Ulitimate CKA exam mock series exam 4: Q3

Hi Team,

Solution specified for the question mentioned below in the mock exam is NOT resolving the issue. Kindly assist with this. Thanks!

Q:

Solve this question on: ssh cluster4-controlplane


Identify and fix the issue that occurs while running kubectl commands on cluster4?

My solution

cluster4-controlplane ~ ➜  k get pods
The connection to the server cluster4-controlplane:6443 was refused - did you specify the right host or port?

cluster4-controlplane ~ ✖ cat /etc/kubernetes/manifests/kube-apiserver.yaml 
apiVersion: v1
kind: Pod
metadata:
  annotations:
    kubeadm.kubernetes.io/kube-apiserver.advertise-address.endpoint: 192.168.13.250:6443
  creationTimestamp: null
  labels:
    component: kube-apiserver
    tier: control-plane
  name: kube-apiserver
  namespace: kube-system
spec:
  containers:
  - command:
    - kube-apiserver
    - --advertise-address=192.168.13.250
    - --allow-privileged=true
    - --authorization-mode=Node,RBAC
    - --client-ca-file=/etc/kubernetes/pki/ca.crt
    - --enable-admission-plugins=NodeRestriction
    - --enable-bootstrap-token-auth=true
    - --etcd-cafile=/etc/kubernetes/pki/etcd/ca.crt
    - --etcd-certfile=/etc/kubernetes/pki/apiserver-etcd-client.crt
    - --etcd-keyfile=/etc/kubernetes/pki/apiserver-etcd-client.key
    - --etcd-servers=http://127.0.0.1:2379
    - --kubelet-client-certificate=/etc/kubernetes/pki/apiserver-kubelet-client.crt
    - --kubelet-client-key=/etc/kubernetes/pki/apiserver-kubelet-client.key
    - --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname
    - --proxy-client-cert-file=/etc/kubernetes/pki/front-proxy-client.crt
    - --proxy-client-key-file=/etc/kubernetes/pki/front-proxy-client.key
    - --requestheader-allowed-names=front-proxy-client
    - --requestheader-client-ca-file=/etc/kubernetes/pki/front-proxy-ca.crt
    - --requestheader-extra-headers-prefix=X-Remote-Extra-
    - --requestheader-group-headers=X-Remote-Group
    - --requestheader-username-headers=X-Remote-User
    - --secure-port=6443
    - --service-account-issuer=https://kubernetes.default.svc.cluster.local
    - --service-account-key-file=/etc/kubernetes/pki/sa.pub
    - --service-account-signing-key-file=/etc/kubernetes/pki/sa.key
    - --service-cluster-ip-range=172.20.0.0/16
    - --tls-cert-file=/etc/kubernetes/pki/apiserver.crt
    - --tls-private-key-file=/etc/kubernetes/pki/apiserver.key
    image: registry.k8s.io/kube-apiserver:v1.32.0
    imagePullPolicy: IfNotPresent
    livenessProbe:
      failureThreshold: 8
      httpGet:
        host: 192.168.13.250
        path: /livez
        port: 6443
        scheme: HTTPS
      initialDelaySeconds: 10
      periodSeconds: 10
      timeoutSeconds: 15
    name: kube-apiserver
    readinessProbe:
      failureThreshold: 3
      httpGet:
        host: 192.168.13.250
        path: /readyz
        port: 6443
        scheme: HTTPS
      periodSeconds: 1
      timeoutSeconds: 15
    resources:
      requests:
        cpu: 250m
    startupProbe:
      failureThreshold: 24
      httpGet:
        host: 192.168.13.250
        path: /livez
        port: 6443
        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/kubernetes/pki
      name: k8s-certs
      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
  priority: 2000001000
  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/kubernetes/pki
      type: DirectoryOrCreate
    name: k8s-certs
  - 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: {}

cluster4-controlplane ~ ➜  k get pods
The connection to the server cluster4-controlplane:6443 was refused - did you specify the right host or port?

