The connection to the server x.x.x.:6443 was refused - did you specify the right host or port? Kubernetes

Please perform below steps on the master node. It works like charm.

1. sudo -i

2. swapoff -a

3. exit

4. strace -eopenat kubectl version

I am facing similar problem with following error while deploying the pod network into a cluster using flannel:

$ kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
The connection to the server 192.168.1.101:6443 was refused - did you specify the right host or port?

I performed below steps to solved the issue:

$ sudo systemctl stop kubelet
$ sudo systemctl start kubelet
$ strace -eopenat kubectl version

then apply the yml file

$ kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
podsecuritypolicy.policy/psp.flannel.unprivileged created
clusterrole.rbac.authorization.k8s.io/flannel created
clusterrolebinding.rbac.authorization.k8s.io/flannel created
serviceaccount/flannel created
configmap/kube-flannel-cfg created
daemonset.apps/kube-flannel-ds created

kubelet must be down. you need to check kubelet logs on the master and ensure api server is running and online. then only you should be able to deploy

I'll add another reason for this error that was the issue in my case.

I exported the wrong Kubeconfig file to shell and the error message was very accurate in that case - The endpoint for the API server was wrong (and of course other fields like the cluster name and the certificates - but the server endpoint is the first step in the chain).

I've encountered this problem and swapoff -a works for me though.

sudo -i
swapoff -a
exit
strace -eopenat kubectl version

Assuming that's all the output from your netstat command and that you ran it on the master node (the one you installed Kubernetes via kubadm on), it looks to me like the installation did not complete correctly as none of the usual ports you would expect to see on a Kubernetes master node are present.

Usually on a kubernetes master node you'd expect to see kube-apiserver, kube-scheduler, kube-controller, kubelet and possibly etcd all listening on the network.

What was the output of your kubeadm init command?

I ran into this issue as well, I tried the solutions noted above and it did not work for me. Here is what worked for me:

FIX: kubeadm init --apiserver-advertise-address=10.139.0.42 --ignore-preflight-errors all --pod-network-cidr=172.17.0.1/16 --token-ttl 0

source: https://www.c-sharpcorner.com/article/kubernetes-installation-in-redhat-and-centos/

I faced this issue recently due to expired certificates for my K8S cluster. I followed this blog link to renew the certificates and also replace the kube config file that I was using. Note, it is important to replace the kube config post renewal of the certificates or else you would end up getting following error message for kubectl CLIs:

error: You must be logged in to the server (Unauthorized)

This is because docker is down. Start docker on your machine.

I have tried many ways but couldn't get it work, then accidentally found the solution to my own situation:

In ~/.kube/ I have

drwxr-x---   4  staff   128 25 Jul 22:31 cache
-rw-------   1  staff  8781 25 Jul 22:46 config
drwxr-xr-x   8  staff   256 25 Jul 22:46 configs
-rw-r--r--   1  staff    14 25 Jul 22:31 kubectx
drwxr-xr-x   4  staff   128 29 Jun 16:59 kubens

My assumption is that there is something messed up in the .kube configuration, however I couldn't figure out which files, so I removed most of the directories/files, including cache, config. (If you don't want to keep all the configs, maybe you should remove all of them)

Then from docker dashboard to re-enable kubernetes, to get all the files installed back.

Re-config the docker-desktop by kubectl config use-context docker-desktop.

Finally, my 6443 responded.

I faced same issue with the same error, You need to check that your container run time (docker/containerd) is active and running:

systemctl status containerd
systemctl restart containerd

systemctl restart kubelet

then if you check its status, it supposed to be up and running and you are able to create k8s objects right now.

In my case KUBECONFIG was the problem causing the same error.

This solved it:

export KUBECONFIG=/home/$(whoami)/.kube/config

As per the error message, it is clearly says port number 6443 connection is refused.

Means

1. port number is blocked by firewall
2. if there is no firewall, then

Blockquote

the port number is not running on the specified host 6443. you can cross verify using the below command #netstat -tulpn | grep -i 6443.

Solution: 6443 it is kube-apiserver port number in k8s. if it is not running make sure kube-apiserver is running properly. I have faced the same problem. After that I have fix properly set the correct argument in that specific port.

/usr/local/bin/kube-apiserver \\
  --advertise-address=${INTERNAL_IP} \\
  --allow-privileged=true \\
  --apiserver-count=3 \\
  --audit-log-maxage=30 \\
  --audit-log-maxbackup=3 \\
  --audit-log-maxsize=100 \\
  --audit-log-path=/var/log/audit.log \\
  --authorization-mode=Node,RBAC \\
  --bind-address=0.0.0.0 \\
  --client-ca-file=/var/lib/kubernetes/ca.crt \\
  --enable-admission-plugins=NodeRestriction,ServiceAccount \\
  --enable-swagger-ui=true \\
  --enable-bootstrap-token-auth=true \\
  --etcd-cafile=/var/lib/kubernetes/ca.crt \\
  --etcd-certfile=/var/lib/kubernetes/etcd-server.crt \\
  --etcd-keyfile=/var/lib/kubernetes/etcd-server.key \\
  --etcd-servers=https://192.168.5.11:2379,https://192.168.5.12:2379 \\
  --event-ttl=1h \\
  --encryption-provider-config=/var/lib/kubernetes/encryption-config.yaml \\
  --kubelet-certificate-authority=/var/lib/kubernetes/ca.crt \\
  --kubelet-client-certificate=/var/lib/kubernetes/kube-apiserver.crt \\
  --kubelet-client-key=/var/lib/kubernetes/kube-apiserver.key \\
  --kubelet-https=true \\
  --runtime-config=api/all \\
  --service-account-key-file=/var/lib/kubernetes/service-account.crt \\
  --service-cluster-ip-range=10.96.0.0/24 \\
  --service-node-port-range=30000-32767 \\
  --tls-cert-file=/var/lib/kubernetes/kube-apiserver.crt \\
  --tls-private-key-file=/var/lib/kubernetes/kube-apiserver.key \\
  --v=2

sudo -i
swapoff -a
exit
strace -eopenat kubectl version