flannel crashloopbackoff problem

[msuluhan]

Hello

I am new in K8S and trying to build cluster with one worker and one master on Ubuntu 20.04.4 LTS release

root@k8smaster1:~# kubeadm version
kubeadm version: &version.Info{Major:"1", Minor:"24", GitVersion:"v1.24.1", GitCommit:"3ddd0f45aa91e2f30c70734b175631bec5b5825a", GitTreeState:"clean", BuildDate:"2022-05-24T12:24:38Z", GoVersion:"go1.18.2", Compiler:"gc", Platform:"linux/amd64"}
root@k8smaster1:~# kubectl version
WARNING: This version information is deprecated and will be replaced with the output from kubectl version --short.  Use --output=yaml|json to get the full version.
Client Version: version.Info{Major:"1", Minor:"24", GitVersion:"v1.24.1", GitCommit:"3ddd0f45aa91e2f30c70734b175631bec5b5825a", GitTreeState:"clean", BuildDate:"2022-05-24T12:26:19Z", GoVersion:"go1.18.2", Compiler:"gc", Platform:"linux/amd64"}
Kustomize Version: v4.5.4
Server Version: version.Info{Major:"1", Minor:"24", GitVersion:"v1.24.1", GitCommit:"3ddd0f45aa91e2f30c70734b175631bec5b5825a", GitTreeState:"clean", BuildDate:"2022-05-24T12:18:48Z", GoVersion:"go1.18.2", Compiler:"gc", Platform:"linux/amd64"}
root@k8smaster1:~# 

My problem is flannel pod is not starting as I expected

root@k8smaster1:~# kubectl get pods --all-namespaces
NAMESPACE     NAME                                 READY   STATUS             RESTARTS         AGE
kube-system   coredns-6d4b75cb6d-7mqzw             0/1     Pending            0                5d19h
kube-system   coredns-6d4b75cb6d-ph8rq             0/1     Pending            0                5d19h
kube-system   etcd-k8smaster1                      1/1     Running            1                5d19h
kube-system   kube-apiserver-k8smaster1            1/1     Running            1                5d19h
kube-system   kube-controller-manager              0/1     Pending            0                5d19h
kube-system   kube-controller-manager-k8smaster1   1/1     Running            1 (38m ago)      5d19h
kube-system   kube-flannel-ds-smrl5                0/1     CrashLoopBackOff   1630 (57s ago)   5d19h
kube-system   kube-proxy-f5zmv                     1/1     Running            0                5d19h
kube-system   kube-scheduler-k8smaster1            1/1     Running            2 (38m ago)      5d19h

root@k8smaster1:~# kubectl logs -n kube-system kube-flannel-ds-smrl5
Defaulted container "kube-flannel" out of: kube-flannel, install-cni-plugin (init), install-cni (init)
I0602 08:50:37.159592       1 main.go:207] CLI flags config: {etcdEndpoints:http://127.0.0.1:4001,http://127.0.0.1:2379 etcdPrefix:/coreos.com/network etcdKeyfile: etcdCertfile: etcdCAFile: etcdUsername: etcdPassword: version:false kubeSubnetMgr:true kubeApiUrl: kubeAnnotationPrefix:flannel.alpha.coreos.com kubeConfigFile: iface:[] ifaceRegex:[] ipMasq:true ifaceCanReach: subnetFile:/run/flannel/subnet.env publicIP: publicIPv6: subnetLeaseRenewMargin:60 healthzIP:0.0.0.0 healthzPort:0 iptablesResyncSeconds:5 iptablesForwardRules:true netConfPath:/etc/kube-flannel/net-conf.json setNodeNetworkUnavailable:true}
W0602 08:50:37.159936       1 client_config.go:614] Neither --kubeconfig nor --master was specified.  Using the inClusterConfig.  This might not work.
I0602 08:50:37.256808       1 kube.go:121] Waiting 10m0s for node controller to sync
I0602 08:50:37.257106       1 kube.go:398] Starting kube subnet manager
I0602 08:50:38.257175       1 kube.go:128] Node controller sync successful
I0602 08:50:38.257195       1 main.go:227] Created subnet manager: Kubernetes Subnet Manager - k8smaster1
I0602 08:50:38.257198       1 main.go:230] Installing signal handlers
I0602 08:50:38.257366       1 main.go:463] Found network config - Backend type: vxlan
I0602 08:50:38.257411       1 match.go:195] Determining IP address of default interface
I0602 08:50:38.257832       1 match.go:248] Using interface with name ens160 and address 172.30.99.230
I0602 08:50:38.257881       1 match.go:270] Defaulting external address to interface address (172.30.99.230)
I0602 08:50:38.257990       1 vxlan.go:138] VXLAN config: VNI=1 Port=0 GBP=false Learning=false DirectRouting=false
E0602 08:50:38.258282       1 main.go:326] Error registering network: failed to acquire lease: node "k8smaster1" pod cidr not assigned
I0602 08:50:38.258417       1 main.go:443] Stopping shutdownHandler...