cluster4-controlplane ~ ✖ crictl  ps -a 
CONTAINER           IMAGE               CREATED              STATE               NAME                      ATTEMPT             POD ID              POD                                             NAMESPACE
5c9628d1be750       6331715a2ae96       53 seconds ago       Running             calico-kube-controllers   15                  1dda7ea052795       calico-kube-controllers-5745477d4d-c9v78        kube-system
a0a9af6666442       6331715a2ae96       About a minute ago   Exited              calico-kube-controllers   14                  1dda7ea052795       calico-kube-controllers-5745477d4d-c9v78        kube-system
44096bb1db21f       c2e17b8d0f4a3       About a minute ago   Exited              kube-apiserver            8                   ae1bbe1186475       kube-apiserver-cluster4-controlplane            kube-system
167569426c22b       a389e107f4ff1       35 minutes ago       Running             kube-scheduler            1                   784f02caa94ea       kube-scheduler-cluster4-controlplane            kube-system
bd2e6ff910ad8       8cab3d2a8bd0f       35 minutes ago       Running             kube-controller-manager   1                   d21263f9a0d50       kube-controller-manager-cluster4-controlplane   kube-system
b306797da49db       ead0a4a53df89       About an hour ago    Running             coredns                   0                   af723b01bbb60       coredns-7484cd47db-ps8sf                        kube-system
c935d537b17f0       ead0a4a53df89       About an hour ago    Running             coredns                   0                   e6eb689d9157a       coredns-7484cd47db-vdl6g                        kube-system
07792e16c4ed1       c9fe3bce8a6d8       About an hour ago    Running             kube-flannel              0                   1d2c50873cc11       canal-g6t7d                                     kube-system
196a77e198da9       feb26d4585d68       About an hour ago    Running             calico-node               0                   1d2c50873cc11       canal-g6t7d                                     kube-system
935574c04e1ad       7dd6ea186aba0       About an hour ago    Exited              install-cni               0                   1d2c50873cc11       canal-g6t7d                                     kube-system
a1c8d4a0d6c7d       040f9f8aac8cd       About an hour ago    Running             kube-proxy                0                   42a36957cbf99       kube-proxy-z5256                                kube-system
3f730370d9423       a9e7e6b294baf       About an hour ago    Running             etcd                      0                   0574009ae6a1b       etcd-cluster4-controlplane                      kube-system
f674cb9d8560c       8cab3d2a8bd0f       About an hour ago    Exited              kube-controller-manager   0                   d21263f9a0d50       kube-controller-manager-cluster4-controlplane   kube-system
cd64014121343       a389e107f4ff1       About an hour ago    Exited              kube-scheduler            0                   784f02caa94ea       kube-scheduler-cluster4-controlplane            kube-system

