尽管 PodCIDR 在节点上可用,但 Kube-Flannel 无法获得 CIDR

Kube-Flannel cant get CIDR although PodCIDR available on node

目前我正在 1 主 2 节点环境中设置 Kubernetes。

我成功初始化Master并将节点添加到Cluster

kubectl get nodes

当我将节点加入集群时,kube-proxy pod 成功启动,但 kube-flannel pod 出错并遇到 CrashLoopBackOff。

绒布-pod.log:

I0613 09:03:36.820387       1 main.go:475] Determining IP address of default interface,
I0613 09:03:36.821180       1 main.go:488] Using interface with name ens160 and address 172.17.11.2,
I0613 09:03:36.821233       1 main.go:505] Defaulting external address to interface address (172.17.11.2),
I0613 09:03:37.015163       1 kube.go:131] Waiting 10m0s for node controller to sync,
I0613 09:03:37.015436       1 kube.go:294] Starting kube subnet manager,
I0613 09:03:38.015675       1 kube.go:138] Node controller sync successful,
I0613 09:03:38.015767       1 main.go:235] Created subnet manager: Kubernetes Subnet Manager - caasfaasslave1.XXXXXX.local,
I0613 09:03:38.015828       1 main.go:238] Installing signal handlers,
I0613 09:03:38.016109       1 main.go:353] Found network config - Backend type: vxlan,
I0613 09:03:38.016281       1 vxlan.go:120] VXLAN config: VNI=1 Port=0 GBP=false DirectRouting=false,
E0613 09:03:38.016872       1 main.go:280] Error registering network: failed to acquire lease: node "caasfaasslave1.XXXXXX.local" pod cidr not assigned,
I0613 09:03:38.016966       1 main.go:333] Stopping shutdownHandler...,

在节点上,我可以验证 PodCDIR 是否可用:

kubectl get nodes -o jsonpath='{.items[*].spec.podCIDR}'
172.17.12.0/24

Masters kube-controller-manager上,pod cidr也有

[root@caasfaasmaster manifests]# cat kube-controller-manager.yaml
apiVersion: v1
kind: Pod
metadata:
  annotations:
    scheduler.alpha.kubernetes.io/critical-pod: ""
  creationTimestamp: null
  labels:
    component: kube-controller-manager
    tier: control-plane
  name: kube-controller-manager
  namespace: kube-system
spec:
  containers:
  - command:
    - kube-controller-manager
    - --leader-elect=true
    - --controllers=*,bootstrapsigner,tokencleaner
    - --cluster-signing-key-file=/etc/kubernetes/pki/ca.key
    - --address=127.0.0.1
    - --use-service-account-credentials=true
    - --kubeconfig=/etc/kubernetes/controller-manager.conf
    - --root-ca-file=/etc/kubernetes/pki/ca.crt
    - --service-account-private-key-file=/etc/kubernetes/pki/sa.key
    - --cluster-signing-cert-file=/etc/kubernetes/pki/ca.crt
    - --allocate-node-cidrs=true
    - --cluster-cidr=172.17.12.0/24
    - --node-cidr-mask-size=24
    env:
    - name: http_proxy
      value: http://ntlmproxy.XXXXXX.local:3154
    - name: https_proxy
      value: http://ntlmproxy.XXXXXX.local:3154
    - name: no_proxy
      value: .XXXXX.local,172.17.11.0/24,172.17.12.0/24
    image: k8s.gcr.io/kube-controller-manager-amd64:v1.10.4
    livenessProbe:
      failureThreshold: 8
      httpGet:
        host: 127.0.0.1
        path: /healthz
        port: 10252
        scheme: HTTP
      initialDelaySeconds: 15
      timeoutSeconds: 15
    name: kube-controller-manager
    resources:
      requests:
        cpu: 200m
    volumeMounts:
    - mountPath: /etc/kubernetes/pki
      name: k8s-certs
      readOnly: true
    - mountPath: /etc/ssl/certs
      name: ca-certs
      readOnly: true
    - mountPath: /etc/kubernetes/controller-manager.conf
      name: kubeconfig
      readOnly: true
    - mountPath: /etc/pki
      name: ca-certs-etc-pki
      readOnly: true
  hostNetwork: true
  volumes:
  - hostPath:
      path: /etc/pki
      type: DirectoryOrCreate
    name: ca-certs-etc-pki
  - hostPath:
      path: /etc/kubernetes/pki
      type: DirectoryOrCreate
    name: k8s-certs
  - hostPath:
      path: /etc/ssl/certs
      type: DirectoryOrCreate
    name: ca-certs
  - hostPath:
      path: /etc/kubernetes/controller-manager.conf
      type: FileOrCreate
    name: kubeconfig
status: {}

XXXXX 用于匿名化

我用下面的 kubeadm 命令初始化了 master(也没有任何错误)

kubeadm init --pod-network-cidr=172.17.12.0/24 --service- 
cidr=172.17.11.129/25 --service-dns-domain=dcs.XXXXX.local

有谁知道是什么导致了我的问题以及如何解决这些问题?

