Install the Kubernetes Tutorial (KLTS version)¶

This article takes KLTS (Kubernetes Long Term Support) self-maintained by DaoCloud as an example to briefly introduce how to install Kubernetes.

Preparation¶

• Prepare a compatible Linux host. The Kubernetes project for Linux based on Debian and Red Hat Distributions, and some distributions that don't provide a package manager, provide common instructions.
• At least 2 GB or more of memory per host (too little memory will affect the operation of the application)
• CPU 2 cores or more
• Network connectivity of all hosts in the cluster (public and intranet)
• No duplicate hostname, MAC address or product_uuid on a single node, see Ensure uniqueness of MAC address and product_uuid on each node
• Open some ports on the host, see Check Required Ports.
• Disable swap partition. In order for the kubelet to work properly, you must disable swap.

Keep the uniqueness of MAC and product_uuid on the node¶

• Use the command ip link or ifconfig -a to get the MAC address of the network interface
• Use sudo cat /sys/class/dmi/id/product_uuid command to verify product_uuid

Generally speaking, hardware devices have unique addresses, but the addresses of some virtual machines may be repeated. Kubernetes uses the MAC address and product_uuid to identify unique nodes in the cluster. If these values are not unique on each node, it may cause the installation to fail.

Check Network Adapter¶

If you have more than one network adapter and your Kubernetes components are not reachable via default routes, We recommend that you pre-add IP routing rules so that Kubernetes clusters can be connected through corresponding adapters.

Allow iptables to inspect bridged traffic¶

Make sure the br_netfilter module is loaded. This can be done by running lsmod | grep br_netfilter To be done. To explicitly load this module, run the command sudo modprobe br_netfilter .

In order for iptables on your Linux nodes to properly see bridged traffic, you need to ensure that the Set net.bridge.bridge-nf-call-iptables to 1 in sysctl configuration. For example:

cat <<EOF | sudo tee /etc/modules-load.d/k8s.conf
br_netfilter
EOF

cat <<EOF | sudo tee /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables=1
net.bridge.bridge-nf-call-iptables=1
EOF
sudo sysctl --system

For more details, please refer to the Network Plugin Requirements page.

Check required ports¶

Control Plane Node¶

Worker nodes¶

The above is the default port range of NodePort service.

Any port number marked with * can be overridden, so you need to make sure the custom port is open.

Although the control plane nodes already include ports for etcd, you can also use a custom external etcd cluster, or specify a custom port.

The Pod networking plugin (see below) you use may also require certain ports to be open. Since individual Pod network plugins are different, please refer to the appropriate documentation for port requirements.

Set node name¶

The syntax of the command is as follows:

hostnamectl set-hostname your-new-host-name
echo "127.0.0.1 $(hostname)" >> /etc/hosts
echo "::1 $(hostname)" >> /etc/hosts

Close Swap¶

Run the following command to close Swap:

swapoff -a

If you need to shut down permanently, please edit the /etc/fstab file and comment out the mount path of Swap.

Shutdown Selinux¶

Run the following command to shut down Selinux:

setenforce 0

To disable permanently, edit /etc/sysconfig/selinux and replace SELINUX=enforcing with SELINUX=disabled .

Install the runtime¶

To run containers in Pods, Kubernetes uses a Container Runtime.

If it is a Linux node¶

By default, Kubernetes uses the Container Runtime Interface (CRI) to interact with the container runtime of your choice.

If you do not specify a runtime, kubeadm automatically tries to detect a runtime already installed on the system by scanning a set of well-known Unix domain sockets.

The following table lists some container runtimes and their corresponding socket paths:

If both Docker and Containerd are detected, Docker will be preferred. This is true even if you only have Docker installed, since Docker 18.09 ships with Containerd, so both are detectable. If two or more other runtimes are detected, kubeadm outputs an error message and exits.

The kubelet integrates with Docker through the built-in dockershim CRI.

