最近在玩Google Kubernetes Engine叢集。我有一個關於他們的 CNI 的問題。我從 GCP 文件和其他文章中讀到，有一個所有 veth 介面都連接到的橋接器。基本上，對於每個容器，都會建立一個 veth 對。它的一端位於容器內，另一端連接至橋接裝置。當同一節點上的容器相互通訊時，封包交換使用二層橋接設備。 GKE 文件也是這樣描述的。
https://cloud.google.com/kubernetes-engine/docs/concepts/network-overview#pods
https://medium.com/cloudzone/gke-networking-options-explained-demonstrated-5c0253415eba
我在Google上創建了一個集群，我可以看到有一個橋接設備docker0，但沒有與之關聯的介面。
gke-xxxxxxxxx /home/uuuuuuu # brctl show
bridge name bridge id STP enabled interfaces
docker0 8000.0242fd0b0cf4 no
gke-xxxxxxxxxx /home/uuuuuuu #
然後我使用 Virtualbox 建立了一個集群，我可以看到介面與橋接設備關聯。
[root@k8s-2 ~]# brctl show
bridge name bridge id STP enabled interfaces
cni0 8000.36dae477639c no veth7f6c1f01
vethccd0d71d
vethe63e4285
我想推理的是為什麼我在 Google VM 上找不到橋接設備？在這種情況下使用的 Linux 核心有什麼特殊功能嗎？
當我檢查 Google VM 上的每個 veth 介面時，它們都有相同的 IP 位址 10.188.2.1
gke-xxxxxxxxxxxxxxxxxxxxx /home/user.name # ifconfig
docker0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
inet 169.254.123.1 netmask 255.255.255.0 broadcast 169.254.123.255
ether 02:42:fd:0b:0c:f4 txqueuelen 0 (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
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1460
inet 10.10.1.19 netmask 255.255.255.255 broadcast 0.0.0.0
inet6 fe80::4001:aff:fe0a:113 prefixlen 64 scopeid 0x20<link>
ether 42:01:0a:0a:01:13 txqueuelen 1000 (Ethernet)
RX packets 2192921 bytes 1682211226 (1.5 GiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 1288701 bytes 468627202 (446.9 MiB)
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 276348 bytes 153128345 (146.0 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 276348 bytes 153128345 (146.0 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
veth27cee774: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1460
inet 10.188.2.1 netmask 255.255.255.255 broadcast 10.188.2.1
inet6 fe80::10b7:98ff:fe2f:2e08 prefixlen 64 scopeid 0x20<link>
ether 12:b7:98:2f:2e:08 txqueuelen 0 (Ethernet)
RX packets 32 bytes 2306 (2.2 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 10 bytes 710 (710.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
veth6eba4cdf: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1460
inet 10.188.2.1 netmask 255.255.255.255 broadcast 10.188.2.1
inet6 fe80::c4e3:b0ff:fe5f:63da prefixlen 64 scopeid 0x20<link>
ether c6:e3:b0:5f:63:da txqueuelen 0 (Ethernet)
RX packets 537091 bytes 138245354 (131.8 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 477870 bytes 122515885 (116.8 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
veth8bcf1494: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1460
inet 10.188.2.1 netmask 255.255.255.255 broadcast 10.188.2.1
inet6 fe80::70cb:c4ff:fe8c:a747 prefixlen 64 scopeid 0x20<link>
ether 72:cb:c4:8c:a7:47 txqueuelen 0 (Ethernet)
RX packets 50 bytes 3455 (3.3 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 28 bytes 2842 (2.7 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
vethbb2135c7: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1460
inet 10.188.2.1 netmask 255.255.255.255 broadcast 10.188.2.1
inet6 fe80::1469:daff:fea0:8b5b prefixlen 64 scopeid 0x20<link>
ether 16:69:da:a0:8b:5b txqueuelen 0 (Ethernet)
RX packets 223995 bytes 82725559 (78.8 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 239258 bytes 60203574 (57.4 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
vetheee4e8e3: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1460
inet 10.188.2.1 netmask 255.255.255.255 broadcast 10.188.2.1
inet6 fe80::ec6c:3bff:fef3:70c2 prefixlen 64 scopeid 0x20<link>
ether ee:6c:3b:f3:70:c2 txqueuelen 0 (Ethernet)
RX packets 311669 bytes 40562747 (38.6 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 304461 bytes 628195110 (599.0 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
這些 veth 介面背後是什麼？
先致謝
答案1
如果網橋已經有接口，則brctl show可以使用該命令查看節點的網橋和接口詳細資訊。看來您還沒有在您的情況下向橋引入任何接口。您可以使用 向網橋添加接口sudo brctl addif docker0 veth0，並且可以使用相同的命令在節點中接收所有重要的網橋和接口詳細資訊。查看這個文件以供參考。