NAMESPACE     NAME                                                  READY     STATUS             RESTARTS   AGE       IP            NODE
kube-system   etcd-caasfaasmaster.XXXXXX.local                      1/1       Running            0          16h       172.17.11.1   caasfaasmaster.XXXXXX.local
kube-system   kube-apiserver-caasfaasmaster.XXXXXX.local            1/1       Running            1          16h       172.17.11.1   caasfaasmaster.XXXXXX.local
kube-system   kube-controller-manager-caasfaasmaster.XXXXXX.local   1/1       Running            0          16h       172.17.11.1   caasfaasmaster.XXXXXX.local
kube-system   kube-dns-75c5968bf9-qfh96                             3/3       Running            0          16h       172.17.12.2   caasfaasmaster.XXXXXX.local
kube-system   kube-flannel-ds-4b6kf                                 0/1       CrashLoopBackOff   205        16h       172.17.11.2   caasfaasslave1.XXXXXX.local
kube-system   kube-flannel-ds-j2fz6                                 0/1       CrashLoopBackOff   191        16h       172.17.11.3   caasfassslave2.XXXXXX.local
kube-system   kube-flannel-ds-qjd89                                 1/1       Running            0          16h       172.17.11.1   caasfaasmaster.XXXXXX.local
kube-system   kube-proxy-h4z54                                      1/1       Running            0          16h       172.17.11.3   caasfassslave2.XXXXXX.local
kube-system   kube-proxy-sjwl2                                      1/1       Running            0          16h       172.17.11.2   caasfaasslave1.XXXXXX.local
kube-system   kube-proxy-zc5xh                                      1/1       Running            0          16h       172.17.11.1   caasfaasmaster.XXXXXX.local
kube-system   kube-scheduler-caasfaasmaster.XXXXXX.local            1/1       Running            0          16h       172.17.11.1   caasfaasmaster.XXXXXX.local

根据法兰绒 documentation:

At the bare minimum, you must tell flannel an IP range (subnet) that it should use for the overlay. Here is an example of the minimum flannel configuration:

{ "Network": "10.1.0.0/16" }

因此,您需要为pods指定一个最小尺寸为/16的网络,并且它不应该是您现有网络的一部分,因为Flannel使用封装来连接pods 在不同的节点上到一个覆盖网络。

这是描述它的文档部分:

With Docker, each container is assigned an IP address that can be used to communicate with other containers on the same host. For communicating over a network, containers are tied to the IP addresses of the host machines and must rely on port-mapping to reach the desired container. This makes it difficult for applications running inside containers to advertise their external IP and port as that information is not available to them.

flannel solves the problem by giving each container an IP that can be used for container-to-container communication. It uses packet encapsulation to create a virtual overlay network that spans the whole cluster. More specifically, flannel gives each host an IP subnet (/24 by default) from which the Docker daemon is able to allocate IPs to the individual containers.

换句话说,您应该使用如下设置重新创建集群:

kubeadm init --pod-network-cidr=10.17.0.0/16 --service-cidr=10.18.0.0/24 --service-dns-domain=dcs.XXXXX.local

Failed to acquire lease 简单的意思是,pod 没有得到 podCIDR。尽管主节点上的清单显示 podCIDR 为真,但我也遇到过这种情况,但它仍然无法正常工作并且漏斗进入崩溃回环。 这就是我修复它的方法。

从主节点,首先找出你的漏斗CIDR

sudo cat /etc/kubernetes/manifests/kube-controller-manager.yaml | grep -i cluster-cidr

输出:

- --cluster-cidr=172.168.10.0/24

然后运行来自主节点的以下内容:

kubectl patch node slave-node-1 -p '{"spec":{"podCIDR":"172.168.10.0/24"}}'

其中, slave-node-1 是获取租约失败的节点 podCIDR 是你在上一个命令中找到的 cidr

希望这对您有所帮助。