我在 Ubuntu 服务器 20.04 上安装了 Kubernetes。
Master配置了flannel网络没有任何问题。
初始化命令：
kubeadm init --pod-network-cidr=10.10.10.0/24 --apiserver-advertise-address=172.16.200.10
主站上的网络接口：
cni0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1450 [4/651]
inet 10.10.10.1 netmask 255.255.255.0 broadcast 10.10.10.255
inet6 fe80::8e1:9ff:fe5e:56fb prefixlen 64 scopeid 0x20<link>
ether be:cc:5a:4b:f0:c0 txqueuelen 1000 (Ethernet)
RX packets 6565 bytes 400726 (400.7 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 3121 bytes 291909 (291.9 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
docker0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
inet 172.17.0.1 netmask 255.255.0.0 broadcast 172.17.255.255
ether 02:42:9e:d3:e7:73 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 1500
inet 172.16.200.10 netmask 255.255.255.0 broadcast 172.16.200.255
inet6 fe80::20c:29ff:fe6b:dbf8 prefixlen 64 scopeid 0x20<link>
ether 00:0c:29:6b:db:f8 txqueuelen 1000 (Ethernet)
RX packets 7134 bytes 713894 (713.8 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 9077 bytes 2726670 (2.7 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
flannel.1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1450
inet 10.10.10.0 netmask 255.255.255.255 broadcast 10.10.10.0
inet6 fe80::ec9f:dfff:fe19:b2bd prefixlen 64 scopeid 0x20<link>
ether ee:9f:df:19:b2:bd 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 14 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 222414 bytes 41222254 (41.2 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 222414 bytes 41222254 (41.2 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
veth92c2b55e: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1450
inet6 fe80::bccc:5aff:fe4b:f0c0 prefixlen 64 scopeid 0x20<link>
ether be:cc:5a:4b:f0:c0 txqueuelen 0 (Ethernet)
RX packets 3252 bytes 244283 (244.2 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 1602 bytes 148781 (148.7 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
vethdc37182b: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1450
inet6 fe80::d84e:c0ff:feda:9875 prefixlen 64 scopeid 0x20<link>
ether da:4e:c0:da:98:75 txqueuelen 0 (Ethernet)
RX packets 3313 bytes 248353 (248.3 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 1540 bytes 144798 (144.7 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
/var/log/syslog但节点在加入集群后会导致此错误。
Jan 27 08:08:33 k8s-node1 kubelet[5393]: E0127 08:08:33.534423 5393 pod_workers.go:191] Error syncing pod 90b895af-b046-4149-ac18-bbec859c37a2 ("kube-flannel-ds-vsgx8_kube-system(90b895af-b046-4149-ac18-bbec859c37a2)"), skipping: failed to "StartContainer" for "kube-flannel" with CrashLoopBackOff: "back-off 2m40s restarting failed container=kube-flannel pod=kube-flannel-ds-vsgx8_kube-system(90b895af-b046-4149-ac18-bbec859c37a2)"
这是节点状态：
root@k8s-master:~# kubectl get node -o wide
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
k8s-master Ready control-plane,master 42m v1.20.2 172.16.200.10 <none> Ubuntu 20.04.1 LTS 5.4.0-62-generic docker://19.3.8
k8s-node1 Ready <none> 35m v1.20.2 172.16.200.20 <none> Ubuntu 20.04.1 LTS 5.4.0-62-generic docker://19.3.8
这是什么错误？
如何解决这个问题？
更新
这是 Node1 中存在的容器：
root@k8s-node1:~# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
358f8cdc6141 f03a23d55e57 "/opt/bin/flanneld -…" 15 seconds ago Exited (1) 12 seconds ago k8s_kube-flannel_kube-flannel-ds-vsgx8_kube-system_90b895af-b046-4149-ac18-bbec859c37a2_7
e3a40bcc9db3 f03a23d55e57 "cp -f /etc/kube-fla…" 11 minutes ago Exited (0) 11 minutes ago k8s_install-cni_kube-flannel-ds-vsgx8_kube-system_90b895af-b046-4149-ac18-bbec859c37a2_0
7ccb8514bed7 43154ddb57a8 "/usr/local/bin/kube…" 11 minutes ago Up 11 minutes k8s_kube-proxy_kube-proxy-mvbw2_kube-system_5090f36a-4178-4318-aa15-19c61239045f_0
27ae4b2a1157 k8s.gcr.io/pause:3.2 "/pause" 11 minutes ago Up 11 minutes k8s_POD_kube-flannel-ds-vsgx8_kube-system_90b895af-b046-4149-ac18-bbec859c37a2_0
507f2d4ab72c k8s.gcr.io/pause:3.2 "/pause" 11 minutes ago Up 11 minutes k8s_POD_kube-proxy-mvbw2_kube-system_5090f36a-4178-4318-aa15-19c61239045f_0
容器错误：
root@k8s-node1:~# docker logs k8s_kube-flannel_kube-flannel-ds-vsgx8_kube-system_90b895af-b046-4149-ac18-bbec859c37a2_7
ERROR: logging before flag.Parse: I0127 08:16:06.400204 1 main.go:519] Determining IP address of default interface
ERROR: logging before flag.Parse: I0127 08:16:06.402530 1 main.go:532] Using interface with name eth0 and address 172.16.200.20
ERROR: logging before flag.Parse: I0127 08:16:06.402721 1 main.go:549] Defaulting external address to interface address (172.16.200.20)
W0127 08:16:06.402840 1 client_config.go:608] Neither --kubeconfig nor --master was specified. Using the inClusterConfig. This might not work.
ERROR: logging before flag.Parse: I0127 08:16:07.100353 1 kube.go:116] Waiting 10m0s for node controller to sync
ERROR: logging before flag.Parse: I0127 08:16:07.100618 1 kube.go:299] Starting kube subnet manager
ERROR: logging before flag.Parse: I0127 08:16:08.101341 1 kube.go:123] Node controller sync successful
ERROR: logging before flag.Parse: I0127 08:16:08.101408 1 main.go:253] Created subnet manager: Kubernetes Subnet Manager - k8s-node1
ERROR: logging before flag.Parse: I0127 08:16:08.101423 1 main.go:256] Installing signal handlers
ERROR: logging before flag.Parse: I0127 08:16:08.102395 1 main.go:391] Found network config - Backend type: vxlan
ERROR: logging before flag.Parse: I0127 08:16:08.103389 1 vxlan.go:123] VXLAN config: VNI=1 Port=0 GBP=false Learning=false DirectRouting=false
ERROR: logging before flag.Parse: E0127 08:16:08.104363 1 main.go:292] Error registering network: failed to acquire lease: node "k8s-node1" pod cidr not assigned
ERROR: logging before flag.Parse: I0127 08:16:08.105069 1 main.go:371] Stopping shutdownHandler...
为什么在节点中，法兰绒容器退出了？！！！
答案1
这--pod-network-cidr 10.10.10.0/24听起来不对。
如果你做 a kubectl describe node <your-master-node-name>，我敢打赌会有类似 a 的东西PodCIDR: 10.10.10.0/24。您的第一个节点已经占用了整个 Pod 网络 CIDR，因为您计划的节点太小了。
一旦 flannel 首次在 Kubernetes 节点上启动，它就会为自己分配一个 /24 子网，在 pod 网络范围内。我假设您的第二个节点没有 IP 来加入 SDN。