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,我们是想利用k8s管理重量级虚拟机才会研究这块东西,社区这块虽然有一些项目但都一定程度上不满足需求)
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
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:
代码语言:javascript复制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:
代码语言:javascript复制容器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:
代码语言:javascript复制{
"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
代码语言:javascript复制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:
代码语言:javascript复制$ 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
代码语言:javascript复制$ 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
代码语言:javascript复制IP_ADDRESS 是控制节点管理网地址
验证ovs
代码语言:javascript复制$ ovs-vsctl add-br br0
$ ovs-vsctl add-port br0 eth0
$ ovs-vsctl add-port br0 vif1.0
$ ovs-vsctl show
启动ovn
代码语言:javascript复制$ /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
代码语言:javascript复制# 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
代码语言:javascript复制配置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
代码语言:javascript复制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
代码语言:javascript复制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
代码语言:javascript复制ovs-vsctl add-br ovs0
使用ovs-docker给容器添加网卡,并挂到ovs0网桥上
代码语言:javascript复制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
代码语言:javascript复制[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
代码语言:javascript复制[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
代码语言:javascript复制[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
代码语言:javascript复制[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 : ""
代码语言:javascript复制设置vlan tag
代码语言:javascript复制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
代码语言:javascript复制测试连通性
代码语言:javascript复制[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
代码语言:javascript复制网桥: ovs0
容器:
con6 192.168.1.2
con7 192.168.1.3
con8 192.168.1.4
代码语言:javascript复制创建方式依上
host2 172.29.101.82
代码语言:javascript复制网桥: ovs1
容器: con11
准备环境
代码语言:javascript复制创建网桥
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
代码语言:javascript复制查看网桥ovs1
代码语言:javascript复制[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
代码语言:javascript复制[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
代码语言:javascript复制[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
代码语言:javascript复制ovs-vsctl set port 0384251973e64_l tag=100
连通性测试
代码语言:javascript复制[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。
代码语言:javascript复制实践
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
代码语言:javascript复制网桥: 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
代码语言:javascript复制[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
代码语言:javascript复制[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
代码语言:javascript复制[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
代码语言:javascript复制[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
代码语言:javascript复制[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:
代码语言:javascript复制[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
代码语言:javascript复制[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:
代码语言:javascript复制[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
代码语言:javascript复制[root@compute82 /]# docker exec -ti con9 bash
root@b55602aad0ac:/#
root@b55602aad0ac:/# ping 192.168.1.2
connect: Network is unreachable
root@b55602aad0ac:/#
代码语言:javascript复制添加流表规则:
在host1上:
代码语言:javascript复制[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
代码语言:javascript复制[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
代码语言:javascript复制[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
代码语言:javascript复制[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
在host1和host2的容器中都添加好路由规则后,测试连通性
代码语言:javascript复制[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
