw0 sw0-port2 00:00:00:00:00:02 192.168.33.20/24
ls-create sw1
ls-add-port sw1 sw1-port1 00:00:00:00:00:03 192.168.33.30/24
ls-add-port sw1 sw1-port2 00:00:00:00:00:04 192.168.33.40/24
ovs-add-port br-int lport1 sw0-port1 192.168.33.1
ovs-add-port br-int lport2 sw0-port2 192.168.33.1
ovs-add-port br-int lport3 sw1-port1 192.168.33.1
ovs-add-port br-int lport4 sw1-port2 192.168.33.1
ip netns exec lport1-ns ip addr
ip netns exec lport2-ns ip addr
ip netns exec lport3-ns ip addr
ip netns exec lport4-ns ip addr
ip netns exec lport1-ns ping -c3 192.168.33.20
ofport=$(ovs-vsctl list interface lport1 | awk '/ofport /{print $3}')
ovs-appctl ofproto/trace br-int in_port=$ofport,dl_src=00:00:00:00:00:01,dl_dst=00:00:00:00:00:02 -generate
ip netns exec lport1-ns ping -c3 192.168.33.30
ovs-appctl ofproto/trace br-int in_port=$ofport,dl_src=00:00:00:00:00:01,dl_dst=00:00:00:00:00:03 -generate
这里ls-create ls-add-port和ovs-add-port是简单封装了一下命令：
ls-create ls-add-port:
ls-create() {
ovn-nbctl --may-exist ls-add $switch
}
ls-add-port() {
switch=$1
port=$2
mac=$3
cidr=$4
# 逻辑交换机上创建逻辑端口
ovn-nbctl --may-exist lsp-add $switch $port
# 给逻辑端口设置mac地址
ovn-nbctl lsp-set-addresses $port $mac
# 仅允许该端口源或目的mac为对应地址
ovn-nbctl lsp-set-port-security $port $mac $cidr
}
穿件网络ns，把interface塞到ns中，再与物理端口相关联，然后给interface配置IP
ovs-add-port() {
bridge=$1
port=$2
lport=$3
gateway=$4
# 创建一个网络ns
ip netns add $port-ns
# set interface 很重要，要不然就会只有端口没有interface,所以无法把它塞到ns中
ovs-vsctl --may-exist add-port $bridge $port -- set interface $port type=internal
if [ ! -z "$lport" ]; then
# 把逻辑端口与ovs端口进行关联
ovs-vsctl set Interface $port external_ids:iface-id=$lport
fi
pscount=$(ovn-nbctl lsp-get-port-security $lport | wc -l)
if [ $pscount = 2 ]; then
mac=$(ovn-nbctl lsp-get-port-security $lport | head -n 1)
cidr=$(ovn-nbctl lsp-get-port-security $lport | tail -n 1)
ip link set $port netns $port-ns
# ip netns exec $port-ns ip link set dev $port name eth0
ip netns exec $port-ns ip link set $port address $mac
ip netns exec $port-ns ip addr add $cidr dev $port
ip netns exec $port-ns ip link set $port up
if [ ! -z "$gateway" ]; then
ip netns exec $port-ns ip route add default via $gateway
fi
fi
}
所以在实现专有网络时只需要创建不同的逻辑交换机即可，不通过路由相连专有网络之间就会相互隔离。
IP管理（DHCP）
静态IP配置
这里给ovn逻辑端口配置一个静态的IP，然后ovn会模拟DHCP协议给端口响应完成地址配置
ovn-nbctl lr-add user1
ovn-nbctl ls-add vpc1
#创建路由连接到vpc1端口，并分配mac 02:ac:10:ff:34:01 IP 172.66.1.10
ovn-nbctl lrp-add user1 user1-vpc1 02:ac:10:ff:34:01 172.66.1.10/24
ovn-nbctl lsp-add vpc1 vpc1-user1
ovn-nbctl lsp-set-type vpc1-user1 router
ovn-nbctl lsp-set-addresses vpc1-user1 02:ac:10:ff:34:01
ovn-nbctl lsp-set-options vpc1-user1 router-port=user1-vpc1
#创建路由连接到vpc2端口，并分配mac 02:ac:10:ff:34:02 IP 172.77.1.10
ovn-nbctl lrp-add user1 user1-vpc2 02:ac:10:ff:34:02 172.77.1.10/24
ovn-nbctl lsp-add vpc1 vpc1-vm1
# 这里给逻辑端口配置IP地址
ovn-nbctl lsp-set-addresses vpc1-vm1 "02:ac:10:ff:01:30 172.66.1.107"
# ovn-nbctl lsp-set-port-security vpc1-vm1 "02:ac:10:ff:01:30 172.66.1.101"
options=$(ovn-nbctl create DHCP_Options cidr=172.66.1.0/24 \
options="\"server_id\"=\"172.66.1.10\" \"server_mac\"=\"02:ac:10:ff:34:01\" \
\"lease_time\"=\"3600\" \"router\"=\"172.66.1.10\"")
echo "DHCP options is: " $options
