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kuberneteskubeadm

kubeadm init --apiserver-advertise-address flag equivalent in config file


I need to initialize my kubernetes cluster using a kubeadm config file due to some extra arguments that I need to pass, which are not directly available to kubeadm init.

I did create a config file and it works fine. I went throgh the documentation of the kubeadm config file but still not able to get which option is equivalent to the command line flag --apiserver-advertise-address

My kubeadm version is 1.15.7

This is my current config: Commented out lines are the options which I already tried but dosen't seem to work.

#apiVersion: kubeadm.k8s.io/v1beta2
#kind: InitConfiguration
#APIEndpoint:
#  advertiseAddress: "192.168.224.22"
#  bindPort: 6443
#controlPlaneEndpoint: "192.168.224.22:6443"
apiServer:
  advertiseAddress: "192.168.224.22"
  extraArgs:
    authorization-mode: Node,RBAC
#    advertise-address: 192.168.224.22
    authentication-token-webhook-config-file: /webhook/webhook-config.yaml
  extraVolumes:
  - name: "webhook-conf"
    hostPath: "/webhook/"
    mountPath: "/webhook/"
    readOnly: true
    pathType: DirectoryOrCreate
  timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta2
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controllerManager: {}
dns:
  type: CoreDNS
etcd:
  local:
    dataDir: /var/lib/etcd
#APIEndpoint:
#  advertiseAddress: "192.168.224.22"
#  bindPort: 6443
imageRepository: k8s.gcr.io
kind: ClusterConfiguration
kubernetesVersion: v1.15.10
networking:
#  advertiseAddress: "192.168.224.22"
  dnsDomain: cluster.local
  podSubnet: 10.244.0.0/16
  serviceSubnet: 10.96.0.0/12
scheduler: {}

This is what I'm trying to configure.


Solution

  • To specify the --apiserver-advertise-address flag in the kubeadm config file use this in the init configuration:

    localAPIEndpoint:
      advertiseAddress: 192.168.224.22
      bindPort: 6443
    

    Initially when I was using this the address changed but then the worker nodes were not able to join the cluster due to a CRI socket misconfiguration.

    Turns out using kubeadm config view doesn't print out the entire configuration that was used during cluster creation. The kind: InitConfiguration is skipped, due to which the misconfiguration occured.

    Use kubeadm config print init-defaults to get the init block of the config file. Then it should work.

    Final working config file:

    apiVersion: kubeadm.k8s.io/v1beta2
    bootstrapTokens:
    - groups:
      - system:bootstrappers:kubeadm:default-node-token
      token: abcdef.0123456789abcdef
      ttl: 24h0m0s
      usages:
      - signing
      - authentication
    kind: InitConfiguration
    localAPIEndpoint:
      advertiseAddress: 192.168.224.22
      bindPort: 6443
    nodeRegistration:
      criSocket: /var/run/dockershim.sock
      name: hostname1
      taints:
      - effect: NoSchedule
        key: node-role.kubernetes.io/master
    ---
    apiServer:
      extraArgs:
        authorization-mode: Node,RBAC
        authentication-token-webhook-config-file: /webhook/webhook-config.yaml
      extraVolumes:
      - name: "webhook-conf"
        hostPath: "/webhook/"
        mountPath: "/webhook/"
        readOnly: true
        pathType: DirectoryOrCreate
      timeoutForControlPlane: 4m0s
    apiVersion: kubeadm.k8s.io/v1beta2
    certificatesDir: /etc/kubernetes/pki
    clusterName: kubernetes
    controllerManager: {}
    dns:
      type: CoreDNS
    etcd:
      local:
        dataDir: /var/lib/etcd
    imageRepository: k8s.gcr.io
    kind: ClusterConfiguration
    kubernetesVersion: v1.15.10
    networking:
      dnsDomain: cluster.local
      podSubnet: 10.244.0.0/16
      serviceSubnet: 10.96.0.0/12
    scheduler: {}