For Docker

yum install docker

apt-get install docker.io

for containerd

By default, containerd only provides download packages for the amd64 architecture. If you use other infrastructures, The containerd.io package can be installed from the official Docker repository. In Install Docker Engine Find instructions on setting up a Docker repository and installing the containerd.io package for your respective Linux distribution.

It can also be built using the following source code.

VERSION=1.5.4
wget -c https://github.com/containerd/containerd/releases/download/v${VERSION}/containerd-${VERSION}-linux-amd64.tar.gz
tar xvf containerd-${VERSION}-linux-amd64.tar.gz -C /usr/local/
mkdir /etc/containerd/ && containerd config default > /etc/containerd/config.toml
wget -c -O /etc/systemd/system/containerd.service https://raw.githubusercontent.com/containerd/containerd/main/containerd.service
systemctl start containerd && systemctl enable containerd

If other OS¶

By default, kubeadm uses docker as the container runtime. The kubelet integrates with Docker through the built-in dockershim CRI.

For Docker

yum install docker

apt-get install docker.io

for containerd

By default, containerd only provides download packages for the amd64 architecture. If you use other infrastructures, The containerd.io package can be installed from the official Docker repository. In Install Docker Engine Find instructions on setting up a Docker repository and installing the containerd.io package for your respective Linux distribution.

It can also be built using the following source code.

VERSION=1.5.4
wget -c https://github.com/containerd/containerd/releases/download/v${VERSION}/containerd-${VERSION}-linux-amd64.tar.gz
tar xvf containerd-${VERSION}-linux-amd64.tar.gz -C /usr/local/
mkdir /etc/containerd/ && containerd config default > /etc/containerd/config.toml
wget -c -O /etc/systemd/system/containerd.service https://raw.githubusercontent.com/containerd/containerd/main/containerd.service
systemctl start containerd && systemctl enable containerd

See Container Runtimes for more information.

Install KLTS¶

KLTS provides installation methods based on deb and rpm software sources, and you can choose the appropriate installation method.

Set KLTS software source¶

VERSION=1.18.20-lts.2
cat << EOF > /etc/yum.repos.d/klts.repo
[klts]
name=klts
baseurl=https://raw.githubusercontent.com/klts-io/kubernetes-lts/rpm-v${VERSION}/\$basearch/
enabled=1
gpgcheck=0
[klts-other]
name=klts-others
baseurl=https://raw.githubusercontent.com/klts-io/others/rpm/\$basearch/
enabled=1
gpgcheck=0
EOF

yum makecache

VERSION=1.18.20-lts.2
cat << EOF > /etc/apt/sources.list.d/klts.list
deb [trusted=yes] https://raw.githubusercontent.com/klts-io/kubernetes-lts/deb-v${VERSION} stable main
deb [trusted=yes] https://raw.githubusercontent.com/klts-io/others/deb stable main
EOF