ovn-nbctl lsp-set-dhcpv4-options vpc1-vm1 $options
ovn-nbctl lsp-get-dhcpv4-options vpc1-vm1
ip netns add vm1
ovs-vsctl add-port br-int vm1 -- set interface vm1 type=internal
ip link set vm1 address 02:ac:10:ff:01:30
ip link set vm1 netns vm1
ovs-vsctl set Interface vm1 external_ids:iface-id=vpc1-vm1
# 通过DHCP即可拿到地址
ip netns exec vm1 dhclient vm1
ip netns exec vm1 ip addr show vm1
ip netns exec vm1 ip route show
clean() {
ip netns del vm1
ovn-nbctl ls-del vpc1
ovs-vsctl del-port br-int vm1
}
动态获取IP地址
ovn支持管理你的IP地址，只需要指定一个子网，就会给借口分配未被占用的IP地址：
大部分操作与静态IP一样，注意下面几个重点注释地方：
ovn-nbctl lr-add user1
ovn-nbctl ls-add vpc1
# [重点] 需要other_config，否则不会分配地址
ovn-nbctl set Logical_Switch vpc1 other_config:subnet=172.66.1.10/24
#创建路由连接到vpc1端口，并分配mac 02:ac:10:ff:34:01 IP 172.66.1.10
ovn-nbctl lrp-add user1 user1-vpc1 02:ac:10:ff:34:01 172.66.1.10/24
ovn-nbctl lsp-add vpc1 vpc1-user1
ovn-nbctl lsp-set-type vpc1-user1 router
ovn-nbctl lsp-set-addresses vpc1-user1 02:ac:10:ff:34:01
ovn-nbctl lsp-set-options vpc1-user1 router-port=user1-vpc1
ovn-nbctl lsp-add vpc1 vpc1-vm1
# 【重点】这里不指定具体地址，而使用dynamic
ovn-nbctl lsp-set-addresses vpc1-vm1 "02:ac:10:ff:01:30 dynamic"
# ovn-nbctl lsp-set-addresses vpc1-vm1 "dynamic"
# ovn-nbctl lsp-set-port-security vpc1-vm1 "02:ac:10:ff:01:30 172.66.1.106"
options=$(ovn-nbctl create DHCP_Options cidr=172.66.1.0/24 \
options="\"server_id\"=\"172.66.1.10\" \"server_mac\"=\"02:ac:10:ff:34:01\" \
\"lease_time\"=\"3600\" \"router\"=\"172.66.1.10\"")
echo "DHCP options is: " $options
ovn-nbctl lsp-set-dhcpv4-options vpc1-vm1 $options
ovn-nbctl lsp-get-dhcpv4-options vpc1-vm1
# 这里可以看到分配到的地址
ovn-nbctl list logical_switch_port
ip netns add vm1
ovs-vsctl add-port br-int vm1 -- set interface vm1 type=internal
ip link set vm1 address 02:ac:10:ff:01:30
ip link set vm1 netns vm1
ovs-vsctl set Interface vm1 external_ids:iface-id=vpc1-vm1
# 通过dhclient就可以获取到地址了
ip netns exec vm1 dhclient vm1
ip netns exec vm1 ip addr show vm1
ip netns exec vm1 ip route show
经典网络实现
ovn-nbctl lsp-add out outs-wan
ovn-nbctl lsp-set-addresses outs-wan unknown
ovn-nbctl lsp-set-type outs-wan localnet # 连接物理网络端口类型
ovn-nbctl lsp-set-options outs-wan network_name=wanNet # 做bridge mapping时需要
ovs-vsctl add-br br-eth
ovs-vsctl set Open_vSwitch . external-ids:ovn-bridge-mappings=wanNet:br-eth
ovs-vsctl add-port br-eth eth0
#配置网桥IP
ip link set br-eth up
ip addr add 192.168.66.111/23 dev br-eth
把虚拟机关联到逻辑网桥上，这样物理网卡与虚拟机就在一个网桥上了
ovs-vsctl set Interface vm1 external_ids:iface-id=vm1
FIP实现
其它部分的链接参考上文，这里主要是路由相关的操作
vm想要出网那么必须要进行源地址转换，就和我们访问google一样，那我们机器的192.168.x.x的地址就会在路由器上被转化
#对vpc1
ovn-nbctl -- --id=@nat create nat type="snat" logical_ip=172.66.1.0/24 \
external_ip=192.168.66.45 -- add logical_router gateway_route nat @nat
#会返回uuid
56ad6c5b-8417-4314-95c4-a0d780b5ef0b
这里66.45是我们链接物理网络的一个地址，告诉路由器使用该地址进行转换
实现FIP其实就是snat dnat都做：
#对vm3 172.66.1.103 绑定外网 192.168.66.46
ovn-nbctl -- --id=@nat create nat type="dnat_and_snat" logical_ip=172.66.1.103 \
external_ip=192.168.66.46 -- add logical_router gateway_route nat @nat
ovn ovs与CNI对接
ovn ovs与CNI对接包含两个部分，CNI插件仅需要把容器的设备对一端挂载到ovs网桥上然后配置好地址,与逻辑端口做好映射. 主要是物理面的功能，逻辑管控层面就可以通过CRD进行创建，所以重点是对ovn ovs CNI本身的掌握。
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