/k8s-ubuntu

Kubernetes cluster on Ubuntu

k8s-ubuntu

Kubernetes cluster on Ubuntu 18.04(16.04)

links

Configure the Master Node

add hostnames/ip of master and worker modes to /etc/hosts (optional)

install docker, kubeadm, kubelet, kubectl

$ apt-get update && apt-get install -y apt-transport-https
$ curl -s https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
$ add-apt-repository \
    "deb [arch=amd64] https://download.docker.com/linux/ubuntu bionic stable"
$ apt update && apt install -qy docker-ce
$ curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
$ echo "deb http://apt.kubernetes.io/ kubernetes-xenial main" \
    > /etc/apt/sources.list.d/kubernetes.list
$ apt-get update && apt-get install -y kubeadm kubelet kubectl

hold tools versions

sudo apt-mark hold docker-ce kubelet kubeadm kubectl

turn off swap

swapoff -a

Configure Kubernetes

  • kubeadm init --apiserver-advertise-address=<MASTER_IP> --pod-network-cidr=10.244.1.0/16
  • get message (example):
Your Kubernetes master has initialized successfully!

To start using your cluster, you need to run the following as a regular user:

  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config

You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
  https://kubernetes.io/docs/concepts/cluster-administration/addons/

You can now join any number of machines by running the following on each node
as root:

  kubeadm join 192.168.0.15:6443 --token puvb9w.85mnirj5i8nceyaa --discovery-token-ca-cert-hash sha256:<HASH>

Create a new user

adduser ubuntu
usermod -aG sudo ubuntu
su - ubuntu

Set up the Kubernetes config as the new user:

$ mkdir -p ~/.kube
$ sudo cp -i /etc/kubernetes/admin.conf ~/.kube/config
$ sudo chown $(id -u):$(id -g) ~/.kube/config

Deploy a flannel network to the cluster:

kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

Get tocken for join working nodes

  • kubeadm token create
  • get discovery-token-ca-cert-hash:
    • openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | \ openssl dgst -sha256 -hex | sed 's/^.* //'
  • OR kubeadm token create --print-join-command

Configure the Worker Nodes

install docker, kubeadm, kubelet, kubectl

$ apt-get update && apt-get install -y apt-transport-https
$ curl -s https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
$ add-apt-repository \
    "deb [arch=amd64] https://download.docker.com/linux/ubuntu bionic stable"
$ apt update && apt install -qy docker-ce
$ curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
$ echo "deb http://apt.kubernetes.io/ kubernetes-xenial main" \
    > /etc/apt/sources.list.d/kubernetes.list
$ apt-get update && apt-get install -y kubeadm kubelet kubectl

hold tools versions

sudo apt-mark hold docker-ce kubelet kubeadm kubectl

turn off swap

swapoff -a

Configure Kubernetes

kubeadm join 192.168.0.15:6443 --token puvb9w.85mnirj5i8nceyaa --discovery-token-ca-cert-hash sha256:<HASH>

if tocken expired

  • kubeadm token create --print-join-command

if join problem:

  • kubeadm join -v=6 ...
  • /usr/bin/kubeadm reset
  • run again kubeadm join ...

Check

  • kubectl get nodes
  • kubectl get pods --all-namespaces
  • kubectl get all --all-namespaces

Dashboard

  • kubectl create -f https://raw.githubusercontent.com/kubernetes/dashboard/master/aio/deploy/recommended/kubernetes-dashboard.yaml
  • kubectl proxy

Config Gitlab

  • kubectl get secrets

install docker (2-nd way)

# Install Docker CE
## Set up the repository:
### Install packages to allow apt to use a repository over HTTPS
apt-get update && apt-get install apt-transport-https ca-certificates curl software-properties-common

### Add Docker’s official GPG key
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | apt-key add -

### Add Docker apt repository.
add-apt-repository \
  "deb [arch=amd64] https://download.docker.com/linux/ubuntu \
  $(lsb_release -cs) \
  stable"

## Install Docker CE.
apt-get update && apt-get install docker-ce=18.06.2~ce~3-0~ubuntu

# Setup daemon.
cat > /etc/docker/daemon.json <<EOF
{
  "exec-opts": ["native.cgroupdriver=systemd"],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "100m"
  },
  "storage-driver": "overlay2"
}
EOF

mkdir -p /etc/systemd/system/docker.service.d

# Restart docker.
systemctl daemon-reload
systemctl restart docker