apt-get update

 The following accelerations are all from third parties, and the safety and stability are not guaranteed. It is only recommended to be used in a test environment!!!

 ```bash
 curl https://raw.githubusercontent.com/wzshiming/github-hosts/master/hosts >>/etc/hosts

 VERSION=1.18.20-lts.2
 cat << EOF > /etc/yum.repos.d/klts.repo
 [klts]
 name=klts
 baseurl=https://raw.githubusercontent.com/klts-io/kubernetes-lts/rpm-v${VERSION}/\$basearch/
 enabled=1
 gpgcheck=0
 [klts-other]
 name=klts-others
 baseurl=https://raw.githubusercontent.com/klts-io/others/rpm/\$basearch/
 enabled=1
 gpgcheck=0
 EOF

 yum makecache
 ```

 ```bash
 VERSION=1.18.20-lts.2
 cat << EOF > /etc/yum.repos.d/klts.repo
 [klts]
 name=klts
 baseurl=https://hub.fastgit.org/klts-io/kubernetes-lts/raw/rpm-v${VERSION}/\$basearch/
 enabled=1
 gpgcheck=0
 [klts-other]
 name=klts-others
 baseurl=https://hub.fastgit.org/klts-io/others/raw/rpm/\$basearch/
 enabled=1
 gpgcheck=0
 EOF

 yum makecache
 ```

 ```bash
 VERSION=1.18.20-lts.2
 cat << EOF > /etc/yum.repos.d/klts.repo
 [klts]
 name=klts
 baseurl=https://ghproxy.com/https://raw.githubusercontent.com/klts-io/kubernetes-lts/rpm-v${VERSION}/\$basearch/
 enabled=1
 gpgcheck=0
 [klts-other]
 name=klts-others
 baseurl=https://ghproxy.com/https://raw.githubusercontent.com/klts-io/others/rpm/\$basearch/
 enabled=1
 gpgcheck=0
 EOF

 yum makecache
 ```

 ```bash
 VERSION=1.18.20-lts.2
 cat << EOF > /etc/yum.repos.d/klts.repo
 [klts]
 name=klts
 baseurl=https://raw.githubusercontents.com/klts-io/kubernetes-lts/rpm-v${VERSION}/\$basearch/
 enabled=1
 gpgcheck=0
 [klts-other]
 name=klts-others
 baseurl=https://raw.githubusercontents.com/klts-io/others/rpm/\$basearch/
 enabled=1
 gpgcheck=0
 EOF

 yum makecache
 ```

 ```bash
 VERSION=1.18.20-lts.2
 cat << EOF > /etc/yum.repos.d/klts.repo
 [klts]
 name=klts
 baseurl=https://raw.staticdn.net/klts-io/kubernetes-lts/rpm-v${VERSION}/\$basearch/
 enabled=1
 gpgcheck=0
 [klts-other]
 name=klts-others
 baseurl=https://raw.staticdn.net/klts-io/others/rpm/\$basearch/
 enabled=1
 gpgcheck=0
 EOF

 yum makecache
 ```

 The following accelerations are all from third parties, and the safety and stability are not guaranteed. It is only recommended to be used in a test environment!!!

 ```bash
 curl https://raw.githubusercontent.com/wzshiming/github-hosts/master/hosts >>/etc/hosts

 VERSION=1.18.20-lts.2
 cat << EOF > /etc/apt/sources.list.d/klts.list
 deb [trusted=yes] https://raw.githubusercontent.com/klts-io/kubernetes-lts/deb-v${VERSION} stable main
 deb [trusted=yes] https://raw.githubusercontent.com/klts-io/others/deb stable main
 EOF

 apt-get update
 ```

VERSION=1.18.20-lts.2
cat << EOF > /etc/apt/sources.list.d/klts.list
deb [trusted=yes] https://hub.fastgit.org/klts-io/kubernetes-lts/raw/deb-v${VERSION} stable main
deb [trusted=yes] https://hub.fastgit.org/klts-io/others/raw/deb stable main
EOF

apt-get update

VERSION=1.18.20-lts.2
cat << EOF > /etc/apt/sources.list.d/klts.list
deb [trusted=yes] https://ghproxy.com/https://raw.githubusercontent.com/klts-io/kubernetes-lts/deb-v${VERSION} stable main
deb [trusted=yes] https://ghproxy.com/https://raw.githubusercontent.com/klts-io/others/deb stable main
EOF

apt-get update

VERSION=1.18.20-lts.2
cat << EOF > /etc/apt/sources.list.d/klts.list
deb [trusted=yes] https://raw.githubusercontents.com/klts-io/kubernetes-lts/deb-v${VERSION} stable main
deb [trusted=yes] https://raw.githubusercontents.com/klts-io/others/deb stable main
EOF

