Kubernetes_Troubleshooting.txt

# error "The connection to the server localhost:8080 was refused - did you specify the right host or port?"
export KUBECONFIG=/etc/kubernetes/admin.conf
kubectl get nodes

#make sure swap is off
sudo swapon -s
sudo sed -i '/ swap / s/^/#/' /etc/fstab
init 6
# reboot the PC

# kubeadm reissue init token info
kubeadm token create --print-join-command

# source: https://itnext.io/kubernetes-monitoring-with-prometheus-in-15-minutes-8e54d1de2e13

## setup lens for Kubernetes
# get kubeconfig information
cat /etc/kubernetes/kubelet.conf

# copy pam file to local folder
/var/lib/kubelet/pki/   C:\Users\owner\AppData\Roaming\Lens\kubeconfigs\var\lib\kubelet\pki

# pull images for kubeadm
kubeadm config images pull

# start kubernetes host cluster
kubeadm init
# if 'Found multiple CRI sockets' error then,   kubeadm init --cri-socket /var/run/crio/crio.sock

cp cni.kubeconfig /etc/cni/net.d/calico-kubeconfig
chmod 600 /etc/cni/net.d/calico-kubeconfig

## miniKube setup
# source: https://minikube.sigs.k8s.io/docs/start/

curl -LO https://storage.googleapis.com/minikube/releases/latest/minikube_latest_amd64.deb
sudo dpkg -i minikube_latest_amd64.deb



### Delete Resources Stuck in 'Terminating' Status #source: https://stackoverflow.com/questions/52369247/namespace-stuck-as-terminating-how-i-removed-it/66118514#66118514
export RESOURCE=namespaces
export RESOURCENAME=

echo kubectl patch $RESOURCE $RESOURCENAME -p '{"metadata":{"finalizers":null}}'

kubectl patch $RESOURCE $RESOURCENAME -p '{"metadata":{"finalizers":null}}'
kubectl get namespaces

OR

kubectl get namespaces
export NAMESPACE=platform
kubectl get namespace $NAMESPACE -o json > $NAMESPACE-tempfile.json
# remove from json '"finalizers": [ "kubernetes"]'
kubectl replace --raw "/api/v1/namespaces/$NAMESPACE/finalize" -f ./$NAMESPACE-tempfile.json
kubectl get namespaces

OR

NS=`kubectl get ns | grep Terminating | awk 'NR==1 {print $1}'` && kubectl get namespace "$NS" -o json   | tr -d "\n" | sed "s/\"finalizers\": \[[^]]\+\]/\"finalizers\": []/"   | kubectl replace --raw /api/v1/namespaces/$NS/finalize -f -
echo $NS

export RESOURCE=namespaces
kubectl patch $RESOURCE $NS --type='json' -p='[{"op": "replace", "path": "/spec/template/spec/containers/0/image", "value":"<new_image_name>"}]'

example:
kubectl patch statefulset jenkins --type='json' -p='[{"op": "replace", "path": "/spec/template/spec/containers/0/image", "value":"jenkins/jenkins:2.446-alpine-jdk21"}]'


journalctl -u kubelet