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linux:ubuntu:kubernetes

Kubernetes

Installation

Add the Repository,install “kubelet” + “kubeadm” + “kubectl” and set the updates on hold

curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add - && \
  echo "deb http://apt.kubernetes.io/ kubernetes-xenial main" | sudo tee /etc/apt/sources.list.d/kubernetes.list && \
  sudo apt-get update -q && \
  sudo apt-get install -qy kubelet kubeadm kubectl
  apt-mark hold kubelet kubeadm kubectl

Configuration

master

Pull images used by kubeadm

kubeadm config images pull

Set up the ip configuration, the “apiserver-advertise-address” has to be your management ip

kubeadm init --apiserver-advertise-address=10.0.0.2 --pod-network-cidr=192.168.0.0/16                               
#kubeadm init --pod-network-cidr=192.168.0.0/16

You may run into the following warnings and errors

[init] Using Kubernetes version: v1.16.2
[preflight] Running pre-flight checks
        [WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/
        [WARNING SystemVerification]: this Docker version is not on the list of validated versions: 19.03.4. Latest validated version: 18.09
error execution phase preflight: [preflight] Some fatal errors occurred:
        [ERROR Swap]: running with swap on is not supported. Please disable swap
[preflight] If you know what you are doing, you can make a check non-fatal with `--ignore-preflight-errors=...`
To see the stack trace of this error execute with --v=5 or higher

To fix the error, disable swap

swapoff -a

#should be 0 now
free -m
              total        used        free      shared  buff/cache   available
Mem:           xxxx         xxx        xxxx         xxx        xxxx        xxxx
Swap:             0           0           0

Execute the ip configuration again, which should now be possible.

If the initialization was successful, create a new user.

useradd -s /bin/bash -m kubernetes                                       
su - kubernetes
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

Next you need to deploy a pod network.
Find some here: https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/create-cluster-kubeadm/#pod-network

I use calico, which can be deployed via

kubectl apply -f https://docs.projectcalico.org/v3.8/manifests/calico.yaml

Dashboard

Find the dashboard for your kubernetes version here:
https://github.com/kubernetes/dashboard/releases

You can see your version via

kubeadm version

Commands

Command Function
kubectl get pods --all-namespaces show pods
kubeadm reset reverts changes made via “kubeadm init” and “kubeadm join”

Troubleshooting

Placeholder

Reason:

Fix:


Offene Fragen...

  • cgroup driver?!

https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/#configure-cgroup-driver-used-by-kubelet-on-control-plane-node

Please mind, that you only have to do that if the cgroup driver of your CRI is not cgroupfs, because that is the default value in the kubelet already.

ABER

[WARNING IsDockerSystemdCheck]: detected “cgroupfs” as the Docker cgroup driver. The recommended driver is “systemd”. Please follow the guide at https://kubernetes.io/docs/setup/cri/

Reason why

https://github.com/kubernetes/kubeadm/issues/1394#issuecomment-462878219

  • validated version of docker?

[WARNING SystemVerification]: this Docker version is not on the list of validated versions: 19.03.4. Latest validated version: 18.09

  • management ip

https://github.com/kubernetes/kubernetes/issues/33618

kubectl edit deployment kubernetes-dashboard -n kube-system NAMESPACE anders!!! kein ttl im dashboard

linux/ubuntu/kubernetes.txt · Last modified: 2019/10/23 14:09 by lunetikk