cluster4-controlplane ~ ➜  crictl logs 44096bb1db21f | tail -10 
W0730 02:56:50.023367       1 registry.go:256] calling componentGlobalsRegistry.AddFlags more than once, the registry will be set by the latest flags
I0730 02:56:50.023817       1 options.go:238] external host was not specified, using 192.168.13.250
I0730 02:56:50.025737       1 server.go:143] Version: v1.32.0
I0730 02:56:50.025768       1 server.go:145] "Golang settings" GOGC="" GOMAXPROCS="" GOTRACEBACK=""
W0730 02:56:50.323024       1 logging.go:55] [core] [Channel #1 SubChannel #3]grpc: addrConn.createTransport failed to connect to {Addr: "127.0.0.1:2379", ServerName: "127.0.0.1:2379", }. Err: connection error: desc = "error reading server preface: EOF"
W0730 02:56:50.323030       1 logging.go:55] [core] [Channel #2 SubChannel #4]grpc: addrConn.createTransport failed to connect to {Addr: "127.0.0.1:2379", ServerName: "127.0.0.1:2379", }. Err: connection error: desc = "error reading server preface: EOF"
I0730 02:56:50.323537       1 shared_informer.go:313] Waiting for caches to sync for node_authorizer
I0730 02:56:50.330579       1 shared_informer.go:313] Waiting for caches to sync for *generic.policySource[*k8s.io/api/admissionregistration/v1.ValidatingAdmissionPolicy,*k8s.io/api/admissionregistration/v1.ValidatingAdmissionPolicyBinding,k8s.io/apiserver/pkg/admission/plugin/policy/validating.Validator]
I0730 02:56:50.337906       1 plugins.go:157] Loaded 13 mutating admission controller(s) successfully in the following order: NamespaceLifecycle,LimitRanger,ServiceAccount,NodeRestriction,TaintNodesByCondition,Priority,DefaultTolerationSeconds,DefaultStorageClass,StorageObjectInUseProtection,RuntimeClass,DefaultIngressClass,MutatingAdmissionPolicy,MutatingAdmissionWebhook.
I0730 02:56:50.337932       1 plugins.go:160] Loaded 13 validating admission controller(s) successfully in the following order: LimitRanger,ServiceAccount,PodSecurity,Priority,PersistentVolumeClaimResize,RuntimeClass,CertificateApproval,CertificateSigning,ClusterTrustBundleAttest,CertificateSubjectRestriction,ValidatingAdmissionPolicy,ValidatingAdmissionWebhook,ResourceQuota.
I0730 02:56:50.338168       1 instance.go:233] Using reconciler: lease
W0730 02:56:50.339440       1 logging.go:55] [core] [Channel #7 SubChannel #8]grpc: addrConn.createTransport failed to connect to {Addr: "127.0.0.1:2379", ServerName: "127.0.0.1:2379", }. Err: connection error: desc = "error reading server preface: read tcp 127.0.0.1:40906->127.0.0.1:2379: read: connection reset by peer"
W0730 02:56:51.324226       1 logging.go:55] [core] [Channel #2 SubChannel #4]grpc: addrConn.createTransport failed to connect to {Addr: "127.0.0.1:2379", ServerName: "127.0.0.1:2379", }. Err: connection error: desc = "error reading server preface: read tcp 127.0.0.1:40926->127.0.0.1:2379: read: connection reset by peer"
W0730 02:56:51.324321       1 logging.go:55] [core] [Channel #1 SubChannel #3]grpc: addrConn.createTransport failed to connect to {Addr: "127.0.0.1:2379", ServerName: "127.0.0.1:2379", }. Err: connection error: desc = "error reading server preface: read tcp 127.0.0.1:40924->127.0.0.1:2379: read: connection reset by peer"
W0730 02:56:51.340261       1 logging.go:55] [core] [Channel #7 SubChannel #8]grpc: addrConn.createTransport failed to connect to {Addr: "127.0.0.1:2379", ServerName: "127.0.0.1:2379", }. Err: connection error: desc = "error reading server preface: read tcp 127.0.0.1:40942->127.0.0.1:2379: read: connection reset by peer"
W0730 02:56:52.626315       1 logging.go:55] [core] [Channel #1 SubChannel #3]grpc: addrConn.createTransport failed to connect to {Addr: "127.0.0.1:2379", ServerName: "127.0.0.1:2379", }. Err: connection error: desc = "error reading server preface: EOF"