代码语言:javascript复制$ 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
代码语言:javascript复制$ 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:
代码语言:javascript复制$ 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:
代码语言:javascript复制$ 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:
代码语言:javascript复制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 "${PORTNAME}_l"
先创建了一个设备对,然后把设备对一端设置成ovs上的一个interface, 这样容器与ovs就关联上了,再把这个ovs上的port与ovn逻辑子网进行关联即可,请看具体例子:
启动容器后是先要把容器设备对的一端挂在物理交换机上,然后通过设置iface-id来与逻辑交换机进行关联。
代码语言:javascript复制ovs-vsctl --may-exist add-port sw0 port0 -- set interface port0
# 把docker挂到ovs上
ovs-vsctl set Interface port0 external_ids:iface-id=lpor0
# 通过iface-id关联到逻辑端口上
具体代码可以查看这里 这封装了一些基操作
一些具体实现:使用教程
逻辑子网
这里创建四个端口,都挂在ovs br-int网桥上,但是分别属于不同的逻辑交换机,这样不同的逻辑交换机没有连接路由器的情况下是不通的,同一个逻辑子网下端口可以互通。
代码语言:javascript复制ls-create sw0
ls-add-port sw0 sw0-port1 00:00:00:00:00:01 192.168.33.10/24
ls-add-port sw0 sw0-port2 00:00:00:00:00:02 192.168.33.20/24
ls-create sw1
ls-add-port sw1 sw1-port1 00:00:00:00:00:03 192.168.33.30/24
ls-add-port sw1 sw1-port2 00:00:00:00:00:04 192.168.33.40/24
ovs-add-port br-int lport1 sw0-port1 192.168.33.1
ovs-add-port br-int lport2 sw0-port2 192.168.33.1
ovs-add-port br-int lport3 sw1-port1 192.168.33.1
ovs-add-port br-int lport4 sw1-port2 192.168.33.1
ip netns exec lport1-ns ip addr
ip netns exec lport2-ns ip addr
ip netns exec lport3-ns ip addr
ip netns exec lport4-ns ip addr
ip netns exec lport1-ns ping -c3 192.168.33.20
ofport=$(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:
代码语言:javascript复制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
代码语言:javascript复制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比较简单,这里主要讲DHCP实现
DHCP也很简单,主要是给interface设置地址时通过DHCP客户端进行地址配置,其它的同上
代码语言:javascript复制ovs-add-port-dhcp() {
bridge=$1
port=$2
lport=$3
ip netns add $port-ns
ovs-vsctl --may-exist add-port $bridge $port -- set interface $port type=internal
if [ ! -z "$lport" ]; then
ovs-vsctl set Interface $port external_ids:iface-id=$lport
fi
mac=$(ovn-nbctl lsp-get-port-security $lport | head -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 link set $port up
ip netns exec $port-ns dhclient $port # 这里dhclient给interface配置IP地址
}
在逻辑层面因为涉及到IP地址,所以就需要引入逻辑路由器和DHCP配置了
代码语言:javascript复制echo "创建两个逻辑交换机分别有一个端口"
ls-create sw0
ls-add-port sw0 sw0-port1 00:00:00:00:00:01
ls-create sw1
ls-add-port sw1 sw1-port1 00:00:00:00:10:01
# 创建逻辑路由器
ovn-nbctl lr-add lr0
# 给路由器加个网关接口
ovn-nbctl lrp-add lr0 sw0gw 00:00:00:01:00:01 192.168.33.1/24
# 把sw0逻辑交换机挂到sw0gw网关接口上,这里交换机上的端口叫sw0gw-attachment 连接的是sw0gw端口
ovn-nbctl -- lsp-add sw0 sw0gw-attachment
-- set Logical_Switch_Port sw0gw-attachment
type=router
options:router-port=sw0gw
addresses='"00:00:00:01:00:01 192.168.33.1"'
# 同理操作sw1
ovn-nbctl lrp-add lr0 sw1gw 00:00:00:01:00:02 192.168.34.1/24
ovn-nbctl -- lsp-add sw1 sw1gw-attachment
-- set Logical_Switch_Port sw1gw-attachment
type=router
options:router-port=sw1gw
addresses='"00:00:00:01:00:02 192.168.34.1"'
# 设置DHCP配置,这里写死了mac地址与IP地址的映射关系, lease_time是租约时间
sw0DHCP="$(ovn-nbctl create DHCP_Options cidr=192.168.33.10/24
options=""server_id"="192.168.33.10" "server_mac"="00:00:00:00:00:01"
"lease_time"="3600" "router"="192.168.33.1"")"
sw1DHCP="$(ovn-nbctl create DHCP_Options cidr=192.168.34.10/24
options=""server_id"="192.168.34.10" "server_mac"="00:00:00:00:10:01"
"lease_time"="3600" "router"="192.168.34.1"")"
ovn-nbctl dhcp-options-list
# 给逻辑交换机端口设置DHCP规则
ovn-nbctl lsp-set-dhcpv4-options sw0-port1 $sw0DHCP
ovn-nbctl lsp-get-dhcpv4-options sw0-port1
ovn-nbctl lsp-set-dhcpv4-options sw1-port1 $sw1DHCP
ovn-nbctl lsp-get-dhcpv4-options sw1-port1
# 逻辑端口与物理端口绑定并通过DHCP获取地址
ovs-add-port-dhcp br-int lport1 sw0-port1
ovs-add-port-dhcp br-int lport2 sw1-port1
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。