leonqinliang.github.io

Installing RKE Cluster From Scratch

Step 1: Create VirtualBox VMs

Hardware Requirements

2 CPUs
2GB RAM
15GB disk space for OS
choose “NAT Networks” for VM network type

OS Requirements

choose “openSUSE” as OS type
install openSUSE LEAP
disable firewall service at installation

Step 2: Configure Linux OS

Update OS

zypper up

Disable SELinux

To do

Disable Firewall(if not)

systemctl disable firewalld.service

systemctl stop firewalld.service

Enable IPv4 Forwarding and Iptables can see the bridged traffic

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

sudo modprobe overlay

sudo modprobe br_netfilter

Sysctl Parameters Required by Setup

cat <<EOF | sudo tee /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-iptables = 1
net.bridge.bridge-nf-call-ip6tables = 1
net.ipv4.ip_forward = 1
EOF

Apply Sysctl Parameters without Reboot

sudo sysctl --system

Install Containerd

Find latest version of containerd at this github repository.

Download the gz file and run:

tar Cxzvf /usr/local containerd-1.7.2-linux-amd64.tar.gz

Download the service file. The actual content is as below. You can copy and paste directly into a file named ‘containerd.service’.

# Copyright The containerd Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

[Unit]
Description=containerd container runtime
Documentation=https://containerd.io
After=network.target local-fs.target

[Service]
#uncomment to enable the experimental sbservice (sandboxed) version of containerd/cri integration
#Environment="ENABLE_CRI_SANDBOXES=sandboxed"
ExecStartPre=-/sbin/modprobe overlay
ExecStart=/usr/local/bin/containerd

Type=notify
Delegate=yes
KillMode=process
Restart=always
RestartSec=5
# Having non-zero Limit*s causes performance problems due to accounting overhead
# in the kernel. We recommend using cgroups to do container-local accounting.
LimitNPROC=infinity
LimitCORE=infinity
LimitNOFILE=infinity
# Comment TasksMax if your systemd version does not supports it.
# Only systemd 226 and above support this version.
TasksMax=infinity
OOMScoreAdjust=-999

[Install]
WantedBy=multi-user.target

Make a directory for containerd

mkdir -p /usr/local/lib/systemd/system/

Copy the service file into the directory

cp containerd.service /usr/local/lib/systemd/system/

Start containerd service

systemctl daemon-reload

systemctl enable --now containerd.service

Install runc

Download the binary from https://github.com/opencontainers/runc/releases

Use below commands to install:

install -m 755 runc.amd64 /usr/local/sbin/runc

Disable Swap

swapoff -a

Make sure the swap is disabled

vim /etc/fstab

Mark the swap space with comment mark ‘#’

Install CNI Plugin

Download the latest version here.

Make a directory for install CNI plugin

mkdir -p /opt/cni/bin/

Install CNI plugin

sudo tar -C /opt/cni/bin/ -xzf cni-plugins-linux-amd64-v1.3.0.tgz

Configure cgroup driver

Generate default configuration file

containerd config default > /etc/containerd/config.toml

Set “systemd” as cgroup driver

vim /etc/containerd/config.toml

[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc]
 ...
 [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc.options]
 SystemdCgroup = true

then restart containerd service

systemctl restart containerd.service

Configure ssh auto authentication

Generating public/private key pair

ssh-keygen

Copy public key to all worker nodes

ssh-copy-id root@rke-worker01

Verify the auto-authentication function

ssh root@rke-worker01