W0730 02:56:53.009783       1 logging.go:55] [core] [Channel #2 SubChannel #4]grpc: addrConn.createTransport failed to connect to {Addr: "127.0.0.1:2379", ServerName: "127.0.0.1:2379", }. Err: connection error: desc = "error reading server preface: EOF"
W0730 02:56:53.028853       1 logging.go:55] [core] [Channel #7 SubChannel #8]grpc: addrConn.createTransport failed to connect to {Addr: "127.0.0.1:2379", ServerName: "127.0.0.1:2379", }. Err: connection error: desc = "error reading server preface: EOF"
W0730 02:56:55.517032       1 logging.go:55] [core] [Channel #1 SubChannel #3]grpc: addrConn.createTransport failed to connect to {Addr: "127.0.0.1:2379", ServerName: "127.0.0.1:2379", }. Err: connection error: desc = "error reading server preface: EOF"
W0730 02:56:55.727971       1 logging.go:55] [core] [Channel #7 SubChannel #8]grpc: addrConn.createTransport failed to connect to {Addr: "127.0.0.1:2379", ServerName: "127.0.0.1:2379", }. Err: connection error: desc = "error reading server preface: read tcp 127.0.0.1:35776->127.0.0.1:2379: read: connection reset by peer"
W0730 02:56:55.920348       1 logging.go:55] [core] [Channel #2 SubChannel #4]grpc: addrConn.createTransport failed to connect to {Addr: "127.0.0.1:2379", ServerName: "127.0.0.1:2379", }. Err: connection error: desc = "error reading server preface: EOF"
W0730 02:56:59.240064       1 logging.go:55] [core] [Channel #1 SubChannel #3]grpc: addrConn.createTransport failed to connect to {Addr: "127.0.0.1:2379", ServerName: "127.0.0.1:2379", }. Err: connection error: desc = "error reading server preface: read tcp 127.0.0.1:35802->127.0.0.1:2379: read: connection reset by peer"
W0730 02:56:59.885026       1 logging.go:55] [core] [Channel #2 SubChannel #4]grpc: addrConn.createTransport failed to connect to {Addr: "127.0.0.1:2379", ServerName: "127.0.0.1:2379", }. Err: connection error: desc = "error reading server preface: read tcp 127.0.0.1:35804->127.0.0.1:2379: read: connection reset by peer"
W0730 02:57:00.182306       1 logging.go:55] [core] [Channel #7 SubChannel #8]grpc: addrConn.createTransport failed to connect to {Addr: "127.0.0.1:2379", ServerName: "127.0.0.1:2379", }. Err: connection error: desc = "error reading server preface: EOF"
W0730 02:57:04.711572       1 logging.go:55] [core] [Channel #1 SubChannel #3]grpc: addrConn.createTransport failed to connect to {Addr: "127.0.0.1:2379", ServerName: "127.0.0.1:2379", }. Err: connection error: desc = "error reading server preface: EOF"
W0730 02:57:05.134564       1 logging.go:55] [core] [Channel #2 SubChannel #4]grpc: addrConn.createTransport failed to connect to {Addr: "127.0.0.1:2379", ServerName: "127.0.0.1:2379", }. Err: connection error: desc = "error reading server preface: EOF"
W0730 02:57:05.740246       1 logging.go:55] [core] [Channel #7 SubChannel #8]grpc: addrConn.createTransport failed to connect to {Addr: "127.0.0.1:2379", ServerName: "127.0.0.1:2379", }. Err: connection error: desc = "error reading server preface: EOF"
F0730 02:57:10.338902       1 instance.go:226] Error creating leases: error creating storage factory: context deadline exceeded

$ crictl logs 3f730370d9423 | tail -2

{"level":"warn","ts":"2025-07-30T02:57:05.134319Z","caller":"embed/config_logging.go:170","msg":"rejected connection on client endpoint","remote-addr":"127.0.0.1:49724","server-name":"","error":"tls: first record does not look like a TLS handshake"}
{"level":"warn","ts":"2025-07-30T02:57:05.739954Z","caller":"embed/config_logging.go:170","msg":"rejected connection on client endpoint","remote-addr":"127.0.0.1:49730","server-name":"","error":"tls: first record does not look like a TLS handshake"}

Getting the log off the (dead) api server I see the item:

Error: unknown flag: --etcd-server

Probably what is needed you can find in the kube-apiserver reference page:

After that:

  • What’s the argument to the corrected argument? Does it look plausible?
  • Make sure all of the certs are right for etcd.