root@k8smaster1:~# ps -ef | grep cluster-cidr
root      485652   73904  0 08:12 ?        00:00:13 kube-controller-manager --allocate-node-cidrs=true --authentication-kubeconfig=/etc/kubernetes/controller-manager.conf --authorization-kubeconfig=/etc/kubernetes/controller-manager.conf --bind-address=127.0.0.1 --client-ca-file=/etc/kubernetes/pki/ca.crt --cluster-cidr=10.100.0.0/24 --cluster-name=kubernetes --cluster-signing-cert-file=/etc/kubernetes/pki/ca.crt --cluster-signing-key-file=/etc/kubernetes/pki/ca.key --controllers=*,bootstrapsigner,tokencleaner --kubeconfig=/etc/kubernetes/controller-manager.conf --leader-elect=true --requestheader-client-ca-file=/etc/kubernetes/pki/front-proxy-ca.crt --root-ca-file=/etc/kubernetes/pki/ca.crt --service-account-private-key-file=/etc/kubernetes/pki/sa.key --service-cluster-ip-range=10.96.0.0/12 --use-service-account-credentials=true
root      488019  487554  0 08:52 pts/0    00:00:00 grep --color=auto cluster-cidr

kube-controller-manager.yml file as follows

root@k8smaster1:/etc/kubernetes/manifests# more kube-controller-manager.yaml 
apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  labels:
    component: kube-controller-manager
    tier: control-plane
  name: kube-controller-manager
  namespace: kube-system
spec:
  containers:
  - command:
    - kube-controller-manager
    - --allocate-node-cidrs=true
    - --authentication-kubeconfig=/etc/kubernetes/controller-manager.conf
    - --authorization-kubeconfig=/etc/kubernetes/controller-manager.conf
    - --bind-address=127.0.0.1
    - --client-ca-file=/etc/kubernetes/pki/ca.crt
    - --cluster-cidr=10.100.0.0/24
    - --cluster-name=kubernetes
    - --cluster-signing-cert-file=/etc/kubernetes/pki/ca.crt
    - --cluster-signing-key-file=/etc/kubernetes/pki/ca.key
    - --controllers=*,bootstrapsigner,tokencleaner
    - --kubeconfig=/etc/kubernetes/controller-manager.conf
    - --leader-elect=true
    - --requestheader-client-ca-file=/etc/kubernetes/pki/front-proxy-ca.crt
    - --root-ca-file=/etc/kubernetes/pki/ca.crt
    - --service-account-private-key-file=/etc/kubernetes/pki/sa.key
    - --service-cluster-ip-range=10.96.0.0/12
    - --use-service-account-credentials=true
    image: k8s.gcr.io/kube-controller-manager:v1.24.1
    imagePullPolicy: IfNotPresent
    livenessProbe:
      failureThreshold: 8
      httpGet:
        host: 127.0.0.1
        path: /healthz
        port: 10257
        scheme: HTTPS
      initialDelaySeconds: 10
      periodSeconds: 10
      timeoutSeconds: 15
    name: kube-controller-manager
    resources:
      requests:
        cpu: 200m
    startupProbe:
      failureThreshold: 24
      httpGet:
        host: 127.0.0.1
        path: /healthz
        port: 10257
        scheme: HTTPS
      initialDelaySeconds: 10
      periodSeconds: 10
      timeoutSeconds: 15
    volumeMounts:
    - mountPath: /etc/ssl/certs
      name: ca-certs
      readOnly: true
    - mountPath: /etc/ca-certificates
      name: etc-ca-certificates
      readOnly: true
    - mountPath: /etc/pki
      name: etc-pki
      readOnly: true
    - mountPath: /usr/libexec/kubernetes/kubelet-plugins/volume/exec
      name: flexvolume-dir
    - mountPath: /etc/kubernetes/pki
      name: k8s-certs
      readOnly: true
    - mountPath: /etc/kubernetes/controller-manager.conf
      name: kubeconfig
      readOnly: true
    - mountPath: /usr/local/share/ca-certificates
      name: usr-local-share-ca-certificates
      readOnly: true
    - mountPath: /usr/share/ca-certificates
      name: usr-share-ca-certificates
      readOnly: true
  hostNetwork: true
  priorityClassName: system-node-critical
  securityContext:
    seccompProfile:
      type: RuntimeDefault
  volumes:
  - hostPath:
      path: /etc/ssl/certs
      type: DirectoryOrCreate
    name: ca-certs
  - hostPath:
      path: /etc/ca-certificates
      type: DirectoryOrCreate
    name: etc-ca-certificates
  - hostPath:
      path: /etc/pki
      type: DirectoryOrCreate
    name: etc-pki
  - hostPath:
      path: /usr/libexec/kubernetes/kubelet-plugins/volume/exec
      type: DirectoryOrCreate
    name: flexvolume-dir
  - hostPath:
      path: /etc/kubernetes/pki
      type: DirectoryOrCreate
    name: k8s-certs
  - hostPath:
      path: /etc/kubernetes/controller-manager.conf
      type: FileOrCreate
    name: kubeconfig
  - hostPath:
      path: /usr/local/share/ca-certificates
      type: DirectoryOrCreate
    name: usr-local-share-ca-certificates
  - hostPath:
      path: /usr/share/ca-certificates
      type: DirectoryOrCreate
    name: usr-share-ca-certificates
status: {}

I think I am missing something but could not figured out yet

Could you help me to fix flannel issue ?

[manuelbuil]

How did you install flannel?

[Pilipana]

How did you install flannel?

v0.18.0 not working with error that can not find local interface. you can try to modify to previous version

[stale[bot]]

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