目錄
- 一. 環境介紹
- 二. docker跨主機互聯實現說明
- 三. 修改docker0網橋網段
- 3.1 A宿主機10.1.10.113
- 3.2 B宿主機10.1.10.114
背景：最近閑來無事，想到之前開發提出的問題不用k8s那套網絡插件如何實現跨宿主機的容器之間網絡互聯，順便復習下iptables知識點。
docker實現跨宿主機的容器之間網絡互聯 一. 環境介紹二. docker跨主機互聯實現說明三. 修改docker0網橋網段3.1 A宿主機10.1.10.1133.2 B宿主機10.1.10.114
一. 環境介紹
兩臺centos8.2的虛擬機以及harbor倉庫的鏡像
宿主機A：ip 10.1.10.113
宿主機B：ip 10.1.10.114
二. docker跨主機互聯實現說明
跨主機互聯是說A宿主機的容器可以訪問B主機上的容器，但是前提是保證各宿主機之間的網絡是可以相互通信的，然后各容器才可以通過宿主機訪問到對方的容器。
實現原理: 是在宿主機做一個網絡路由就可以實現A宿主機的容器訪問B主機的容器的目的
三. 修改docker0網橋網段
3.1 A宿主機10.1.10.113
設置docker網橋網段為192.168.100.1
systemctl restart docker docker login 10.1.10.15 docker pull 10.1.10.15/syimage/centos8.2:v2 docker run -itd --restart=always --name=vm01 --privileged 10.1.10.15/syimage/centos8.2:v2
添加靜態路由和iptables規則
在各宿主機添加靜態路由，網關指向對方宿主機的IP
route add -net 192.168.200.0/24 gw 10.1.10.114 iptables -A FORWARD -s 10.0.0.0/24 -j ACCEPT #或者修改FORWARD默認規則 iptables -P FORWARD ACCEPT route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 10.1.10.1 0.0.0.0 UG 100 0 0 ens32 10.1.10.0 0.0.0.0 255.255.255.0 U 100 0 0 ens32 192.168.100.0 0.0.0.0 255.255.255.0 U 0 0 0 docker0 192.168.200.0 10.1.10.114 255.255.255.0 UG 0 0 0 ens32
測試跨宿主機之間容器互聯
docker exec -it vm01 ifconfig
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.100.2 netmask 255.255.255.0 broadcast 192.168.100.255
ether 02:42:c0:a8:64:02 txqueuelen 0 (Ethernet)
RX packets 36 bytes 25292 (24.6 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 45 bytes 5310 (5.1 KiB)
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
loop txqueuelen 1000 (Local Loopback)
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
[root@shudun ~]# docker exec -it vm01 ping 192.168.200.2
PING 192.168.200.2 (192.168.200.2) 56(84) bytes of data.
64 bytes from 192.168.200.2: icmp_seq=1 ttl=62 time=0.907 ms
64 bytes from 192.168.200.2: icmp_seq=2 ttl=62 time=0.678 ms
^C
--- 192.168.200.2 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 2ms
rtt min/avg/max/mdev = 0.678/0.792/0.907/0.117 ms
3.2 B宿主機10.1.10.114
設置docker網橋網段為192.168.200.1
systemctl restart docker route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 10.1.10.1 0.0.0.0 UG 100 0 0 ens32 10.1.10.0 0.0.0.0 255.255.255.0 U 100 0 0 ens32 192.168.100.0 10.1.10.113 255.255.255.0 UG 0 0 0 ens32 192.168.200.0 0.0.0.0 255.255.255.0 U 0 0 0 docker0 docker login 10.1.10.15 docker pull 10.1.10.15/syimage/centos8.2:v2 docker run -itd --restart=always --name=vm01 --privileged 10.1.10.15/syimage/centos8.2:v2
添加靜態路由和iptables規則
在各宿主機添加靜態路由，網關指向對方宿主機的IP
route add -net 192.168.100.0/24 gw 10.1.10.113 iptables -A FORWARD -s 10.0.0.0/24 -j ACCEPT #或者修改FORWARD默認規則 iptables -P FORWARD ACCEPT route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 10.1.10.1 0.0.0.0 UG 100 0 0 ens32 10.1.10.0 0.0.0.0 255.255.255.0 U 100 0 0 ens32 192.168.100.0 10.1.10.113 255.255.255.0 UG 0 0 0 ens32 192.168.200.0 0.0.0.0 255.255.255.0 U 0 0 0 docker0
測試跨宿主機之間容器互聯
docker exec -it vm01 ifconfig
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.200.2 netmask 255.255.255.0 broadcast 192.168.200.255
ether 02:42:c0:a8:c8:02 txqueuelen 0 (Ethernet)
RX packets 36 bytes 25280 (24.6 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 45 bytes 5322 (5.1 KiB)
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
loop txqueuelen 1000 (Local Loopback)
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
[root@shudun ~]# docker exec -it vm01 ping 192.168.100.2
PING 192.168.100.2 (192.168.100.2) 56(84) bytes of data.
64 bytes from 192.168.100.2: icmp_seq=1 ttl=62 time=0.704 ms
64 bytes from 192.168.100.2: icmp_seq=2 ttl=62 time=0.650 ms
^C
--- 192.168.100.2 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 51ms
rtt min/avg/max/mdev = 0.650/0.677/0.704/0.027 ms
最后宿主機A的容器vm01訪問宿主機B容器vm02，同時在宿主機B上tcpdump抓包觀察