apt-get update

VERSION=1.18.20-lts.2
cat << EOF > /etc/apt/sources.list.d/klts.list
deb [trusted=yes] https://raw.staticdn.net/klts-io/kubernetes-lts/deb-v${VERSION} stable main
deb [trusted=yes] https://raw.staticdn.net/klts-io/kubernetes-lts/deb stable main
EOF

apt-get update

Start installing KLTS¶

yum install kubeadm kubelet kubectl

apt-get install kubeadm kubelet kubectl

Automatically start Kubelet at boot¶

Run the following command to automatically start Kubelet on boot:

systemctl enable kubelet

Pull dependent image¶

VERSION=1.18.20-lts.2
REPOS=ghcr.io/klts-io/kubernetes-lts
kubeadm config images pull --image-repository ${REPOS} --kubernetes-version v${VERSION}

VERSION=1.18.20-lts.2
REPOS=ghcr.m.daocloud.io/klts-io/kubernetes-lts
kubeadm config images pull --image-repository ${REPOS} --kubernetes-version v${VERSION}

Subsequent operations on kubeadm need to add --image-repository and --kubernetes-version to actively specify the image.

Initialize control plane nodes¶

VERSION=1.18.20-lts.2
REPOS=ghcr.io/klts-io/kubernetes-lts
kubeadm init --image-repository ${REPOS} --kubernetes-version v${VERSION}

VERSION=1.18.20-lts.2
REPOS=ghcr.m.daocloud.io/klts-io/kubernetes-lts
kubeadm init --image-repository ${REPOS} --kubernetes-version v${VERSION}

Script one-click installation¶

In addition to the above normal installation methods, KLTS also supports scripts to automate the installation process.

wget https://github.com/klts-io/klts/raw/main/install.sh
chmod +x install.sh
./install.sh

Usage: ./install.sh [OPTIONS]
  -h, --help : Display this help and exit
  --kubernetes-container-registry=ghcr.io/klts-io/kubernetes-lts : Kubernetes container registry
  --kubernetes-version=1.18.20-lts.1 : Kubernetes version to install
  --containerd-version=1.3.10-lts.0 : Containerd version to install
  --runc-version=1.0.2-lts.0 : Runc version to install
  --kubernetes-rpm-source=https://github.com/klts-io/kubernetes-lts/raw/rpm-v1.18.20-lts.2 : Kubernetes RPM source
  --containerd-rpm-source=https://github.com/klts-io/containerd-lts/raw/rpm-v1.3.10-lts.0 : Containerd RPM source
  --runc-rpm-source=https://github.com/klts-io/runc-lts/raw/rpm-v1.0.2-lts.0 : Runc RPM source
  --others-rpm-source=https://github.com/klts-io/others/raw/rpm : Other RPM source
  --kubernetes-deb-source=https://github.com/klts-io/kubernetes-lts/raw/deb-v1.18.20-lts.2 : Kubernetes DEB source
  --containerd-deb-source=https://github.com/klts-io/containerd-lts/raw/deb-v1.3.10-lts.0 : Containerd DEB source
  --runc-deb-source=https://github.com/klts-io/runc-lts/raw/deb-v1.0.2-lts.0 : Runc DEB source
  --others-deb-source=https://github.com/klts-io/others/raw/deb : Other DEB source
  --focus=enable-iptables-discover-bridged-traffic,disable-swap,disable-selinux,setup-source,install-kubernetes,install-containerd,install-runc,install-crictl,install-cniplugins,setup-crictl-config,setup-containerd-cni-config,setup-kubelet-config,setup-containerd-config,daemon-reload,start-containerd,status-containerd,enable-containerd,start-kubelet,status-kubelet,enable-kubelet,images-pull,control-plane-init,status-nodes,show-join-command : Focus on specific step
  --skip='' : Skip on specific step

More ways to install¶

• Nanny deployment three-node K8s cluster
• Using kubeadm to create a cluster
• Install K8s with kOps
• Install K8s using Kubespray

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